JP5707195B2 - MOTOR TEMPERATURE ESTIMATION DEVICE, POWER GENERATION SYSTEM HAVING THE SAME, AND MOTOR TEMPERATURE ESTIMATION METHOD - Google Patents

Description

  The present invention relates to a technique for estimating the temperature of a rotor in a motor.

  Conventionally, a motor including a stator and a rotor that is rotatable with respect to the stator and provided with a permanent magnet is known. In this type of motor, when the temperature of the rotor exceeds a predetermined temperature, a so-called demagnetization phenomenon occurs in which the magnetic flux density of the permanent magnet is irreversibly lowered. And if the demagnetization of a permanent magnet arises, the performance of a motor will fall. Therefore, in order to use the motor while maintaining the performance of the motor, it is necessary to manage the temperature of the rotor.

  For example, Patent Document 1 discloses a motor having a magnetizing element provided in a rotor so as to be in contact with an upper end surface of a permanent magnet and a Hall element provided in a stator. The magnetization element has a characteristic that the saturation magnetic flux density and the magnetic permeability change depending on the temperature. The Hall element detects the strength of the magnetic field of the magnetizing element. And in the motor of patent document 1, the intensity | strength of the magnetic field of the magnetization element which changes when the temperature of a magnetization element tracks the temperature of a permanent magnet is detected with a Hall element. The temperature of the magnetizing element is specified based on the characteristics of the magnetizing element indicating the relationship between the magnetizing element temperature and the saturation magnetic flux density, and the detected magnetic field strength. The temperature of the specified magnetizing element is the temperature of the permanent magnet. Presumed to be.

JP 2004-222387 A

  However, the motor described in Patent Document 1 has a problem that the amount of information required in advance for estimating the temperature of the permanent magnet increases.

  Specifically, in the motor described in Patent Document 1, the temperature of the permanent magnet is close to the predetermined temperature by employing a magnetizing element having a characteristic that the strength of the magnetic field changes significantly at a predetermined temperature. In order to estimate the temperature of the permanent magnet for a temperature range deviating from the predetermined temperature, information on the temperature of the magnetizing element and the strength of the magnetic field over the entire temperature range that needs to be estimated (for example, patents) It is necessary to prepare and hold the graph of FIG.

  An object of the present invention is to provide a motor temperature estimation device and a motor temperature estimation method capable of reducing the amount of information required in advance for estimating the temperature of a permanent magnet.

  In order to solve the above problems, the inventors of the present application pay attention to the fact that the temperature of the permanent magnet after the temperature change is proportional to the ratio of the magnetic flux density before the temperature change to the magnetic flux density after the temperature change. The inventors have arrived at the following invention in which the temperature after change is estimated by using the magnetic flux density of the permanent magnets before and after and the temperature before change.

  That is, when the temperature before the change is T0, the magnetic flux density of the permanent magnet at that time is B0, the temperature after the change is T1, and the magnetic flux density of the permanent magnet at that time is B1, the relationship of the following equation (1) Is established.

T1 = T0−1 / m × (1−B1 / B0) (1)
Here, m is a coefficient defined by the material of the permanent magnet. Therefore, T1 can be calculated by using T0, B0, and B1, and T1 can be estimated as the temperature of the permanent magnet.

Specifically, the present invention is a temperature estimation device for estimating the temperature of the permanent magnet for a motor having a stator and a rotor that is rotatable with respect to the stator and provided with a permanent magnet. Magnetic flux density specifying means for specifying the magnetic flux density of the permanent magnet, a storage unit for storing the reference magnetic flux density specified by the magnetic flux density specifying means under a condition where the temperature of the permanent magnet is known, and the magnetic flux density a specific magnetic flux density specified by the specifying means, said a known temperature, on the basis of said reference magnetic flux density, a temperature estimation unit that estimates a temperature of the permanent magnet in a particular time of the particular magnetic flux density, the stator provided, further comprising ambient temperature detection section arranged to detect the ambient temperature of the stator, the storage unit stores the temperature detected by the ambient temperature detecting section, To provide a degree estimation device.

  According to the present invention, as described above, the temperature of the permanent magnet can be estimated based on the known temperature, the reference magnetic flux density, and the specific magnetic flux density. For this reason, the amount of information necessary (known temperature and reference magnetic flux density) is reduced in advance compared to the prior art that requires information about the magnetic field strength of the magnetizing element over the entire temperature range necessary for estimation. be able to.

In the present invention, the temperature around the stator can be detected. Therefore, by detecting the ambient temperature under conditions where the ambient temperature and the permanent magnet temperature are substantially equivalent (for example, when starting the motor for the first time or when restarting after stopping for a long time), this temperature is reduced. The known temperature can be used.

  Specifically, the temperature estimation unit can estimate the temperature of the permanent magnet based on the ratio of the reference magnetic flux density to the specific magnetic flux density and the known temperature.

  In the temperature estimation device, the magnetic flux density specifying means is provided in the stator and capable of generating an electromotive force having a magnitude corresponding to the magnitude of the magnetic flux density of the permanent magnet, and the detection It is preferable that a voltage detection unit capable of detecting a voltage applied to the coil for use and a calculation unit for calculating the magnetic flux density of the permanent magnet based on the voltage detected by the voltage detection unit.

  In this aspect, the magnetic flux density specifying unit includes a detection coil, a voltage detection unit, and a calculation unit. Therefore, the magnetic flux density of the permanent magnet can be calculated based on the voltage applied to the detection coil.

  Here, in the said aspect, in order to detect the electromotive force (voltage) which changes according to the magnitude | size of the magnetic flux density of a permanent magnet, compared with a prior art (Unexamined-Japanese-Patent No. 2004-222387), the temperature of a permanent magnet Responsiveness (speed of follow-up) of the change in the estimated temperature with respect to the change can be improved. Specifically, in the prior art, since the strength of the magnetic field of the magnetizing element that has taken heat from the permanent magnet is detected, the time required for heat transfer from the permanent magnet to the magnetizing element becomes a factor that reduces the responsiveness. . On the other hand, in the said aspect, since the temperature is estimated based on the electromotive force produced according to the magnetic flux density of a permanent magnet without going through heat transfer, the said responsiveness can be improved. Furthermore, in the prior art, the temperature of the magnetizing element varies not with the permanent magnet but with the surrounding temperature, and the estimated temperature of the permanent magnet may become inaccurate. On the other hand, in the above aspect, since the temperature of the permanent magnet is estimated based on the electromotive force corresponding to the magnetic flux density of the permanent magnet, the influence of the ambient temperature is small, and the temperature of the permanent magnet is estimated more accurately. Is possible.

  In the temperature estimation device, the voltage detection unit detects a peak value and a frequency in a voltage waveform applied to the detection coil, and the calculation unit detects the permanent magnet based on the peak value and the frequency. It is preferable to calculate the magnetic flux density.

  In this aspect, the magnetic flux density of the permanent magnet can be calculated based on the peak value and frequency in the voltage waveform. Here, the “peak value” can be replaced with an effective value, and the “frequency” can be replaced with a period.

