JP6397296B2 - Temperature control apparatus and temperature control method - Google Patents

Description

  In the present invention, even when on / off control of alternating current for a plurality of heat sources is performed using a plurality of SSRs (solid state relays), the temperature control of the controlled object is performed with a simple configuration and fine control. The present invention relates to a temperature control device and a temperature control method that can be performed with high accuracy.

  Conventionally, there is a temperature control device that controls the temperature of a fluid to be controlled by turning on and off a heat source by turning on and off the SSR. This temperature control device controls the ratio between the ON period and the OFF period of the alternating current cycle within a certain control period.

  In Patent Document 1, when performing temperature control using a plurality of heat sources, continuous control for continuously supplying heat to one heat source is performed, and on / off control is performed for other heat sources. Yes. By performing this continuous control, the temperature control accuracy can be improved.

Japanese Patent Laid-Open No. 7-20949 JP-A-8-76902 Japanese Utility Model Publication No. 5-43732.

  As described above, in order to realize highly accurate temperature control, continuous control that continuously generates heat is effective instead of on / off control. Therefore, it is preferable to perform continuous control on all heat sources. However, when continuous control is performed on all heat sources, there is a problem that the number of parts increases and the apparatus becomes large.

  Therefore, in order to achieve downsizing of the apparatus, it is conceivable to control a plurality of heat sources using the SSR described above. However, when on / off control is performed using a plurality of SSRs with respect to a plurality of heat sources using an AC power source, the plurality of heat sources are simultaneously turned on. In this case, an inrush current is generated. When the inrush current is generated, the temperature control device needs to be a device having a specification capable of withstanding the inrush current, and the capacity of the electric component needs to be increased.

  For this reason, in Patent Documents 1 and 2, when SSR ON commands for a plurality of heat sources are simultaneously generated, the ON commands are sequentially shifted in time to suppress power concentration due to simultaneous SSR ON.

  However, since the devices described in Patent Documents 1 and 2 are complicated and presuppose that a single-phase AC power supply is used, it is difficult to easily perform fine temperature control of AC current. It is.

  The present invention has been made in view of the above. Even when on / off control of alternating current for a plurality of heat sources is performed using a plurality of SSRs, fine control is performed with a simple configuration. It is an object of the present invention to provide a temperature control device and a temperature control method that can perform temperature control of a controlled object with high accuracy.

  In order to solve the above-described problems and achieve the object, a temperature control device according to the present invention is configured such that a plurality of heat sources are connected to a three-phase AC power source via SSRs respectively, A temperature control device that performs temperature control of a control target by performing energization control, detects at least the temperature of the control target, and calculates a control operation amount for each heat source so that the detected temperature becomes a target temperature When the control operation amount input to the operation amount calculation unit and each SSR corresponding to each heat source is greater than or equal to a predetermined value, an open / close control signal is output as an ON signal, and the control operation amount exceeds the predetermined value. If there is a surplus, the remaining operation amount is set as a carry-over operation amount, and an open / close signal output control unit that adds the carry-over operation amount to the control operation amount at the next control timing, and based on the open / close control signal Within one period of the three-phase output, characterized in that and a distributed output controller for distributed printing by shifting the opening and closing control signal to each SSR split time it was 6 dividing the one period as a unit.

  In the temperature control device according to the present invention, in the above invention, when the distributed output control unit controls the opening / closing of each SSR based on the input switching control signal, at least one of the three-phase outputs. A predetermined one-phase output is input as a reference phase output, and the switching control signal to each SSR is shifted in units of a division time obtained by dividing the one cycle into six within one cycle from the zero-cross timing of the reference phase output. It is characterized by doing.

  In the temperature control device according to the present invention as set forth in the invention described above, the distributed output control unit sets the division time to a time obtained by dividing one known cycle of a commercial power source into six, and 1 of the three-phase output. Within the period, the open / close control signal to each SSR is shifted and output in a dispersed manner with the division time as a unit.

  In the temperature control device according to the present invention as set forth in the invention described above, the open / close control signal is an on / off signal in units of one cycle length.

  Further, the temperature control device according to the present invention is provided between the operation amount calculation unit and the open / close signal output control unit in the above-described invention, and is set in advance so that the initial operation amount for each heat source is different. An initial distributed output control unit that outputs a command operation amount obtained by adding the initial operation amount to the control operation amount output from the operation amount calculation unit to the open / close signal output control unit at the control timing of To do.

  In the temperature control device according to the present invention as set forth in the invention described above, the initial operation amount is a different negative value including zero.

  In the temperature control device according to the present invention as set forth in the invention described above, the SSR is a semiconductor switch including a triac.

  Further, in the temperature control method according to the present invention, a plurality of heat sources are respectively connected to a three-phase AC power source via the SSR, and the temperature control of the controlled object is performed by performing energization control to the heat source by opening / closing control of the plurality of SSRs. A temperature control method to be performed, wherein at least a temperature of the control target is detected, an operation amount calculation step for calculating a control operation amount for each heat source so that the detected temperature becomes a target temperature, and each of the heat sources corresponding to each heat source When the control operation amount input to the SSR is greater than or equal to a predetermined value, an opening / closing control signal is output as an ON signal, and when the control operation amount exceeds a predetermined value, the remaining operation amount is set as a carry-over operation amount. An open / close signal output control step for setting and adding the carry-over operation amount to the control operation amount at the next control timing, and within one cycle of the three-phase output based on the open / close control signal, Characterized in that it comprises a and a distributed printing control step for distributed printing by shifting the opening and closing control signal to each SSR 6 divided split time period as a unit.

