JP2007116812A - Inverter motor test device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an inexpensive and small-sized inverter motor device that can suppress capacities of an AC power supply and a DC power supply. <P>SOLUTION: Two sets of motors 2, 3 are arranged so as to oppose each other, inverter devices 10, 11 are connected to them, respectively, and rotating shafts 4, 5 of the motors 2, 3 are coupled to each other via a power transmission mechanism 6. A DC power supply device 20 that feeds power to the inverter devices 10, 11 has a power supply capacity adequate to the receiving of constant power to the inverter devices 10, 11, and an accumulation device 30 that performs the receiving of transient power is connected to the DC power supply device 20 in parallel therewith. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an inverter / motor test apparatus for testing characteristics of an inverter and a motor.

  In general, an AC motor driven through an inverter device that converts a DC voltage into an AC voltage is used for various applications, and in particular, in recent years, it is often used as a driving power source for hybrid vehicles and electric vehicles. It is like that. Therefore, in order to develop an inexpensive and high-performance motor and inverter device, a test device for performing various characteristic tests such as a maximum output test is required. However, the conventional test device is large, consumes a large amount of power and is expensive. And contributed to the increase in development costs.

  For this reason, for example, in Patent Document 1, the first motor connected to the first inverter and the second motor connected to the second inverter are coupled to each other via a transmission mechanism, and the output of one inverter is obtained. A technique for suppressing power consumption by regenerating with the other inverter is disclosed.

In Patent Document 2, two power converters are used, and one of the power converters is used as a virtual load of the motor, and the operation of the motor is simulated without actually connecting the motor. A technique for testing an inverter is disclosed.
Japanese Patent Laid-Open No. 2003-153546 Japanese Patent Laid-Open No. 2004-88832

  By the way, when testing inverters and motors, transient power increases and decreases, so the DC power supply that supplies DC power to the inverters is in addition to the steady loss consumed by the inverters and motors. There is a problem that transient power supply and absorption must be performed simultaneously.

  Therefore, it is necessary to increase the capacity of the DC power supply so as to have a margin for the loss of the inverter / motor, and a large capacity is required for the AC power supply and the DC power supply generated by converting this AC power supply. Power consumption has increased and the power supply device has to be enlarged, which has been a factor that hinders cost reduction of the entire test apparatus.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an inverter / motor test apparatus capable of reducing the capacity of an AC power source and a DC power source to be an inexpensive and small device.

  In order to achieve the above object, an inverter / motor test apparatus according to the present invention is an inverter in which two motors are installed opposite to each other and their respective rotating shafts are coupled via a power transmission mechanism, and an inverter device is connected to each motor. A motor test apparatus, which is connected to the DC power supply device in parallel with a DC power supply device having a power capacity suitable for the steady power transfer to each inverter device, And a power storage device that performs transmission and reception.

  An inverter / motor test apparatus according to the present invention includes an AC power source connected in parallel to a DC power supply device having a power supply capacity suitable for steady power transfer to the inverter device. In addition, the capacity of the DC power supply can be suppressed, and an apparatus suitable for evaluation of an inverter / motor can be realized as an inexpensive and small-sized apparatus.

  Embodiments of the present invention will be described below with reference to the drawings. 1 to 8 relate to a first embodiment of the present invention, FIG. 1 is a basic configuration diagram of an inverter / motor test apparatus, FIG. 2 is a circuit diagram showing the basic configuration of the inverter apparatus, and FIG. FIG. 4 is a waveform diagram schematically showing the current supplied from the DC power supply, FIG. 5 is a configuration diagram showing a first mounting example of the position detector, and FIG. 6 is a second diagram of the position detector. FIG. 7 is a block diagram showing a third mounting example of the position detector, and FIG. 8 is a block diagram showing a fourth mounting example of the position detector.

  Inverter / motor test apparatus 1 shown in FIG. 1 is an apparatus in which two motors 2 and 3 are installed opposite to each other, and inverter apparatuses 10 and 11 are connected to each other, and an inverter and motor evaluation test is performed. A measuring device such as a vibration meter, a torque meter, and a power meter, and a data processing device are provided, and a measuring system is formed by connecting these devices to each other. In this inverter / motor test apparatus 1, for example, a traveling motor for an electric vehicle or a hybrid vehicle is set, and an inverter device for controlling the traveling motor is set, and the performance / characteristics thereof are evaluated. be able to.