  In the temperature estimation device, the voltage detection unit detects the peak value and the frequency a plurality of times, and the calculation unit calculates an average value or maximum value of the peak value and an average value or maximum value of the frequency, respectively. In addition, it is preferable to calculate the magnetic flux density of the permanent magnet using the average value or the maximum value.

  In this aspect, the magnetic flux density of the permanent magnet is calculated using the average value or maximum value of the crest value and the frequency. Therefore, for example, when the inverter is electrically connected to the detection coil, the error of the peak value and the frequency accompanying the change in the impedance of the inverter can be reduced.

  In the temperature estimation device, a delivery member capable of delivering power to and from the detection coil, a connection state in which the delivery member and the detection coil are electrically connected, and the delivery member as the detection coil A switching member capable of switching between a disconnected state and a disconnected state, wherein the voltage detection unit is configured to output a voltage applied to the detection coil in a state where the switching member is switched to the disconnected state. It is preferable to detect.

  In this aspect, the voltage applied to the detection coil in a state where the delivery member is disconnected from the detection coil by the switching member is detected. Therefore, the voltage generated in the detection coil can be detected more accurately regardless of the change in the impedance of the delivery member.

  In the temperature estimation device, the stator has a stator coil capable of generating an electromotive force having a magnitude corresponding to the magnitude of the magnetic flux density of the permanent magnet, and transfers power to and from the stator coil. It is preferable that a possible delivery member is further provided, and the detection coil is electrically disconnected from the delivery member.

  In this aspect, the detection coil is provided independently of the stator coil connected to the delivery member. Therefore, the voltage generated in the detection coil can be detected more accurately regardless of the change in the impedance of the delivery member.

  In the temperature estimation device, it is preferable that the detection coil is electrically connected only to the voltage detection unit.

  In this aspect, since the detection coil is not connected to any part other than the voltage detection unit, the voltage applied to the detection coil can be detected more accurately.

  In the temperature estimation device, the permanent magnet has a protruding portion that protrudes from the stator in the axial direction of the rotation shaft of the rotor, and the detection coil is spaced apart from the stator coil in the axial direction and A shield member is provided between the detection coil and the stator coil so as to oppose the protruding portion of the permanent magnet, and for magnetically blocking between the detection coil and the stator coil. It is preferable that

  In this aspect, the detection coil and the stator coil are magnetically blocked by the shield member. For this reason, the influence of the magnetic field generated in the stator coil on the detection coil can be reduced, and thereby the voltage generated in the detection coil can be detected more accurately.

  In the temperature estimation device, it is preferable that the magnetic flux density specifying unit includes a physical quantity detection unit that is provided in the stator and can detect at least one of the magnetic flux of the permanent magnet, the strength of the magnetic field, and the magnetic flux density. .

  In this aspect, at least one of the magnetic flux of the permanent magnet, the strength of the magnetic field, and the magnetic flux density can be detected. Therefore, the magnetic flux density can be specified based on the detection result, and the temperature of the permanent magnet can be estimated based on the magnetic flux density.

Further, the present invention is a power generation system that generates electric power by utilizing expansion of the working fluid, a fluid supply pump that discharges the working fluid, an evaporator that heats the working fluid supplied from the fluid supply pump, A rotating body that rotates due to expansion of the working fluid guided from the evaporator, an output shaft that rotates integrally with the rotating body, and an electric power generator that is connected to the output shaft and generates electric power in accordance with the rotational drive of the rotating body machine and a condenser for condensing the working fluid being subjected to the rotation of the rotating body, the rotating body, the output shaft, and a receiving container to receive the generator, the temperature estimate the temperature of the generator The generator includes a stator and a rotor that is rotatable with respect to the stator and provided with a permanent magnet, and an introduction for introducing the working fluid into the storage container. And the generator Sandwiching said inlet portion and outlet portion for leading the working fluid with is provided on the opposite side is provided in said temperature estimation apparatus, a magnetic flux density identifying means for identifying the magnetic flux density of the permanent magnet, the A storage unit for storing a reference magnetic flux density specified by the magnetic flux density specifying means under a condition in which the temperature of the permanent magnet is known; a specific magnetic flux density specified by the magnetic flux density specifying means; and the known temperature; Based on the reference magnetic flux density, a temperature estimating unit that estimates the temperature of the permanent magnet at the time of specifying the specific magnetic flux density, and a target temperature at which the permanent magnet is preset based on the estimated temperature of the permanent magnet; composed way, the fluid supply pump, and a the evaporator, the command unit for commanding at least one of the condenser, to provide a power generation system.

  According to the present invention, as described above, the temperature of the permanent magnet can be estimated based on the known temperature, the reference magnetic flux density, and the specific magnetic flux density. Therefore, compared with the prior art that requires information on the strength of the magnetic field of the magnetizing element over the entire temperature range assumed for the permanent magnet, the required amount of information (known temperature and reference magnetic flux density) is reduced in advance. Can be reduced.

  Further, in the present invention, the rotating body, the output shaft, and the power generation difference are stored in the storage container, and the introduction part and the lead-out part are provided on both sides of the storage container with the generator interposed therebetween. Therefore, the working fluid introduced into the storage container via the introduction part is supplied to the rotation of the rotating body, flows around the generator, and is led out of the storage container from the lead-out part. That is, according to the present invention, the working fluid can be used not only for rotating the rotating body but also for cooling the generator.

  In the present invention, the temperature estimation device estimates the temperature of the permanent magnet and outputs a command to maintain the permanent magnet at the target temperature based on the estimated temperature. Therefore, compared with the case where the permanent magnet is cooled more than necessary to a sufficiently low temperature where demagnetization does not occur, the power generation capability of the generator can be improved.

Further, the present invention provides a temperature estimation method for estimating the temperature of the permanent magnet using the temperature estimation device for a motor having a stator and a rotor that is rotatable with respect to the stator and provided with a permanent magnet. In the method, the ambient temperature is measured by the ambient temperature detection unit under a condition in which the ambient temperature and the temperature of the permanent magnet are substantially equal, and the reference magnetic flux density of the permanent magnet is measured by the magnetic flux density specifying unit. a preparation step of identifying, after said preparing step, a specifying step of specifying a specific magnetic flux density of the permanent magnet by the magnetic flux density identifying means, a specific magnetic flux density specified in the specifying step, measured by the preparation step and the ambient temperature, which is, and a estimation step of estimating the temperature of the permanent magnet by the temperature estimating section based on the reference magnetic flux density specified by the preparation step, To provide a degree estimation method.

  According to the present invention, as described above, the temperature of the permanent magnet can be estimated based on the known temperature, the reference magnetic flux density, and the specific magnetic flux density. Therefore, compared with the prior art that requires information on the magnetic field strength of the magnetizing element over the entire temperature range assumed for the permanent magnet, the amount of information required (the known temperature prepared in the preparation step). And the reference magnetic flux density) can be reduced.