  Further, in the temperature control method according to the present invention, in the above invention, the initial operation amount for each heat source is set in advance, and the control operation amount calculated in the operation amount calculation step is set to the control operation amount at the first control timing. An initial distributed output control step of outputting a command operation amount obtained by adding the initial operation amount to the opening / closing signal output control step is provided.

  According to the present invention, when the control operation amount calculated by the operation amount calculation unit is greater than or equal to a predetermined value for each SSR corresponding to each heat source, the open / close signal output control unit uses the SSR open / close control signal as an ON signal. Output, when the control operation amount exceeds a predetermined value, the remaining operation amount is set as a carry-over operation amount, and the carry-over operation amount is added to the control operation amount at the next control timing, and a distributed output control unit However, based on the opening / closing control signal, the opening / closing control signal to each SSR is shifted and output in units of a division time obtained by dividing the period into 6 within one period of the three-phase output. Thereby, even when the on / off control of the alternating current for the plurality of heat sources is performed using the plurality of SSRs, the temperature control of the fluid to be controlled can be performed with high accuracy with a simple configuration by performing fine control. it can.

FIG. 1 is a block diagram showing a configuration of a temperature control apparatus according to Embodiment 1 of the present invention. FIG. 2 is a flowchart showing a distributed output control processing procedure by the distributed output control unit shown in FIG. FIG. 3 is a time chart showing an example of the relationship between the open / close control signal and the total power amount during the distributed output control process by the distributed output control unit shown in FIG. FIG. 4 is a time chart showing an example of the relationship between the open / close control signal and the current flowing through the heat source during the distributed output control process by the distributed output control unit shown in FIG. FIG. 5 is a diagram illustrating an example of the relationship between the number of heat sources and the dispersion time allocated to each heat source. FIG. 6 is a block diagram showing a configuration of a temperature control apparatus according to Embodiment 2 of the present invention. FIG. 7 is a flowchart showing an initial distributed output control processing procedure by the initial distributed output control unit shown in FIG. FIG. 8 is a flowchart showing an open / close signal output control processing procedure by the open / close signal output control unit shown in FIG. FIG. 9 is a flowchart showing an output control processing procedure by the output control unit shown in FIG. FIG. 10 is a diagram illustrating an example of the relationship between the number of heat sources and the initial operation amount assigned to each heat source. FIG. 11 is a time chart showing an example of the relationship between the open / close control signal and the current flowing through the heat source during the initial dispersion output control process by the initial dispersion output control unit shown in FIG. FIG. 12 is a block diagram showing a configuration of a temperature control apparatus according to Embodiment 3 of the present invention. FIG. 13 is a flowchart showing a distributed output control processing procedure by the controller shown in FIG. FIG. 14 is a time chart showing an example of the relationship between the open / close control signal and the current flowing through the heat source during the distributed output control process by the controller shown in FIG. FIG. 15 is a block diagram showing a configuration of a temperature control apparatus which is a modification of the third embodiment of the present invention. FIG. 16 is a diagram illustrating an example of the dispersion time set in the distributed output control unit illustrated in FIG. 15 and the initial operation amount set in the initial distributed output control unit. FIG. 17 is a time chart showing an example of the relationship between the open / close control signal and the current flowing through the heat source during the distributed output control process when the dispersion time and the initial manipulated variable shown in FIG. 15 are set.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings.

(Embodiment 1)
[overall structure]
FIG. 1 is a block diagram showing a configuration of a temperature control apparatus according to Embodiment 1 of the present invention. As shown in FIG. 1, this temperature control device is a pure water heating device that uses pure water W that flows in as a temperature control target fluid. This temperature control device controls on / off of a plurality of heat sources 11-16 such as halogen lamps, supplies heat from the heat sources 11-16 to pure water W, and controls the temperature of the pure water W to a target temperature SV for output. It is. The pure water W passes through the bottles 21 to 26 that form regions to which heat is supplied from the heat sources 11 to 16. The bottles 21 to 26 are sequentially connected. When the pure water W passes through the bottles 21 to 26, the temperature of the pure water W is controlled by receiving heat from the heat sources 11 to 16 sequentially under the control of the controller C.

  The three-phase power source 7 is connected to the plurality of heat sources 11 to 16 through the plurality of SSRs 1 to 6, respectively. The power supply from the three-phase power source 7 to the heat sources 11 to 16 is controlled by switching of the SSRs 1 to 6, respectively.