  When the motors 2 and 3 are coupled to each other through a power transmission mechanism 6 such as a joint or a gear mechanism, and either one of the motors and the inverter device performs a power running operation, the other motor and the inverter device Performs a regenerative operation to form a power return system that returns power between the motors. This power recirculation includes a direct current power supply device (DC power supply device) 20 having a power supply capacity commensurate with regular power transfer to the inverter devices 10 and 11 and a power storage device 30 connected in parallel with the DC power supply device 20. Done through. As will be described later, the power storage device 30 functions as an auxiliary power source that transfers and receives transient power.

  The inverter devices 10 and 11 include inverter circuits 10a and 11a that convert DC power into three-phase AC power, and controllers 10b and 11b that control the inverter circuits 10a and 11a, respectively. The inverter circuits 10a and 11a have basically the same configuration. As representatively shown in FIG. 3, the switching elements S1 to S6 are bridge-connected and the DC terminals P and N connected to the DC power supply device 20 are connected. This is a well-known circuit configuration having AC terminals U, V, and W connected to the motor 2 or the motor 3. A capacitor C is connected between the DC terminals P and N.

  Each of the switching elements S1 to S6 is turned on / off by the controllers 10b and 11b, and a three-phase AC output under PWM control is output from the AC terminals U, V, and W. As the switching element, a switching element such as an IGBT, a bipolar transistor, a MOSFET, or a thyristor can be used. In addition, diodes D1 to D6 having a cathode on the DC terminal P side to which a positive voltage is applied are connected in parallel to the switching elements S1 to S6, respectively, for protection against a reverse voltage.

  The inverter devices 10 and 11 can be operated as a converter that converts three-phase AC power into DC power. That is, when a three-phase AC voltage is applied to the AC terminals U, V, and W, they are rectified by the diodes D1 to D6, and a DC output can be obtained from the DC terminals P and N.

  On the other hand, the DC power supply device 20 includes, for example, a rectifier circuit or a chopper circuit that converts an AC voltage supplied from an AC power source 40 such as a commercial power source into a DC voltage, and converts high-voltage and large-capacity DC power into the inverter device 10, 11 is supplied. In addition, the power storage device 30 includes, for example, a secondary battery such as a lead battery, a lithium ion battery, or a nickel metal hydride battery, a capacitor such as an electric double layer capacitor or an electrolytic capacitor, and a combination of a secondary battery and a capacitor. It is configured by using at least one of a battery and a capacitor, and is configured by connecting each battery / capacitor cell module in series and in parallel. FIG. 3 shows an example in which m cells 30a are connected in series to form a module, and k modules are connected in parallel to form the power storage device 30. The number of series / parallel connections is an inverter / motor test. It is set according to conditions and the capacity of the DC power supply device 20.

  When a test is performed using the inverter / motor test apparatus 1 having the above configuration, one of the inverter apparatuses is driven to generate a three-phase AC voltage from the AC terminals U, V, and W.

  For example, when the inverter device 10 on the motor 2 side is driven to generate a three-phase AC voltage and the inverter circuit 10a and the motor 2 are operated in a powering manner, the three-phase AC voltage generated in the inverter circuit 10a is applied to the motor 2. Then, the rotor of the motor 2 rotates. The rotation of the motor 2 is transmitted to the rotation shaft 5 of the motor 3 coupled to the rotation shaft 4 of the motor 2 via the power transmission mechanism 6. As a result, the rotor of the motor 3 also rotates, the motor 3 functions as a generator, and a three-phase AC voltage is output from the motor 3. The three-phase AC voltage output from the motor 3 is applied to AC terminals U, V, and W of the inverter device 11, and the inverter circuit 11a functions as a converter to output DC power from the DC terminals P and N.

  From the inverter device 10, the motors 2, 3 and the inverter device 11 that behave like this appear as loads, so that an output test for the inverter device 10 can be performed, and further, as a converter of the inverter device 11. An operation test can be performed together. Further, the DC power obtained through the inverter device 11 is regenerated by the DC power supply device 20 and the power storage device 30 and can be used again by the inverter device 10.

  At this time, even if transient power increase / decrease occurs during operation, the power storage device 30 connected in parallel to the DC power supply device 20 supplies and absorbs transient power. When a system is configured only from a DC power supply device as in the past, transient power supply / absorption and steady loss supply must be performed simultaneously from the DC power supply device. As schematically shown in a), the current It from the DC power supply device periodically fluctuates greatly. Therefore, conventionally, it has been necessary to increase the capacity of the DC power supply so as to have a margin more than the loss of the inverter / motor.