  According to the present invention, it is possible to reduce the amount of information necessary in advance for estimating the temperature of the permanent magnet.

1 is a schematic diagram illustrating an overall configuration of a power generation system according to an embodiment of the present invention. It is sectional drawing which shows the specific structure of the sealed generator of FIG. It is sectional drawing which expands and shows the generator of FIG. FIG. 4 is a sectional view taken along line IV-IV in FIG. 3. It is a block diagram which shows the electric constitution of the electric power generation system of FIG. It is a flowchart which shows the process performed by the control part of FIG. It is a flowchart which shows the initial setting process of FIG. It is a voltage waveform diagram for demonstrating the physical quantity detected by the voltage detection part of FIG. FIG. 6 is a view corresponding to FIG. 5 showing another embodiment. It is a flowchart which shows the process performed by the control part of FIG. FIG. 4 is a view corresponding to FIG. 3 showing another embodiment.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic diagram illustrating an overall configuration of a power generation system according to an embodiment of the present invention.

  Referring to FIG. 1, a power generation system 1 is guided by a fluid supply pump 2 that discharges a working fluid, an evaporator 3 that heats the working fluid supplied from the fluid supply pump 2, and the evaporator 3. A closed generator 4 that generates power by expansion of the working fluid, a condenser 5 that cools and condenses the working fluid derived from the closed generator 4, and cools the working fluid condensed in the condenser 5. The subcooler 6, the bypass valve 7 for guiding the working fluid from the subcooler 6 to the evaporator 3 without going through the fluid supply pump 2, and the electric power generated by the sealed generator 4 are supplied. And an inverter 21 (see FIG. 5) and a control unit 23 (see FIG. 5) for controlling the fluid supply pump 2, the evaporator 3, the condenser 5, and the subcooler 6.

  More specifically, the power generation system 1 includes a first supply pipe L1 that connects the fluid supply pump 2 and the hermetic generator 4, and a first outlet pipe L2 that connects the hermetic generator 4 and the fluid supply pump 2. The working fluid is circulated through these pipes L1 and L2. The evaporator 3 is provided in the middle of the first supply pipe L1, and the condenser 5 and the subcooler 6 are provided in the middle of the first outlet pipe L2.

  The fluid supply pump 2 discharges a working fluid such as chlorofluorocarbon. The working fluid discharged from the fluid supply pump 2 is guided to the evaporator 3 via the first supply pipe L1.

  The evaporator 3 heats and evaporates the working fluid guided through the first supply pipe L1. Specifically, the evaporator 3 according to the present embodiment includes a flow path for circulating the heating medium, an evaporating warmer 3a (see FIG. 5) capable of raising the temperature of the heating medium flowing through the flow path, and the flow. And an evaporation regulator 3b (see FIG. 5) capable of adjusting the flow rate of the heating medium flowing through the passage. The working fluid is heated by exchanging heat with a relatively low temperature (90 ° C. to 100 ° C.) heating medium flowing in the flow path. As the heating medium, for example, hot water, steam, heated air, exhaust gas, or the like discharged from a manufacturing facility or the like can be used.

  The hermetic generator 4 is a generator connected to the output shaft 10b of the screw turbine 10a by rotating the screw turbines (rotors) 10a and 10a according to the expansion of the working fluid heated by the evaporator 3. 11 is operated to generate electricity. Note that the screw turbines 10a and 10a are cylindrical members each having a spiral protrusion formed on the outer peripheral surface thereof. And the flow path is formed between the outer peripheral surfaces of each screw turbine 10a, 10a and between each protrusion by meshing the protrusions of screw turbine 10a, 10a mutually. The cross-sectional area of the flow path formed between the screw turbines 10a and 10a is set so as to increase from one end side to the other end side (left side to right side in FIG. 2) of each screw turbine 10a and 10a. ing. Hereinafter, a specific configuration of the hermetic generator 4 will be described.

  FIG. 2 is a cross-sectional view showing a specific configuration of the hermetic generator of FIG.

  1 and 2, the hermetic generator 4 includes a rotating member 10 that rotates due to expansion of the working fluid, a generator 11 that generates electric power according to the rotation of the rotating member 10, and the rotating member 10 and A storage container 12 that stores the generator 11, and an ambient temperature detection unit 22 that is provided in the storage container 12 and can detect a temperature around the generator 11 (for example, a temperature of a stator 11 a of the generator 11 described later). (See FIG. 5).

  The rotary member 10 includes the screw turbines 10a and 10a and an output shaft 10b fixed to one of the screw turbines 10a and 10a. The cross-sectional area of the flow path formed between the screw turbines 10a and 10a is set so as to increase from the left to the right in FIG. The output shaft 10b rotates integrally with one screw turbine 10a.

  The generator 11 includes a cylindrical stator 11a fixed to a storage container 12 to be described later, and a rotor 11b provided inside the stator 11a and rotatable with respect to the stator 11a. The rotor 11b is connected to the output shaft 10b of the rotating member 10 and rotates integrally with the output shaft 10b. Hereinafter, the specific structure of the generator 11 is demonstrated with reference to FIG.3 and FIG.4.

  The stator 11a has a cylindrical stator main body 11c fixed to the storage container 12, and a plurality of stator coils 11d held by the stator main body 11c. The stator coils 11d are arranged in the axial direction of the rotating shaft 11e of the rotor 11b as shown in FIG. 3 and arranged around the axis of the rotating shaft 11e as shown in FIG. Each stator coil 11d is electrically connected to an inverter 21 (see FIG. 5) in order to supply generated power. In the present embodiment, the inverter 21 corresponds to a delivery member capable of delivering power to and from the stator coil 11d.

  The rotor 11b includes a rotor body 11f provided in the stator 11a, a rotating shaft 11e that connects the rotor body 11f and the output shaft of the rotating member 10, and a plurality of permanent magnets held by the rotor body 11f. 11g. Each permanent magnet 11g extends along the axis of the rotating shaft 11e as shown in FIG. 3, and is arranged side by side on the same circumference around the axis of the rotating shaft 11e as shown in FIG.

  Referring to FIG. 2, the storage container 12 collectively stores the rotating member 10, a bearing portion J <b> 1, which will be described later, and the generator 11 arranged in order from the left in FIG. 2. The working fluid is introduced into the storage container 12 through the introduction pipe 19a provided at the left end of the storage container 12 in FIG. 2, and the working fluid of the storage container 12 through the outlet 17c provided on the right side of FIG. Derived outside. Since the generator 11 is provided between the introduction pipe 19a and the outlet 17c, the generator 11 is cooled by the working fluid introduced through the introduction pipe 19a.

  Specifically, the storage container 12 includes a holding member 16 that holds the screw turbines 10 a and 10 a, a cylindrical member 14 that extends to the left from the holding member 16, and a lid provided at the left end of the cylindrical member 14. A member 15 and a bottomed member 17 extending rightward from the holding member 16 are provided.