  As for SSR1-6, the input side (controller C side) and the output side (heat sources 11-16 side) are insulated. The input side and the output side of the SSRs 1 to 6 are optically connected by a phototriac coupler or the like. On the output side of the SSRs 1 to 6, a semiconductor switch such as a triac is provided that connects each phase of the three-phase power source 7 by switching. When the open / close control signal DB, which is an on / off signal, is input to the input side of the SSRs 1 to 6, the open / close control signal DB is sent to the output side of the SSRs 1 to 6 via the phototriac coupler. When the open / close control signal DB is on at the alternating current zero cross point, the output side triac conducts the alternating current and maintains this conducting state until the next zero cross point. The triac has a latch function that maintains the continuity of the alternating current when the switching control signal DB is on at the next zero cross point, and interrupts the continuity of the alternating current when the switching control signal DB is off at the next zero cross point. Have.

  On the other hand, the controller C includes an operation amount calculation unit 30, an opening / closing signal output unit 50, and a distributed output control unit 60. In the operation amount calculation unit 30, the target temperature SV, the inlet temperature PVin detected by the temperature sensor S1 arranged on the inlet side of the most upstream bottle 26, and the outlet side of the most downstream bottle 21 are arranged. The outlet temperature PVout detected by the temperature sensor S0 and the flow rate F of pure water W sent from the flow rate sensor 31 are input. The operation amount calculation unit 30 estimates the outlet temperatures of the bottles 22 to 26 based on the inlet temperature PVin, the outlet temperature PVout, and the heat capacity of the pure water W in the bottles 21 to 26 in consideration of the flow rate F. A control operation amount MV for setting the temperature of the pure water W output from the bottles 21 to 26 to the target temperature SV is calculated and output to the open / close signal output control unit 50. This control operation amount MV is indicated by a value of 0 to 100%. Further, the control operation amount MV is calculated for each of the heat sources 11-16.

  When the control operation amount MV input to each of the SSRs 1 to 6 corresponding to each of the heat sources 11 to 16 is equal to or greater than a predetermined value (for example, 100%), the open / close signal output control unit 50 sets the open / close control signal DA as an ON signal. When SSR1 to SSR6 are output and the control operation amount MV exceeds the predetermined value, the remaining operation amount is set as the carry-over operation amount, and the carry-over operation amount is added to the control operation amount MV at the next control timing. To do. Note that the open / close signal output control unit 50 turns off the open / close control signal DA as an initial state, and when the input control operation amount MV is less than a predetermined value (for example, 100%), the open / close control signal DA Turn DA off.

  When the distributed output control unit 60 outputs the open / close control signal DA output from the open / close signal output control unit 50 to each of the SSRs 1 to 6, a predetermined one-phase output (R phase) of the three-phase outputs of the three-phase power supply 7. Is input as a reference phase output, and the switching control signal DA is shifted with respect to each of the SSRs 1 to 6 in one cycle from the zero-cross timing of the R phase, with the division time obtained by dividing the one cycle into six units, and dispersed in time. An open / close control signal DB is generated and output.

[Distributed output control processing]
Here, the distributed output control processing procedure by the distributed output control unit 60 will be described with reference to the flowchart shown in FIG. The distributed output control unit 60 outputs an opening / closing control signal DB for controlling the heat sources 11 to 16 to the heat sources 11 to 16. Here, the distributed output control processing procedure for the heat source 12 will be described.

  The distributed output control unit 60 first acquires the allocation number N (step S101). This assigned number N is a number corresponding to the sequential position of the zero cross assigned to each of the heat sources 11-16. The assigned numbers N for the heat sources 11 to 16 are 0 to 5, respectively. Therefore, the assigned number N for the heat source 12 is one. As will be described later, the assigned number N is a value of 0 to 5 even if the number of heat sources 11 to 16 increases or decreases. This is because in the three-phase output, there are six zero crosses in one cycle, and therefore there are a maximum of six types of dispersion time with the above-described division time as a unit.

  Thereafter, the dispersion time ΔT is calculated based on the number N of assignments (step S102). The dispersion time ΔT is a value obtained by multiplying one cycle by (N / 6). Accordingly, the dispersion time ΔT with respect to the heat source 12 is 20 msec (when the frequency of the three-phase power supply 7 is 50 Hz), which is 20 × (1/6) msec.

  Thereafter, the distributed output control unit 60 detects a zero-cross of one cycle of the reference phase (R phase) of the three-phase power source 7 (step S103). Further, the distributed output control unit 60 determines whether or not the dispersion time ΔT has elapsed (step S104). That is, the distributed output control unit 60 determines whether or not the elapsed time from the R-phase zero crossing detection point has reached the dispersion time ΔT. In step S103, one cycle of zero cross is detected because there are two zero crosses in the R phase within one cycle.

  When the dispersion time ΔT has not elapsed (step S104, No), the dispersion output control unit 60 repeats this determination process. On the other hand, when the dispersion time ΔT has elapsed (step S104, Yes), the dispersion output control unit 60 outputs the opening / closing control signal DB to the SSRs 1 to 6 for the heat sources 11 to 16 to be controlled (step S105). The process described above is repeated. Here, since there are six dispersion times ΔT at maximum, when there are six heat sources 11 to 16, different dispersion times ΔT can be set for each of the heat sources 11 to 16. The open / close control signal DB is an on / off signal in units of one cycle length.

  In the distributed output control process described above, the open / close control signal DB is generated by shifting the open / close control signal DA input to each of the heat sources 11 to 16 using a different dispersion time ΔT within one cycle. Distributed output in time.