  On the other hand, in the inverter / motor test apparatus 1 of the present invention, the power storage device 30 is connected in parallel with the DC power supply device 20, and the power storage device 30 performs transient power supply / absorption. As schematically shown in (b), the fluctuation peak can be smoothed to obtain a stabilized average current Is, and the DC power supply 20 can be made compact as a power supply capacity suitable for supplying a steady loss. Can be In this case, the test voltage condition of the inverter / motor is not necessarily constant, but the test voltage condition can be adapted by appropriately setting the number m of cells connected in series in the power storage device 30, and the number k of modules connected in parallel can be reduced. A stable DC voltage can be maintained by appropriately setting.

  That is, in the inverter / motor test apparatus 1 of the present invention, not only the electric power is recirculated between the motors, but also the power storage device 30 shares the transfer of the transient electric power and supplies the stationary electric power from the DC power supply device 20. As a result, a power-saving system that reduces the power consumption of the entire system by circulating power with high efficiency is formed. As a result, the capacity of the AC power source and DC power source required for the system can be suppressed, and the inverter / motor test apparatus 1 can be made inexpensive and small, making it suitable for evaluation of the inverter / motor.

  Furthermore, in a normal inverter / motor evaluation test, control is performed using a position or speed detector attached to the motor, but in recent years, sensorless control of the motor is becoming widespread, and no position or speed detector is provided. It is also necessary to evaluate the motor. In sensorless control of a motor, the influence of the control algorithm is large on the basic performance such as controllability and efficiency of the inverter / motor. Therefore, it is necessary to eliminate the influence of the control algorithm and evaluate the basic performance of the inverter / motor.

  Since the speed detector is basically the same as the position detector, the position detector will be described below as a representative.

  Therefore, when the motors 2 and 3 are sensorless motors, position detectors such as encoders, resolvers, and hall sensors are attached to the motor shaft and the coupling shaft between the motors as shown in FIGS. By performing control using the information of the position detector, it is possible to eliminate the influence of the control algorithm and evaluate the basic performance of the inverter / motor. It is also possible to evaluate a sensorless control algorithm by comparing with a control method in the case of sensorless.

  FIG. 5 shows an example in which position detectors are attached to both the motors 2 and 3. In this example, the position detector 15 attached to the rear end of the rotating shaft 4 of the motor 2 is connected to the controller 10 b of the inverter device 10, and the position detector 16 attached to the rear end of the rotating shaft 5 of the motor 3 is connected to the inverter device 11. Connected to the controller 11b. Thus, even if the inverter devices 10 and 11 are sensorless drive inverter devices that do not have an interface for directly receiving position detection information from the motor, it is possible to receive the position detection information of the motor.

  In addition, it is good also as a structure which installs a converter between a position detector and an inverter apparatus, pre-processes position detection information, and takes in an inverter.

  FIG. 6 shows an example in which a position detector is attached to one of the motors 2 and 3. In FIG. 6, a position detector 17 is attached to the rear end of the rotating shaft 5 of the motor 3. It is connected to the controller 11b of the inverter device 11 that drives the motor 3. The controller 11b of the inverter device 11 is connected to the controller 10b of the inverter device 10 on the motor 2 side via the communication line 18, and information on one position detector 17 is transmitted from the inverter device 11 to the inverter device 10 on the motor 2 side. Is done. Even in such a configuration, similarly, it is possible to receive position detection information even in a sensorless drive inverter device that does not have an interface for directly receiving position detection information.

  As shown in FIG. 7, the position detector 17 on the motor 3 side is connected to both the controller 10 b of the inverter device 10 that drives the motor 3 and the controller 11 b of the inverter device 11 that drives the motor 2. Anyway.

  Further, as shown in FIG. 8, a high-resolution position detector 19 is attached to a coupling shaft obtained by coupling the rotating shaft 4 of the motor 2 and the rotating shaft 5 of the motor 3 to the position detector 17 on the motor 3 side. The signal from the position detector 19 having a high resolution may be preprocessed by the converter 19a to improve the processing speed and may be input to the controller 10b of the inverter device 10. In this case, the same effect can be obtained.

  The position detectors 15, 16, 17, and 19 described above have a structure in which each mounting angle can be freely adjusted so that the position detection reference point can be adjusted according to the structure of the motor. Thereby, the correction amount of the electrical angle calculation of the motor can be easily set in the control software of the inverter.

  Next, a second embodiment of the present invention will be described. FIG. 9 is a basic configuration diagram of an inverter / motor test apparatus according to a second embodiment of the present invention.