  The holding member 16 includes a main body portion 16a, a bearing member 16b attached to the left side of the main body portion 16a, an extending portion 16c extending to the right side from the main body portion 16a, and a flange formed at the right end of the extending portion 16c. Part 16h. The main body 16a has a storage hole 16d for storing the screw turbines 10a and 10a, an introduction port 16e for introducing a working fluid into the screw turbines 10a and 10a stored in the storage hole 16d, A lead-out port (first lead-out port) 16f for leading out the working fluid guided by the screw turbines 10a and 10a stored in the storage hole 16d, and a bearing part for supporting the output shaft 10b of the screw turbine 10a J1 is provided. The storage hole 16d is a hole that penetrates the main body 16a in the left-right direction. The introduction port 16e is provided at the left end of the main body portion 16a, and communicates with the storage hole 16d and opens to the left side. The lead-out port 16f is provided at the right end of the main body portion 16a, and communicates with the storage hole 16d and opens to the right side. The bearing portion J1 is provided at an inner position of the storage hole 16d on the right side of each screw turbine 10a, and rotatably supports the output shaft 10b of the screw turbine 10a. Thus, in this embodiment, since the bearing part J1 is accommodated in the storage container 12, the working fluid can be confined in the storage container 12 without making the bearing part J1 airtight. In the present embodiment, a portion of the main body portion 16a that stores the screw turbines 10a and 10a constitutes a storage portion, and a portion of the main body portion 16a that surrounds the storage portion constitutes a part of the storage container.

  The bearing member 16b is a member surrounding the periphery of the left end of the output shaft 10b of the screw turbine 10a. A bearing portion J2 that rotatably supports the left end of the output shaft 10b of the screw turbine 10a is provided inside the bearing member 16b. The extending part 16c is formed in a cylindrical shape surrounding the periphery of the output shaft 10b extending to the right side from the main body part 16a.

  The cylindrical member 14 includes a cylindrical main body 14a that extends to the left of the bearing member 16b, and a mounting portion 14b provided at the right end of the cylindrical main body 14a. The attachment portion 14b is for attaching the cylindrical main body 14a to the main body portion 16a of the holding member 16 in a manner that hinders gas flow.

  The lid member 15 forms a turbine chamber S1 on the left side of the holding member 16 in cooperation with the cylindrical member 14 by sealing the opening on the left side of the cylindrical main body 14a of the cylindrical member 14. That is, the turbine chamber S1 is a chamber that is provided between the holding member 16, the cylindrical member 14, and the lid member 15 and stores the screw turbines 10a and 10a. Specifically, the lid member 15 forms a closing plate 18 attached to the opening end of the cylindrical main body 14a, and a flow path from the outside of the closing plate 18 to the inlets of the screw turbines 10a and 10a. A flow path forming member 19 and a filter 20 provided in the flow path formed by the flow path forming member 19 are provided. The closing plate 18 is a disk-like member attached to the cylindrical main body 14a so as to close the opening of the cylindrical main body 14a. A hole penetrating the front and back is formed at a substantially central position of the closing plate 18. The flow path forming member 19 includes an introduction pipe 19a extending to the right side from the closing plate 18, a disc part 19b protruding from the right end of the introduction pipe 19a toward the outer side in the circumferential direction, and a peripheral edge of the disc part 19b. A side plate portion 19c extending to the left side from the portion and a guide tube 19d extending to the right side from the disc portion 19b are provided. The introduction pipe 19a constitutes a flow path of the working fluid from the left side (outside) of the closing plate 18 to the right side of the disc part 19b. Specifically, the lumen portion of the introduction tube 19a penetrates the closing plate 18 and the disc portion 19b. The disc part 19b has a diameter dimension smaller than the inner diameter of the cylindrical body 14a so that a gap is formed between the disk part 19b and the inner surface of the cylindrical body 14a. Therefore, a flow path of the working fluid in the left-right direction (front and back direction) straddling the disc portion 19b is formed between the outer side surface of the disc portion 19b and the inner side surface of the cylindrical main body 14a. The guide pipe 19d constitutes a flow path of the working fluid from the left side of the disc portion 19b to the inlet 16e for the screw turbines 10a and 10a. Specifically, the lumen portion of the guide tube 19d penetrates the disc portion 19b, and the right end portion of the guide tube 19d allows the working fluid to be introduced into the introduction port 16e. It is attached to the left end surface of the main body portion 16a. Therefore, the flow path forming member 19 leads from the left side (outside) of the closing plate 18 to the right side of the disc portion 19b and from the right side of the disc portion 19b to the left side, as indicated by an arrow Y1 in FIG. A flow path is formed from the left side of the disc portion 19b to the introduction port 16e. The filter 20 is provided at a position on the left side of the disc portion 19b and a position between the disc portion 19b (side plate portion 19c) and the cylindrical main body 14a so as to intersect the flow path indicated by the arrow Y1. Yes.

  In this embodiment, the 1st supply piping L1, the cylindrical member 14, and the cover member 15 comprise the piping for expansion | swelling which connects the fluid supply pump 2 and the main-body part (storage part) 16a via the evaporator 3. FIG. .

  The bottomed member 17 includes a bottomed member main body 17a fixed to the right side of the extending portion 16c of the holding member 16, and a filter 17d provided at the bottom of the bottomed member main body 17a. The bottomed member main body 17a seals the opening on the right side of the extended portion 16c, thereby forming the power generation chamber S2 on the right side of the main body portion 16a in cooperation with the extended portion 16c. That is, the power generation chamber S2 is provided between the main body portion 16a, the extension portion 16c, and the bottomed member main body 17a, and is a chamber for housing the generator 11. Specifically, the bottomed member main body 17a is provided with a flange portion 17b fixed to the extending portion 16c, a lead-out port 17c penetrating the bottom portion, and a concave groove 17e formed inside. The flange portion 17b is attached to the extension portion 16c in a state of being in close contact with the right end surface of the extension portion 16c so as to prevent the gas flow. The outlet 17c is for leading the working fluid, and the outlet 17c is provided with a filter 17d. The concave groove 17e is for forming a gap between the stator 11a of the generator 11 and the inner side surface of the bottomed member main body 17a. Specifically, the concave grooves 17e are provided at a plurality of locations so that the inner surface of the bottomed member main body 17a is intermittently depressed in the circumferential direction, and each concave groove 17e is formed on the stator 11a of the generator 11. The bottomed member body 17a is not held in contact with the inner surface of the bottomed member body 17a. Therefore, the gap between each concave groove 17e and the stator 11a functions as a flow path for the working fluid as indicated by an arrow Y3. Further, the gap G between the stator 11a and the rotor 11b of the generator 11 also functions as a working fluid flow path as indicated by an arrow Y2. As the working fluid flows as indicated by the arrows Y2 and Y3, the generator 11 is cooled. And the hydraulic fluid which flowed through the flow path shown by these arrows Y2 and Y3 is derived | led-out from the outlet 17c via the filter 17d, as shown by the arrow Y4.