[Example of distributed output control processing]
Here, an example of the distributed output control process will be described with reference to the time charts shown in FIGS. 3 and 4, the control operation amount MV input from the operation amount calculation unit 30 to the six heat sources 11 to 16 continues to be 50% at the same time, and is input from the open / close signal control unit 50. The distributed output control process when the open / close control signal DA to be turned on simultaneously is shown.

  As shown in FIG. 3, the open / close control signals DB (DB1 to DB6) for the heat sources 11 to 16 are sequentially turned on with a time lag from the R-phase zero crossing time t1 (t2 to t6). ). As a result, the total electric energy gradually increases over one cycle, and then all the open / close control signals DB1 to DB6 are turned off with a time delay (t7 to t12), so that the entire power amount gradually increases over one cycle. To decrease.

  FIG. 4 shows current waveforms flowing in the respective power supplies 11 to 16 when the opening / closing control signals DB1 to DB6 shown in FIG. 3 are output. As shown in FIG. 4, the currents flowing through the heat sources 11 to 16 are distributed and output within one cycle, similarly to the switching control signals DB1 to DB6. In particular, in FIG. 4, since the control operation amount is 50%, a flat power distribution is obtained even when the on / off control signals DA1 to DA6 are repeatedly turned on and off at the same time.

  In particular, during steady operation after startup, there are many cases where the amount of operation is low, but by performing this distributed output control processing, even if the on / off control switching signals DA1 to DA6 are used, it is equivalent to continuous control. Processing can be performed. As a result, the temperature difference between the heat sources 11 to 16 at the time of steady operation can be reduced, and finely and precisely controlled temperature control can be realized. That is, in the distributed output control process described above, the open / close control signals DA1 to DA6 are distributed and output within one cycle by utilizing the occurrence of six zero crosses in which the three-phase outputs are temporally dispersed in one cycle. The temperature control of the water W is performed with high accuracy.

  Further, the distributed output control process described above can also be applied at startup. Even at the time of starting, since the power distribution can be made moderate in time within one cycle, the occurrence of inrush current can be suppressed.

  In the first embodiment described above, the six heat sources 11 to 16 are controlled in accordance with the zero cross of one cycle of the three-phase output. However, the number of heat sources is not limited to this. For example, as shown in FIG. 5, 1 to 8 heat sources 11 to 18 can be controlled. However, it is necessary to set appropriately the phase output connected to each heat source 11-18 according to the number of heat sources. For example, as shown in FIG. 5, when the number of heat sources is three, the assigned number N of the heat source 11 is 0, the assigned number N of the heat source 12 is 2, and the assigned number N of the heat source 13 is 4. Further, when the number of heat sources is eight, the heat sources 11 to 16 are set with the same allocation number N and phase output as in the above-described embodiment. On the other hand, although it outputs with respect to the heat sources 17 and 18 overlapping with the other heat sources 11-16, the output of each heat source 17 and 18 is separated and output in time. That is, the allocation number N is set to 1 and 4.

  In the above-described embodiment, the distributed output control unit 60 inputs the R phase of the three-phase power supply 7 to the distributed output control unit 60 and detects the zero cross of the R phase using the R phase as a reference phase. A zero cross may be detected using another S phase or T phase as a reference phase. Further, two-phase zero crosses of the three phases may be detected, or zero crosses of all three phases may be detected. By using such a multi-phase zero cross, the time measurement process of the dispersion time ΔT is reduced.

  The zero cross of the reference phase may not be used. For example, an arbitrary time point is set as a reference zero-cross time point, and a division time obtained by dividing one cycle of a known power supply frequency to be used is obtained from this zero-cross time point. A value obtained by sequentially adding the obtained division times can be used as the dispersion time ΔT. Even when an arbitrary time point is set as a reference zero-crossing time point, the output switching control signals DB1 to DB6 are generated within one division time, and each switching control signal DB1 to DB6 is generated within an overlapping division time. There is nothing. Each of the SSRs 1 to 6 is turned on within less than the divided time from the ON output of the switching control signals DB1 to DB6, and is turned off within less than the divided time from the OFF output of the switching control signals DB1 to DB6. As a result, it is possible to perform the same on / off operations as SSRs 1 to 6 according to the first embodiment described above.

(Embodiment 2)
[overall structure]
Next, a second embodiment of the present invention will be described. In the second embodiment, the occurrence of inrush current at the initial startup of the apparatus is suppressed. For this reason, as shown in FIG. 6, an output control unit 61 is provided instead of the distributed output control unit 60 of the first embodiment, and an initial distributed output control unit 40 is newly provided before the switching signal output control unit 50. ing. Other configurations are the same as those of the first embodiment. In the second embodiment, the R phase of the three-phase power source 7 is input to the output control unit 61. The initial distributed output control unit 40 performs control for each of the heat sources 11 to 16.

[Initial distributed output control processing]
Here, the initial distributed output control processing procedure by the initial distributed output control unit 40 will be described with reference to the flowchart shown in FIG. As shown in FIG. 7, the initial distributed output control unit 40 first determines whether or not it is the first control timing of control start (step S201).