  In the second mode, a host controller as a host controller that controls the inverter devices 10 and 11 is provided for the inverter devices 10 and 11 that drive the motors 2 and 3.

  That is, as shown in FIG. 9, in the inverter / motor test apparatus 1A of the second form, the controller 10b of the inverter apparatus 10 and the controller 11b of the inverter apparatus 11 are different from the inverter / motor test apparatus 1 of the first form. A host controller 50 to be connected is provided. From the host controller 50, control commands are given to the lower controllers 10b and 11b, and the states of both the inverter devices 10 and 11 and the motors 2 and 3 are controlled by one host controller 50.

For example, a command to torque the motor 2 is given to the controller 10b of one inverter device 10, and a command to run the motor 3 at a rotational speed is given to the controller 11b of the other inverter device 11 to the controller 11b on the motor 3 side. When a test for gradually increasing the rotational speed command is performed, when the inverter device 10 on the motor 2 side performs general vector control, the voltage command values Vd and q-axis on the d-axis (magnetic flux axis) ( The voltage command value Vq and the line-to-line AC voltage Vac on the torque axis are in a relationship represented by the following equation.
Vac = (Vd ² + Vq ² ) ^1/2

  Here, in the test as described above, the d-axis voltage command value Vd and the q-axis voltage command value Vq to the controller 10b on the inverter device 10 side increase as the motor rotation speed increases. However, if the control parameters in the inverter control are not properly tuned, the inverter control may oscillate and become unstable. In the worst case, the inverter and the motor may be damaged.

  As an indication that the inverter control oscillates, the line AC voltage Vac becomes oscillating. Therefore, the upper controller 50 sets an upper limit value of the line AC voltage Vac and sets the line AC voltage Vac to the upper limit value. When it reaches, the rotational speed command to the controller 11b of the inverter device 11 is lowered to reduce the motor rotational speed, and the oscillation of the inverter control is avoided. As a result, if a problem occurs in one inverter device or motor, the other inverter device or motor can be restricted, and safety can be improved.

  When performing sensorless control of the motor, as in the first embodiment, a position detector is attached to the motor shaft and the coupling shaft between the motors so that the position detection reference point can be adjusted. By performing control using, it is possible to eliminate the influence of the control algorithm and evaluate the basic performance of the inverter / motor.

The basic composition figure of an inverter motor test device concerning a 1st embodiment of the present invention. Same as above, circuit diagram showing basic configuration of inverter device As above, an explanatory diagram showing an internal connection configuration of the power storage device Same as above, waveform diagram schematically showing current supplied from DC power supply Same as above, configuration diagram showing a first mounting example of the position detector Same as above, configuration diagram showing a second mounting example of the position detector Same as above, configuration diagram showing a third mounting example of the position detector The same as above, the block diagram which shows the 4th attachment example of the position detector The basic composition figure of an inverter motor test device concerning a 2nd embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1A Inverter motor test apparatus 2,3 Motor 4,5 Rotating shaft 6 Power transmission mechanism 10,11 Inverter apparatus 15,16,17,19 Position detector 18 Communication line 20 DC power supply apparatus 30 Power storage apparatus 40 AC power supply 50 Host controller (host controller)

Claims (6)

An inverter / motor test apparatus in which two motors are installed opposite to each other and their rotation shafts are coupled via a power transmission mechanism, and an inverter device is connected to each motor,
A direct current power supply device having a power supply capacity commensurate with the steady power transfer to each of the inverter devices;
An inverter / motor testing apparatus, comprising: a power storage device connected in parallel to the DC power supply device and for transferring and receiving transient power to the inverter devices.   2. The inverter / motor test apparatus according to claim 1, wherein the power storage device is configured using at least one of a secondary battery and a capacitor.   The power storage device has a configuration in which a plurality of cells are connected in series and in parallel, and at least one of the number of series connections and the number of parallel connections is set according to test voltage conditions. Inverter motor test equipment.   2. When one of the two motors is a sensorless motor having no position detector, the sensorless motor is controlled using position detection information detected by a position detector of the other motor. The inverter motor test apparatus as described in any one of -3.   When one of the two motors is a sensorless motor not having a position detector, the position detection information of the other motor is communicated from the inverter device controlling the other motor to the inverter device controlling the sensorless motor. The inverter / motor test apparatus according to any one of claims 1 to 3. Provided with a high-order control device for controlling each inverter device by outputting a control command to each inverter device,
The control command for limiting the output of the other inverter device is output when the voltage command value to one inverter device output from the control device exceeds a set value. The inverter / motor test apparatus according to 1.

Images