  Hereinafter, the operation of the power generation system 1 will be described with reference to FIGS. 1 and 2.

  The working fluid discharged from the fluid supply pump 2 is heated in the evaporator 3 and guided to the sealed generator 4 via the first supply pipe L1. This working fluid is introduced into the sealed generator 4 through the introduction pipe 19a, and is guided to the introduction ports 16e of the screw turbines 10a and 10a through the filter 20, as indicated by an arrow Y1. Since the working fluid introduced into the flow path between the screw turbines 10a and 10a tends to expand by heating in the evaporator 3, the screw turbines 10a and 10a are rotated in the direction of expanding the flow path. Proceed to the right in FIG. The working fluid derived from the flow path between the screw turbines 10a and 10a flows while contacting the generator 11 as indicated by arrows Y2 and Y3, and is derived from the outlet 17c. The working fluid flowing as shown by these arrows Y2 and Y3 contacts the generator 11 and contributes to cooling of the generator 11. Note that the flow rate and temperature of the working fluid introduced into the hermetic generator 4 are adjusted by the fluid supply pump 2, the evaporator 3, the condenser 5, and the subcooler 6. Specifically, the control unit 23 described later performs feedback control of the fluid supply pump 2, the evaporator 3, the condenser 5, and the subcooler 6 so that the generator 11 has a predetermined target temperature.

  As shown by the arrow Y4, the working fluid led out from the hermetic generator 4 is led to the condenser 5 and the subcooler 6 through the first lead-out pipe L2. The condenser 5 is capable of adjusting the flow rate of the cooling water flowing through the flow channel, the condenser cooler 5a (see FIG. 5) capable of cooling the cooling water flowing through the flow channel, and the flow rate of the cooling water flowing through the flow channel. And a condensing regulator 5b (see FIG. 5). In the condenser 5, the working fluid is cooled by exchanging heat with, for example, about 0 to 40 ° C. cooling water flowing in the flow path. The supercooler 6 includes a flow path for circulating the cooling water, a supercooling cooler 6a (see FIG. 5) capable of cooling the cooling water flowing through the flow path, and a flow rate of the cooling water flowing through the flow path. And a supercooling regulator 6b (see FIG. 5). In the subcooler 6, the working fluid is cooled by exchanging heat with, for example, cooling water of about 0 to 40 ° C. flowing in the flow path. Then, the working fluid cooled by the condenser 5 and the subcooler 6 is guided to the fluid supply pump 2 and again used for power generation as described above.

  Next, the control unit 23 for controlling the temperature of the generator 11 will be described with reference to FIG.

  The control unit 23 includes a voltage detection unit 24 that detects a voltage applied to the stator coil 11d, a calculation unit 25 that performs calculation processing based on the detection result of the voltage detection unit 24, and a calculation result of the calculation unit 25. , A temperature estimation unit 27 for estimating the temperature of the permanent magnet 11g based on the calculation result of the calculation unit 25 and the information stored in the storage unit 26, and the temperature estimated by the temperature estimation unit 27 And a command unit 28 that outputs commands to the fluid supply pump 2, the evaporator 3, the condenser 5, and the subcooler 6.

  The voltage detector 24 can detect the voltage applied to the stator coil 11d. Specifically, the voltage detection unit 24 detects a peak value Vm and a frequency f in an AC voltage waveform generated in the stator coil 11d, as shown in FIG. Since the peak value Vm can be calculated from the effective value, the voltage detection unit 24 may detect the effective value. In addition, since the frequency f can be calculated from the period, the voltage detection unit 24 may detect the period. When a multiphase AC voltage is applied to the stator coil 11d, the voltage detector 24 can detect the peak value Vm and the frequency f for at least a phase other than one phase.

  The calculator 25 calculates the magnetic flux density of the permanent magnet 11g based on the voltage detected by the voltage detector 24. Specifically, the calculation unit 25 calculates the magnetic flux density of the permanent magnet 11g based on the following formula (2).

B = k × Vm ÷ f (2)
Here, B is the magnetic flux density of the permanent magnet 11g, and k is a constant specific to the generator 11.

  The storage unit 26 stores the magnetic flux density calculated by the calculation unit 25 and the ambient temperature detected by the ambient temperature detection unit 22. Specifically, the storage unit 26 includes an ambient temperature detection unit under conditions where the ambient temperature and the temperature of the permanent magnet 11g are substantially equal (for example, when the generator is started for the first time or when restarting after a long-term stop). The ambient temperature detected by 22 and the magnetic flux density calculated based on the peak value Vm and the frequency f detected by the voltage detector 24 under this ambient temperature condition are stored.

  The temperature estimation unit 27 is a permanent magnet based on the ambient temperature and magnetic flux density stored in the storage unit 26 and the magnetic flux density calculated based on the peak value Vm and the frequency f detected by the voltage detection unit 24. Estimate a temperature of 11 g. Specifically, the temperature of the permanent magnet 11g is estimated based on the following formula (1).

T1 = T0−1 / m × (1−B1 / B0) (1)
Here, T0 is the ambient temperature stored in the storage unit 26, and the magnetic flux density calculated under this ambient temperature condition is B0. B1 is the magnetic flux density calculated based on the peak value Vm and the frequency f detected by the voltage detection unit 24. Note that m is a coefficient defined by the material of the permanent magnet 11g. The estimated temperature T1 is calculated from this equation (1).

  The command unit 28 is configured to provide at least the fluid supply pump 2, the evaporator 3, the condenser 5, and the subcooler 6 so that the permanent magnet 11 g has a preset temperature based on the temperature estimated by the temperature estimation unit 27. A flow control command is output for one. That is, when the estimated temperature is higher than the preset temperature, the command unit 28 outputs a command for increasing the flow rate of the working fluid to the fluid supply pump 2 and / or decreases the temperature of the working fluid. The command can be output to the evaporation temperature riser 3a, the evaporation regulator 3b, the condenser cooler 5a, the condenser regulator 5b, the supercooling cooler 6a, and the supercooling regulator 6b. On the other hand, when the estimated temperature is lower than the preset temperature, the command unit 28 outputs a command for reducing the flow rate of the working fluid to the fluid supply pump 2 and / or increases the temperature of the working fluid. The command can be output to the evaporation temperature riser 3a, the evaporation regulator 3b, the condenser cooler 5a, the condenser regulator 5b, the supercooling cooler 6a, and the supercooling regulator 6b. When the estimated temperature is within a preset temperature (temperature range), the command unit 28 sends a command for maintaining the flow rate of the working fluid to the fluid supply pump 2, the evaporator 3, the condenser 5, and the supercooling. Output to at least one of the devices 6 (or do not output a command to change the flow rate of the working fluid).

  Hereinafter, processing executed by the control unit 23 will be described with reference to FIGS. 6 and 7.