  When it is the first control timing of the control start (step S201, Yes), the initial dispersion output control unit 40 acquires an initial operation amount set in advance for each of the heat sources 11 to 16 (step S202). Note that the initial operation amount of each of the heat sources 11 to 16 is set to a value when the number of heat sources shown in FIG. 10 is six. Specifically, the initial operation amounts for the heat sources 11 to 16 are 0%, − (100% × 1 / number of heat sources = 6), − (100% × 2 / number of heat sources = 6), and − (100%, respectively. × 3 / number of heat sources = 6), − (100% × 4 / number of heat sources = 6), − (100% × 5 / number of heat sources = 6). That is, the initial operation amounts for the heat sources 11 to 16 are 0%, −16.7%, −33.3%, −50.0%, −66.7%, and −83.3%. These initial operation amounts are all set to negative values except when the heat source 11 is zero. Moreover, the negative value of the initial operation amount set to each heat source 11-16 does not become the same value. And by setting the initial operation amount to a negative value, the total power amount for each of the heat sources 11 to 16 can be gradually increased, and the inrush current can be suppressed.

  Thereafter, the initial distributed output control unit 40 calculates the command operation amount OUTMV (step S203), outputs it to the open / close signal output control unit 50, proceeds to step S201, and repeats the above-described processing. The command operation amount OUTMV in step S203 is obtained by adding the control operation amount MV calculated by the operation amount calculation unit 30 to the initial operation amount.

  On the other hand, when the control timing is not the first control start time (No at Step S201), the control operation amount MV is calculated as the command operation amount OUTMV (Step S204), and is output to the open / close signal output control unit 50, Step S201. The process described above is repeated.

[Open / close signal output control processing]
Here, an open / close signal output control processing procedure by the open / close signal output control unit 50 will be described with reference to the flowchart shown in FIG. As shown in FIG. 8, the open / close signal output control unit 50 first calculates an output operation amount (step S301). This output operation amount is calculated by adding the previous carry-over operation amount to the command operation amount OUTMV output by the initial distributed output control unit 40.

  Thereafter, the opening / closing signal output control unit 50 determines whether or not the output operation amount is 100% (predetermined value) or more (step S302). When the output operation amount is 100% or more (step S302, Yes), an instruction to turn on the open / close control signal DA is output to the output control unit 61 (step S303). Then, the opening / closing signal output control unit 50 calculates a carry-over operation amount (step S304), proceeds to step S301, and repeats the above-described processing. In the calculation of the carry-over operation amount in step S304, 100% is subtracted from the output operation amount.

  On the other hand, when the output operation amount is not 100% or more (step S302, No), an instruction to turn off the open / close control signal DA is output to the output control unit 61 (step S305). Then, the open / close signal output control unit 50 calculates a carry-over operation amount (step S306), moves to step S301, and repeats the above-described processing. In the calculation of the carry-over operation amount in step S306, the current output operation amount is used as the carry-over operation amount as it is.

[Output control processing]
Furthermore, the output control processing procedure by the output control unit 61 will be described with reference to the flowchart shown in FIG. As shown in FIG. 9, first, the output control unit 61 detects a zero-cross of one cycle of the reference phase (R phase) of the three-phase power source 7 (step S401). After that, the output control unit 61 outputs the opening / closing control signal DB to the SSRs 1 to 6 for the heat sources 11 to 16 to be controlled in accordance with the detected zero cross of one cycle (step S402), and the process proceeds to step S401 and described above. Repeat the process.

[Example of initial distributed output control processing]
Here, an example of the initial distributed output control process will be described based on the time chart shown in FIG. In the initial distributed output process shown in FIG. 11, the initial manipulated variable is 0 and − (100% / (the number of heat sources = 1 to 5)) for the six heat sources 11 to 16, as shown in FIG. Is set to a negative value. In addition, in FIG. 11, the output control state DB (DB1-DB6) when each control operation amount MV with respect to each heat source 11-16 is 50%, and the output state of the electric current which flows into the heat sources 11-16 at that time are shown. Yes.

  As shown in FIG. 11, at the first control timing t11, none of the heat sources 11 to 16 has reached 100% at 50%, and the initial manipulated variable is zero for the first time at the second control timing t12. The output operation amount of the heat source 11 (SSR1) becomes 100%, and the open / close control signal DB1 is turned on. Thereafter, at the third control timing t13, the output operation amount of the heat sources 12, 13, and 14 (SSRs 2, 3, and 4) becomes 100% or more, and the opening / closing control signals DB2, DB3, and DB4 are turned on for the first time. Further, at the fourth control timing t14, the output operation amount of the heat sources 11, 15, 16 (SSR1, 5, 6) becomes 100% or more, and the open / close control signals DB1, DB5, DB6 are turned on. At subsequent control timings, it is repeated that at each control timing, the three heat sources become 100% or more and the three open / close control signals DB are turned on.

  And each SSR1-6 sends an alternating current to the heat sources 11-16 according to the switching control signals DB1-DB6. Thereby, it is possible to suppress the occurrence of an inrush current at the start-up initial stage.

  In the second embodiment described above, the initial distributed output control process using a three-phase AC power supply is performed. However, this initial distributed output control can be applied whether a single-phase AC power source is used or a DC power source is used.

(Embodiment 3)
[overall structure]
Next, a third embodiment of the present invention will be described. In the third embodiment, the distributed output control process shown in the first embodiment and the initial distributed output control process shown in the second embodiment are combined. That is, as shown in FIG. 12, an initial dispersion output control unit 40 is provided after the manipulated variable calculation unit 30, and an opening / closing signal output control unit 50 is provided after the initial dispersion output control unit 40. A distributed output control unit 60 is provided after the control unit 50. Other configurations are the same as those of the first and second embodiments.

  Similar to the second embodiment, the initial distributed output control unit 40 is set in advance for each of the heat sources 11 to 16 at the control operation amount MV output by the operation amount calculation unit 30 at the first control start control timing. The command operation amount OUTMV obtained by adding the initial operation amount is output to the open / close signal output control unit 50. Then, the initial distributed output control unit 40 outputs the control operation amount MV output by the operation amount calculation unit 30 to the open / close signal output control unit 50 as the command operation amount OUTMV at the second control start control timing.

  The opening / closing signal output control unit 50 adds the command operation amount OUTMV input from the initial distributed output control unit 40 and the previous carry-over operation amount, and when the addition value becomes 100% or more, the opening / closing control signal DA ( DA1 to DA6) are turned on and output to the distributed output control unit 60.

  The distributed output control unit 60 calculates a dispersion time ΔT for each of the heat sources 11 to 16 with a division time obtained by dividing one period into six within one period from the zero-cross timing of the R-phase output of the three-phase power source 7. And the distributed output control part 60 produces | generates the switching control signals DB1-DB6 which shifted the input switching control signals DA1-DA6 in time using the dispersion | distribution time (DELTA) T with respect to each heat source 11-16, and each SSR1-. 6 for distributed output.

[Distributed output control processing by controller]
Here, the distributed output control processing procedure by the controller C will be described with reference to the flowchart shown in FIG. As shown in FIG. 13, first, the initial distributed output control unit 40 first determines whether it is the first control start control timing (step S501).

  When it is the control timing of the first control start (step S501, Yes), the initial dispersion output control unit 40 acquires an initial operation amount set in advance for each of the heat sources 11 to 16 (step S502).

  Thereafter, the initial distributed output control unit 40 calculates the command operation amount OUTMV (step S503), outputs it to the open / close signal output control unit 50, and proceeds to step S505. The command operation amount OUTMV in step S503 is obtained by adding the control operation amount MV calculated by the operation amount calculation unit 30 to the initial operation amount.

  On the other hand, when the control timing is not the first control start timing (step S501, No), the control operation amount MV is calculated as the command operation amount OUTMV (step S504), and is output to the open / close signal output control unit 50, step S505. Migrate to

  Thereafter, in step S505, the opening / closing signal output control unit 50 calculates an output operation amount. This output operation amount is calculated by adding the previous carry-over operation amount to the command operation amount OUTMV output by the initial distributed output control unit 40.

  Thereafter, the open / close signal output control unit 50 determines whether or not the output operation amount is 100% (predetermined value) or more (step S506). When the output operation amount is 100% or more (step S506, Yes), an instruction to turn on / off the control signal DA is output to the distributed output control unit 60 (step S507). Then, the open / close signal output control unit 50 calculates a carry-over operation amount (step S508). In this calculation of the carry-over operation amount in step S508, 100% is subtracted from the output operation amount.

  Thereafter, the distributed output control unit 60 that has received the instruction to turn on the opening / closing control signal first acquires the number N of allocations (step S509). This assigned number N is a number corresponding to the sequential position of the zero cross assigned to each of the heat sources 11-16. The assigned numbers N for the heat sources 11 to 16 are 0 to 5, respectively.

  Thereafter, the distributed output control unit 60 calculates the distribution time ΔT based on the number of allocations N (step S510). The dispersion time ΔT is a value obtained by multiplying one cycle by (N / 6). Accordingly, the dispersion time ΔT with respect to the heat source 12 is 20 msec (when the frequency of the three-phase power supply 7 is 50 Hz), which is 20 × (1/6) msec.

  Thereafter, the distributed output control unit 60 detects a zero-cross of one cycle of the reference phase (R phase) of the three-phase power source 7 (step S511). Further, the distributed output control unit 60 determines whether or not the dispersion time ΔT has elapsed (step S512). That is, the distributed output control unit 60 determines whether or not the elapsed time from the R-phase zero crossing detection point has reached the dispersion time ΔT.

  When the dispersion time ΔT has not elapsed (step S512, No), the dispersion output control unit 60 repeats this determination process. On the other hand, when the dispersion time ΔT has elapsed (step S512, Yes), the dispersion output control unit 60 outputs to the SSRs 1 to 6 the open / close control signal DB that turns on the SSRs 1 to 6 for the heat sources 11 to 16 to be controlled ( Step S513), the process proceeds to step S501 and the above-described processing is repeated.