  When the process by the control unit 23 is started, an initial setting process T (preparation process) is executed. In the initial setting process T, first, the ambient temperature T0 is detected under the condition that the ambient temperature of the generator 11 and the temperature of the permanent magnet are substantially equal (step T1). Next, the voltage (crest value Vm and frequency f) applied to the stator coil 11d is detected (step T2), and it is determined whether or not the voltage has been detected a preset number of times N (step T3).

  If it is determined in step T3 that the number is less than N, step T2 is repeatedly executed. On the other hand, if it is determined in step T3 that the number of times is N, an average value of detection results (peak value Vm and frequency f) is calculated (step T4). By calculating the average value of the detection results in this way, errors in the detection value can be reduced even when the impedance of the inverter 21 (see FIG. 5) varies. In step T4, the maximum value of detection results may be calculated.

  Next, the magnetic flux density B0 is calculated by substituting the calculated average values (the crest value Vm and the frequency f) into the above-described equation (2). That is, this magnetic flux density B0 is a magnetic flux density under the condition that the temperature of the permanent magnet 11g is the ambient temperature T0 detected in step T1. Then, the ambient temperature T0 and the magnetic flux density B0 are stored in the storage unit 26 (step T6), and the process returns to the main routine of FIG.

  In the main routine, the voltage (crest value Vm and frequency f) currently applied to the stator coil 11d is detected (step S1), and the voltage is detected for a preset number of times (the same number as the step T3) N. It is determined whether or not (step S2).

  If it is determined in step S2 that the number is less than N, step S1 is repeatedly executed. On the other hand, if it is determined in step S2 that the number of times is N, an average value of detection results (crest value Vm and frequency f) is calculated (step S3). By calculating the average value of the detection results in this way, errors in the detection value can be reduced even when the impedance of the inverter 21 (see FIG. 5) varies. In step S3, the maximum detection result may be calculated.

  Next, the magnetic flux density B1 is calculated by substituting the calculated average values (the crest value Vm and the frequency f) into the above-described equation (2) (step S4: specific step). That is, this magnetic flux density B1 is a magnetic flux density under conditions where the temperature of the permanent magnet 11g is unknown. Then, the estimated temperature T1 is calculated by substituting the magnetic flux density B1, the magnetic flux density B0, and the ambient temperature T0 into the above-described equation (1) (step S5: estimation step).

  Next, a temperature control command is output based on the estimated temperature T1 (step S6). Specifically, when the estimated temperature T1 is higher than a preset temperature, a command for increasing the flow rate of the working fluid is output to the fluid supply pump 2 and / or the temperature of the working fluid is decreased. The command is output to at least one of the evaporator 3, the condenser 5, and the subcooler 6. On the other hand, when the estimated temperature T1 is lower than a preset temperature, a command to reduce the flow rate of the working fluid is output to the fluid supply pump 2, and / or a command to increase the temperature of the working fluid is issued. Output to at least one of the evaporator 3, the condenser 5, and the subcooler 6. In addition, when the estimated temperature T1 is at a preset temperature (or within a temperature range), a command for maintaining the flow rate of the working fluid is output (or a command for changing the flow rate is not output).

  Thus, by performing feedback control of the temperature of the permanent magnet 11g, a result superior to the power generation system according to the following comparative example was obtained. Specifically, in the power generation system according to the comparative example, the temperature of the working fluid and the temperature of the working fluid are set so that the permanent magnet is cooled to a sufficiently low temperature to prevent the occurrence of demagnetization without estimating the temperature of the permanent magnet. The pressure was controlled (the permanent magnet was cooled more than necessary). Specifically, in the power generation system according to the comparative example, the temperature of the working fluid between the evaporator 3 and the closed generator 4 is 80 ° C., and the pressure is 0.8 MPaA. On the other hand, in the power generation system 1 according to the present embodiment, as a result of the feedback control, the temperature of the working fluid between the evaporator 3 and the sealed generator 4 can be increased to 100 ° C. and the pressure can be increased to 1.2 MPaA. . In both the comparative example and the present embodiment, the temperature of the working fluid between the sealed generator 4 and the condenser 5 is 50 ° C., and the pressure is 0.2 MPaA. As can be seen from this result, in the power generation system 1 according to the present embodiment, the temperature and pressure of the working fluid introduced into the hermetic generator 4 can be increased as compared with the comparative example, so that the power generation capacity can be improved. .

  The processes from step S1 to S6 are repeatedly executed until a stop command for the power generation system 1 is input via an operation unit (not shown) (until NO is determined in step S7). When the stop command is input (YES in step S7), the process ends.

  In the power generation system 1, the screw turbines 10a and 10a, the output shaft 10b, and the bearing portion J1 are stored in a common storage container 12. Therefore, the working fluid used for rotation of the screw turbines 10a and 10a can be confined in the storage container 12 without securing the airtightness between the main body portion 16a and the output shaft 10b by the bearing portion J1. Therefore, according to the said electric power generation system 1, compared with the conventional bearing part, simplification of a structure and improvement of durability can be aimed at.

  In the above-described embodiment, the screw turbines 10a and 10a are illustrated as rotors that rotate in response to the expansion of the working fluid. However, the present invention is not limited to this, and for example, a radial turbine may be employed.

  In the above embodiment, the screw turbines 10a, 10a, the main body 16a for storing them, the output shaft 10b, the bearing portion J1, and the storage container 12 for collectively storing the generator 11 have been described, but at least the output shaft 10b. Each of the screw turbines 10a, 10a, and 10b without having to secure airtightness between the main body portion 16a and the output shaft 10b by the bearing portion J1 by having a storage container for housing the bearing portion J1 and the generator 11. The working fluid subjected to the rotation of 10a can be confined in the storage container.

  As described above, in the embodiment, the control unit that controls at least one of the fluid supply pump 2, the evaporator 3, the condenser 5, and the supercooler 6 so that the permanent magnet 11g has a preset temperature. 23. Therefore, a reduction in power generation capacity can be suppressed by preventing demagnetization accompanying the temperature increase of the permanent magnet 11g.

  Specifically, in the generator 11, when the temperature of the rotor 11 b exceeds a predetermined temperature, a so-called demagnetization decrease occurs in which the magnetic flux density of the permanent magnet 11 g is irreversibly decreased. And if demagnetization of the permanent magnet 11g arises, power generation capability will fall. On the other hand, in the said embodiment, since the temperature of the permanent magnet 11g can be maintained at the preset temperature, demagnetization of the permanent magnet 11g can be prevented.

  In the embodiment, the temperature T1 of the permanent magnet 11g can be estimated based on the known temperature T0, the reference magnetic flux density B0, and the specific magnetic flux density B1. Therefore, the amount of information (T0, B0, and B1) prepared in advance can be reduced as compared with the case where information such as a map indicating the relationship between temperature and magnetic flux density is held.

  In the said embodiment, it has the stator coil 11d, the voltage detection part 24, and the calculating part 25. FIG. Therefore, the magnetic flux density of the permanent magnet 11g can be calculated based on the voltage applied to the stator coil 11d.

  In the embodiment, the magnetic flux density of the permanent magnet can be calculated based on the peak value Vm and the frequency f in the voltage waveform.

  Here, in the said embodiment, in order to detect the electromotive force (voltage) which changes according to the magnitude | size of the magnetic flux density of the permanent magnet 11g, compared with a prior art (Unexamined-Japanese-Patent No. 2004-222387), a permanent magnet The response (speed of following) of the estimated temperature change to the temperature change can be improved. Specifically, in the prior art, since the strength of the magnetic field of the magnetizing element that has taken heat from the permanent magnet is detected, the time required for heat transfer from the permanent magnet to the magnetizing element becomes a factor that reduces the responsiveness. . On the other hand, in the said embodiment, since the temperature is estimated based on the electromotive force which arises according to the magnetic flux density of the permanent magnet 11g, without going through heat transfer, the said responsiveness can be improved. Furthermore, in the prior art, the temperature of the magnetizing element varies not with the permanent magnet but with the surrounding temperature, and the estimated temperature of the permanent magnet may become inaccurate. On the other hand, in the embodiment, since the temperature of the permanent magnet 11g is estimated based on the electromotive force corresponding to the magnetic flux density of the permanent magnet 11g, the influence of the ambient temperature is small, and the temperature of the permanent magnet 11g is more accurate. Can be estimated.

  In the embodiment, the magnetic flux density of the permanent magnet 11g is calculated using the average value or the maximum value of the crest value Vm and the frequency f. Therefore, even if the impedance of the inverter 21 electrically connected to the stator coil 11d changes, the error of the peak value Vm and the frequency f is alleviated.

  In the above embodiment, the voltage applied to the stator coil 11d is detected in a state where the stator coil 11d and the inverter 21 are electrically connected, but the present invention is not limited to this. For example, the voltage applied to the stator coil 11d can be detected in a state where the stator coil 11d and the inverter 21 are disconnected.

  FIG. 9 is a view corresponding to FIG. 5 showing another embodiment. In the following description, the same components as those in FIG. 5 are denoted by the same reference numerals and description thereof is omitted.

  The power generation system according to this embodiment includes a contactor 29 provided between the stator coil 11d and the inverter 21, a contactor control unit 31 provided in the control unit 23 and controlling the drive of the contactor 29, and the generator And a rotational position detector 30 that detects the rotational position of the eleventh rotor 11b.

  The contactor 29 can be switched between a connected state in which the inverter 21 and the stator coil 11d are electrically connected and a disconnected state in which the inverter 21 is disconnected from the stator coil 11d.

  The contactor control unit 31 controls the drive of the contactor 29 between the connected state and the disconnected state. Specifically, the contactor control unit 31 switches the contactor 29 to the disconnected state before the voltage detection unit 24 detects the voltage. Further, the contactor control unit 31 connects the stator coil 11d and the inverter 21 when the rotor 11b reaches the target rotation position based on the rotation position of the rotor 11b detected by the rotation position detection unit 30. Then, the contactor 29 is switched to the connected state. Thereby, before and after switching of the contactor 29, the phase of the voltage applied to the inverter 21 and the rotational position (phase) of the rotor 11b can be matched.

  Hereinafter, with reference to FIG. 10, processing executed by the control unit 23 illustrated in FIG. 9 will be described.

  When the process by the control unit 23 is started, after performing the initial setting process T, the contactor 29 is switched to a disconnected state (step S01). Next, after performing steps S1 and S2 described above to detect a voltage, the rotational position detection unit 30 detects the rotational position of the rotor 11b (step S21). Next, based on this rotational position, the contactor 29 is switched to the connected state at the timing when the rotational position of the rotor 11b matches the phase of the voltage applied to the inverter 21 (step S22), and the process proceeds to the above-described step S3. To do.

  In the present embodiment, the voltage can be detected in a state where the stator coil 11 d is disconnected from the inverter 21 by the contactor 29. Therefore, the voltage applied to the stator coil 11d can be accurately detected regardless of the change in the impedance of the inverter 21.

  In this embodiment, since the influence of the impedance of the inverter 21 can be avoided by the contactor 29 as described above, steps S2 and S3 for calculating the average value of the voltage can be omitted.

  In the present embodiment, the step S01 is inserted between the steps T1 and T2 of the initial setting process shown in FIG. 7, and the steps S21 and S22 are inserted between the steps T3 and S5. You can also Thereby, also in the initial setting process, the voltage applied to the stator coil 11d can be accurately detected regardless of the change in the impedance of the inverter 21. Also in this initial setting process, step T3 and step T4 for calculating the average value of the voltage can be omitted.

  In the above-described embodiment, the stator coil 11d of the generator 11 is used as a detection coil for detecting an electromotive force (voltage) applied to the permanent magnet 11g. However, the present invention is not limited to this. For example, a voltage detection coil can be provided separately from the stator coil 11 d of the generator 11. Hereinafter, this embodiment will be described with reference to FIG.

  In the generator 11 according to the present embodiment, the rotor 11b is longer than the stator 11a in the axial direction of the rotating shaft 11e. Specifically, the permanent magnet 11g (rotor 11b) has a protruding portion 11h that protrudes from the stator 11a in the axial direction of the rotating shaft 11e.

  The generator 11 according to the present embodiment includes a detection coil 33 disposed so as to face the protruding portion 11h of the permanent magnet 11g, and the axis of the rotation shaft 11e among the detection coil 33 and each stator coil 11d. And a shield member 32 provided between the stator coil 11d disposed at the end of the direction. The detection coil 33 is disposed away from the stator coil 11d in the axial direction of the rotating shaft 11e. Further, the detection coil 33 is electrically connected to the voltage detection unit 24 (see FIGS. 5 and 9) without being connected to the inverter 21 (see FIGS. 5 and 9). On the other hand, each stator coil 11 d is electrically connected to the inverter 21 without being connected to the voltage detection unit 24. The shield member 32 magnetically blocks between the detection coil 33 and each stator coil 11d.

  In the embodiment, the detection coil 33 is provided independently of the stator coil 11 d connected to the inverter 21. Therefore, the voltage applied to the detection coil 33 can be detected more accurately regardless of the change in the impedance of the inverter 21. If the detection coil 33 is connected only to the voltage detector 24, the voltage applied to the detection coil can be detected more accurately.

  In the embodiment, the detection coil 33 and the stator coil 11d are magnetically cut off by the shield member 32. Therefore, it is possible to reduce the influence of the magnetic field generated in the stator coil 11d on the stator coil 11d. Thereby, the voltage applied to the detection coil 33 can be detected more accurately.

  In the embodiment described above, the magnetic flux density of the permanent magnet 11g is calculated by detecting the voltage applied to the coils 11d and 33. However, the present invention is not limited to this. For example, a physical quantity detection means capable of detecting at least one of the magnetic flux of the permanent magnet 11g, the strength of the magnetic field, and the magnetic flux density can be provided. Thereby, the magnetic flux density can be specified based on the detection result of the physical quantity detection means, and the temperature of the permanent magnet 11g can be estimated based on the magnetic flux density. Even in this case, it is preferable to provide means capable of specifying the frequency of the voltage applied to the stator coil 11d.