  On the other hand, when the output operation amount is not 100% or more (step S506, No), the open / close signal output control unit 50 outputs an instruction to turn off the open / close control signal DA to the distributed output control unit 60 (step S514). ). Thereafter, the opening / closing signal output control unit 50 calculates a carry-over operation amount (step S515). In the calculation of the carry-over operation amount in step S515, the current output operation amount is directly used as the carry-over operation amount. Upon receiving the instruction to turn off the open / close control signal DB in step S514, the distributed output control unit 60 outputs the open / close control signal DB that turns off SSR1 to 6 to SSR1 to 6 (step S516), and proceeds to step S401. The above process is repeated.

[Example of distributed output control processing by controller]
FIG. 14 is a time chart showing an example of the distributed output control process by the controller C. The processing shown in FIG. 14 is the result of adding the distributed output control processing by the distributed output control unit 60 to the initial distributed output processing by the initial distributed output control unit 40 as shown in FIG. The operation amount calculation unit 30 is premised on calculating a control operation amount of 50% at each control timing. Further, the initial operation amount shown in FIG. 11 is used as the initial operation amount.

  As shown in FIG. 14, at the first control timing t11, since the initial operation amount is 0 and a negative value, none of the heat sources 11 to 16 has reached 100%, and the second control timing. At t12, the command operation amount OUTMV of the heat source 11 becomes 100% for the first time, and the open / close control signal DA1 is turned on. Since the dispersion time ΔT with respect to the heat source 11 is 0, the opening / closing control signal DA1 is output as it is to the SSR1 as the opening / closing control signal DB1. Thereafter, at the third control timing t13, the command operation amount OUTMV of the heat sources 12, 13, and 14 becomes 100% or more, and the open / close control signals DA2, DA3, and DA4 are turned on for the first time. Then, the distributed output control unit 60 outputs the open / close control signals DA2, DA3, DA4 from the control timing t13 by 20 × (1/6) msec, 20 × (2/6) msec, 20 × (3/6), respectively. The switching control signals DB2, DB3, and DB4 shifted by msec are output to the SSRs 2, 3, and 4. Further, at the fourth control timing t14, the command operation amount OUTMV of the heat sources 11, 15, and 16 becomes 100% or more, and the open / close control signals DA1, DA5, and DA6 are turned on. Then, the distributed output control unit 60 switches the open / close control signals DA1, DA5, DA6 from the control timing t14 by 0 msec, 20 × (4/6) msec, and 20 × (5/6) msec, respectively. , DB5, DB6 are output to SSRs 1, 5, 6. At subsequent control timings, the three heat sources become 100% or more at each control timing, and the three open / close control signals DB output in a distributed manner are turned on.

  In the third embodiment, the occurrence of inrush current at the initial start-up can be further suppressed by the initial distributed output control process, and highly accurate temperature control can be performed during the steady operation by the distributed output control process.

(Modification of Embodiment 3)
In the above-described first to third embodiments, the bottles 21 to 26 are sequentially connected in series, and the temperature of the pure water W is controlled by supplying heat to the heat sources 11 to 16, respectively. In this modification, two systems of the bottles 21 to 23 and the bottles 24 to 26 connected in series are connected in parallel, and the bottles 21 to 26 are respectively supplied with heat to the heat sources 11 to 16 to control the temperature of the pure water W. I am doing so.

  FIG. 15 is a block diagram showing a configuration of a temperature control apparatus which is a modification of the third embodiment. As shown in FIG. 15, the pure water W to be controlled is branched into two on the inlet side, flows into the bottles 21 to 23 and the bottles 24 to 26, respectively, and is combined into one flow path on the outlet side. Is output.

  The operation amount calculation unit 30 of the controller C includes the target temperature SV, the inlet temperatures PVin1 and PVin2 detected by the temperature sensors S1a and S1b arranged on the inlet side of the upstream bottles 23 and 26, and the downstream bottle 21 and The outlet temperature PVout detected by one temperature sensor S0 arranged on the outlet side of 24 and the flow rates F1 and F2 of the pure water W sent from the flow rate sensors 31a and 31b to the bottles 23 and 26 are input. The manipulated variable calculation unit 30 is configured based on the inlet temperatures PVin1, PVin2, the outlet temperature PVout, and the heat capacity of the pure water W in the bottles 21 to 26 in consideration of the flow rates F1, F2. 26 is estimated, a control operation amount MV for setting the temperature of the pure water W output from the bottles 21 to 26 to the target temperature SV is calculated and output to the initial dispersion output control unit 40. Other configurations are the same as those of the third embodiment.

  In the third embodiment described above, the dispersion time ΔT and the initial manipulated variable divided into six are set in the order of connection for one system of the heat sources 11 to 16 corresponding to the bottles 21 to 26 connected in series. . In the modified example of the third embodiment, the heat sources 11 to 13 and the heat sources 14 to 16 corresponding to the bottles 21 to 23 and the bottles 24 to 26 connected in parallel are connected in the order of connection and alternately. In addition, the dispersion time ΔT divided into six and the initial manipulated variable are set.

  For example, as illustrated in FIG. 16, the dispersion time ΔT is set to increase in the order of the heat sources 11, 14, 12, 15, 13, and 16. In addition, as shown in FIG. 16, the initial operation amount is also set to increase the negative value in the order of the heat sources 11, 14, 12, 15, 13, and 16.