  Moreover, although the said embodiment demonstrated the point which estimates the temperature of the permanent magnet 11g about the generator 11 which produces electric power according to rotation of the screw turbines 10a and 10a, the object which estimates temperature is not limited to the generator 11. FIG. Specifically, the temperature of the permanent magnet can also be estimated for a motor whose rotor rotates according to the power supplied from the power source, as in the above embodiment.

B0 Reference magnetic flux density B1 Specific magnetic flux density T0 Ambient temperature (known temperature)
T1 Estimated temperature Vm Crest value f Frequency 1 Power generation system 2 Fluid supply pump 3 Evaporator 4 Enclosed generator 5 Condenser 6 Subcooler 10a Screw turbine (rotating part)
10b Output shaft 11 Generator (an example of a motor)
11a Stator 11b Rotor 11c Stator body 11d Stator coil 11f Rotor body 11g Permanent magnet 11h Protruding part 12 Storage container 21 Inverter (delivery member)
DESCRIPTION OF SYMBOLS 22 Ambient temperature detection part 24 Voltage detection part 25 Operation part 26 Storage part 27 Temperature estimation part 28 Command part 29 Contactor (switching member)
32 Shield member 33 Detection coil

Claims (12)

A temperature estimation device for estimating a temperature of the permanent magnet for a motor having a stator and a rotor that is rotatable with respect to the stator and provided with a permanent magnet,
Magnetic flux density specifying means for specifying the magnetic flux density of the permanent magnet;
A storage unit for storing a reference magnetic flux density specified by the magnetic flux density specifying unit under a condition in which the temperature of the permanent magnet is known;
A temperature estimation unit that estimates the temperature of the permanent magnet at the time of specifying the specific magnetic flux density based on the specific magnetic flux density specified by the magnetic flux density specifying means, the known temperature, and the reference magnetic flux density ;
An ambient temperature detector provided on the stator and detecting an ambient temperature of the stator;
The said memory | storage part is a temperature estimation apparatus which memorize | stores the temperature detected by the said ambient temperature detection part .   The temperature estimation device according to claim 1, wherein the temperature estimation unit estimates a temperature of the permanent magnet based on a ratio of the reference magnetic flux density to the specific magnetic flux density and the known temperature.   The magnetic flux density specifying means is applied to the detection coil provided in the stator and capable of generating an electromotive force having a magnitude corresponding to the magnitude of the magnetic flux density of the permanent magnet, and the detection coil The temperature estimation apparatus according to claim 1, further comprising: a voltage detection unit capable of detecting a voltage; and a calculation unit that calculates a magnetic flux density of the permanent magnet based on the voltage detected by the voltage detection unit. . The voltage detection unit detects a peak value and a frequency in a voltage waveform applied to the detection coil,
The temperature estimation device according to claim 3, wherein the calculation unit calculates a magnetic flux density of the permanent magnet based on the peak value and the frequency. The voltage detection unit detects the peak value and the frequency multiple times,
The arithmetic unit calculates an average value or maximum value of the peak values and an average value or maximum value of the frequency, respectively, and calculates the magnetic flux density of the permanent magnet using these average values or maximum values. 4. The temperature estimation device according to 4. A delivery member capable of delivering power to and from the detection coil;
A switching member capable of switching between a connection state in which the delivery member and the detection coil are electrically connected and a cut state in which the delivery member is separated from the detection coil;
The temperature estimation device according to any one of claims 3 to 5, wherein the voltage detection unit detects a voltage applied to the detection coil in a state where the switching member is switched to the cut state. The stator has a stator coil capable of generating an electromotive force having a magnitude corresponding to the magnitude of the magnetic flux density of the permanent magnet,
A delivery member capable of delivering power to and from the stator coil;
The temperature estimation device according to claim 3, wherein the detection coil is electrically disconnected from the delivery member.   The temperature estimation apparatus according to claim 7, wherein the detection coil is electrically connected only to the voltage detection unit. The permanent magnet has a protruding portion protruding from the stator in the axial direction of the rotation shaft of the rotor,
The detection coil is disposed so as to be spaced apart from the stator coil in the axial direction and to face the protruding portion of the permanent magnet,
The temperature according to claim 7 or 8, wherein a shield member for magnetically blocking between the detection coil and the stator coil is provided between the detection coil and the stator coil. Estimating device. The said magnetic flux density specific | specification means is provided in the said stator, and contains the physical quantity detection part which can detect at least 1 of the magnetic flux of the said permanent magnet, the magnetic field strength, and a magnetic flux density. Temperature estimation device. A power generation system that generates electricity using expansion of a working fluid,
A fluid supply pump for discharging the working fluid;
An evaporator for heating the working fluid supplied from the fluid supply pump;
A rotating body that rotates by expansion of the working fluid guided from the evaporator;
An output shaft that rotates integrally with the rotating body;
A generator connected to the output shaft and generating electric power according to the rotational drive of the rotating body;
A condenser for condensing the working fluid provided for rotation of the rotating body;
A storage container for storing the rotating body, the output shaft, and the generator;
A temperature estimation device for estimating the temperature of the generator,
The generator includes a stator and a rotor that is rotatable with respect to the stator and provided with a permanent magnet.
The storage container is provided with an introduction portion for introducing the working fluid, and a lead-out portion for deriving the working fluid while being provided on the opposite side of the introduction portion with the generator interposed therebetween,
The temperature estimation device includes:
Magnetic flux density specifying means for specifying the magnetic flux density of the permanent magnet;
A storage unit for storing a reference magnetic flux density specified by the magnetic flux density specifying unit under a condition in which the temperature of the permanent magnet is known;
A temperature estimation unit that estimates the temperature of the permanent magnet at the time of specifying the specific magnetic flux density based on the specific magnetic flux density specified by the magnetic flux density specifying means, the known temperature, and the reference magnetic flux density;
A power generation unit including a command unit that commands at least one of the fluid supply pump, the evaporator, and the condenser so that the permanent magnet has a preset target temperature based on the estimated temperature of the permanent magnet. system. About the motor which has a stator and the rotor which can be rotated with respect to this stator and was provided with the permanent magnet, the temperature of the said permanent magnet is measured using the temperature estimation apparatus in any one of Claims 1-10. A temperature estimation method for estimating,
A preparatory step of measuring the ambient temperature by the ambient temperature detection unit and identifying the reference magnetic flux density of the permanent magnet by the magnetic flux density identifying means under the condition that the ambient temperature and the temperature of the permanent magnet are substantially equal. When,
After the preparation step, a specific step of specifying a specific magnetic flux density of the permanent magnet by the magnetic flux density specifying means,
The temperature estimation unit estimates the temperature of the permanent magnet based on the specific magnetic flux density specified in the specific process, the ambient temperature measured in the preparation process, and the reference magnetic flux density specified in the preparation process. A temperature estimation method including an estimation step.

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