  FIG. 17 shows the switching control signal and the current flowing through the heat source during the distributed output control process by the controller C when the dispersion time and the initial operation amount shown in FIG. 16 are set for the temperature control device shown in FIG. It is a time chart which shows an example of these relationships. In this modified example, even when the bottles 21 to 26 and the heat sources 11 to 16 are connected in parallel, heat is supplied alternately to the two systems connected in parallel, so that uniform heat supply is possible and accuracy is improved. High temperature control can be performed.

  This modification can also be applied to the first and second embodiments. Various forms of parallel connection are possible. For example, all may be connected in parallel, or three or more direct connection systems may be three or more parallel connections.

1-6 SSR
7 Three-phase power supply 11-16 Heat source 21-26 Bottle 30 Manipulated variable calculation unit 31, 31a, 31b Flow rate sensor 40 Initial dispersion output control unit 50 Open / close signal output control unit 60 Distributed output control unit 61 Output control unit C Controller DA, DA1 ~ DA6, DB, DB1 ~ DB6 Open / close control signal F, F1, F2 Flow rate MV Control manipulated variable OUTMV Command manipulated variable PVin, PVin1, PVin2 Inlet temperature S0, S1, S1a, S1b Temperature sensor SV Target temperature t1 Zero cross point t11-t14 Control timing W Pure water

Claims (9)

A plurality of heat sources are connected to a three-phase AC power source via SSRs, respectively, and are temperature control devices that perform temperature control of a controlled object by performing energization control to the heat sources by open / close control of the plurality of SSRs,
An operation amount calculation unit that detects at least the temperature of the control target and calculates a control operation amount for each heat source so that the detected temperature becomes a target temperature;
In the same control timing for one cycle of the control period of the three-phase output, when acquiring the control operation amount input for each SSR corresponding to each heat source is obtained control amount is greater than or equal to a predetermined value An opening / closing control signal for controlling opening / closing of the SSR is output as an ON signal, and when the control operation amount is less than the predetermined value, the opening / closing control signal is output as an OFF signal, and the control operation amount exceeds a predetermined value. that case, the said control operation amount is a value obtained by subtracting the predetermined value from the control amount as carry-over operation amount, to Oite obtained following the control timing to output the switching control signal as an on-signal An open / close signal output control unit for adding a carry-over operation amount;
Within one period of the three-phase output, a distributed printing control unit for distributed printing by shifting the opening and closing control signal to each of SSR based on the said control timing in units of divided time was 6 dividing the one period,
A temperature control device comprising: The distributed output control unit inputs at least a predetermined one-phase output of the three-phase outputs as a reference phase output when performing open / close control of each SSR based on the input open / close control signal, and the reference phase 2. The temperature control device according to claim 1, wherein the open / close control signal to each SSR is shifted and output in units of a division time obtained by dividing the one cycle into six within one cycle from the output zero cross timing. . The distributed output control unit, the divided-time period, the known one period of the commercial power supply is set to 6 divided time, within one period of the three-phase output, the opening and closing of each SSR the divided time units The temperature control device according to claim 1, wherein the control signals are output in a distributed manner while being shifted.   The temperature control device according to any one of claims 1 to 3, wherein the open / close control signal is an on / off signal in units of one cycle length.   A control operation provided between the operation amount calculation unit and the open / close signal output control unit, set in advance so that the initial operation amount for each heat source is different, and output from the operation amount calculation unit at the first control timing The temperature control according to any one of claims 1 to 4, further comprising an initial distributed output control unit that outputs a command operation amount obtained by adding the initial operation amount to an amount to the open / close signal output control unit. apparatus.   The temperature control device according to claim 5, wherein the initial operation amount is a different negative value including zero.   The temperature control apparatus according to claim 1, wherein the SSR is a semiconductor switch including a triac. A temperature control method in which a plurality of heat sources are connected to a three-phase AC power source via SSRs respectively, and temperature control of a control target is performed by performing energization control to the heat sources by opening / closing control of the plurality of SSRs,
An operation amount calculation step of detecting at least the temperature of the control target and calculating a control operation amount for each heat source so that the detected temperature becomes a target temperature;
In the same control timing for one cycle of the control period of the three-phase output, when acquiring the control operation amount input for each SSR corresponding to each heat source is obtained control amount is greater than or equal to a predetermined value An opening / closing control signal for controlling opening / closing of the SSR is output as an ON signal, and when the control operation amount is less than the predetermined value, the opening / closing control signal is output as an OFF signal, and the control operation amount exceeds a predetermined value. that case, the said control operation amount is a value obtained by subtracting the predetermined value from the control amount as carry-over operation amount, to Oite obtained following the control timing to output the switching control signal as an on-signal An open / close signal output control step for adding a carry-over operation amount;
Within one period of the three-phase output, a distributed printing control step for distributed printing by shifting the opening and closing control signal to each of SSR based on the said control timing in units of divided time was 6 dividing the one period,
The temperature control method characterized by including.   The initial operation amount for each heat source is set to be different, and at the first control timing, the command operation amount obtained by adding the initial operation amount to the control operation amount calculated in the operation amount calculation step is the opening / closing signal output control step. The temperature control method according to claim 8, further comprising an initial dispersion output control step of outputting to the output.

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