Parallel power supply, program

Abstract

Each power conversion device (30, 130) included in a parallel power supply device comprises: an individual output voltage sensor (42, 142) that detects an individual output voltage value (VHr); a current sensor (40, 140) that detects a control current value (ILr); and a control device (50). A system to which the parallel power supply device is applied comprises a common output voltage sensor (44) for detecting a common output voltage value (VHext) that is the voltage value between high and low potential-side output paths (12H, 12L). The parallel power supply device is configured so that the detected common output voltage value, an output-voltage command value (VH*) common to the power conversion devices, and an output-power command value (Pext*) common to the power conversion devices are input to each control device. Each control device performs switching control on the basis of the input output-voltage command value, the individual output voltage value, the control current value, the output-power command value, and the common output voltage value.

Description

Cross - reference to related applications

[0001] This application is based on Japanese Application No. 2022 - 210645 filed on December 27, 2022, the contents of which are incorporated herein by reference.

Technical Field

[0002] This disclosure relates to a parallel power supply device and a program.

Background Art

[0003] As this type of parallel power supply device, for example, as described in Patent Document 1, a device including a plurality of DCDC converters connected in parallel is known.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] Due to some factors, the output voltage values of each DCDC converter may be significantly different. In this case, a power imbalance occurs in which the output power values of each DCDC converter are significantly different, and there is a risk that the load will be significantly biased towards some of the DCDC converters.

[0006] The main object of this disclosure is to provide a parallel power supply device and a program that can suppress power imbalance.

[0007] andThis disclosure is applied to a system including a DC power supply and a supply target part of the output power of the DC power supply, and in a parallel power supply device including a plurality of power conversion devices, each of the power conversion devices ​​A DC-DC converter having a switch, a reactor, a high-potential input terminal, a low-potential input terminal, a high-potential output terminal, and a low-potential output terminal, which transforms the DC voltage input from the high-potential input terminal and the low-potential input terminal by repeatedly accumulating magnetic energy in the reactor and releasing magnetic energy from the reactor through switching control of the switch, and outputs the DC voltage from the high-potential output terminal and the low-potential output terminal, An individual output voltage sensor that detects individual output voltage values ​​which are the voltage values ​​between the high-potential side input terminal and the low-potential side input terminal, A current sensor that detects a control current value which is either the current value flowing through the reactor or the current value flowing to the high-potential output terminal, A control device to which the detected individual output voltage value and the control current value are input, Equipped with, The aforementioned system, A high-potential input path is an electrical path that connects the positive terminal of the DC power supply and the high-potential input terminal of each DC-DC converter. A low-potential input path is an electrical path that connects the negative terminal of the DC power supply and the low-potential input terminal of each DC-DC converter. A high-potential output path is an electrical path that connects the high-potential side terminal of the supply target unit and the high-potential side output terminal of each DC-DC converter, The low-potential output path is an electrical path that connects the low-potential terminal of the supply target unit and the low-potential output terminal of each DC-DC converter, A common output voltage sensor that detects a common output voltage value which is the voltage value between the high-potential side output path and the low-potential side output path, Equipped with, The parallel power supply unit is configured such that the detected common output voltage value, the common output voltage command value for each power converter, and the common output power command value for each power converter are input to each control device. Each of the control devices performs switching control of the switches based on the input output voltage command value, the individual output voltage value, the control current value, the output power command value, and the common output voltage value.

[0008] In this disclosure, in order to make the output power value of the DC-DC converters of each power converter a common output power command value, the output voltage value of each DC-DC converter is controlled to a common output voltage command value based on the control current value. However, due to some factor, the output voltage values ​​of each DC-DC converter may differ significantly.

[0009] Here, the common output voltage value detected by the common output voltage sensor is equivalent to the actual output voltage value of each DC-DC converter. Therefore, the common output voltage value serves as a parameter to compensate for variations in the output voltage values ​​of each DC-DC converter.

[0010] In view of this, in this disclosure, the control device of each power converter controls the switching of the DC-DC converter based on the input output voltage command value, individual output voltage values, control current value, and output power command value, as well as a common output voltage value. This makes it possible to suppress power imbalance. [Brief explanation of the drawing]

[0011] The purposes and other purposes, features and benefits of this disclosure will be further clarified by the following detailed description with reference to the attached drawings. Those drawings are: [Figure 1] Figure 1 is an overall configuration diagram of the control system according to the first embodiment. [Figure 2] Figure 2 is a diagram showing the configuration of each power converter that makes up the control system. [Figure 3] Figure 3 is a functional block diagram of the boost control process performed by the ECU. [Figure 4] Figure 4 is a functional block diagram of the processing performed by the voltage correction value calculation unit of the ECU. [Figure 5]FIG. 5 is a functional block diagram of the process performed by the current correction value calculation unit of the ECU, [Figure 6] FIG. 6 is a diagram showing the deviation of the individual output voltage value with respect to the common output voltage value, [Figure 7] FIG. 7 is a diagram showing the deviation of the corrected current value with respect to the reference current value, [Figure 8] FIG. 8 is a diagram showing the relationship between the deviation amount of the corrected current value with respect to the reference current value and the deviation amount of the individual output voltage value with respect to the common output voltage value, [Figure 9] FIG. 9 is a diagram showing the relationship between the deviation amount of the corrected current value with respect to the reference current value and the voltage correction value, [Figure 10] FIG. 10 is a diagram showing the deviation of the reactor current value with respect to the reference current value, [Figure 11] FIG. 11 is a diagram showing the deviation of the corrected output voltage value with respect to the common output voltage value, [Figure 12] FIG. 12 is a diagram showing the relationship between the deviation amount of the corrected output voltage value with respect to the common output voltage value and the deviation amount of the reactor current value with respect to the reference current value, [Figure 13] FIG. 13 is a diagram showing the relationship between the deviation amount of the corrected output voltage value with respect to the common output voltage value and the current correction value, [Figure 14] FIG. 14 is a flowchart showing the procedure of the boost control process, [Figure 15] FIG. 15 is a flowchart showing the procedure of the process of the voltage correction value calculation unit, [Figure 16] FIG. 16 is a flowchart showing the procedure of the process of the current correction value calculation unit, [Figure 17] FIG. 17 is a diagram showing the correction mode of the detected individual output voltage value, [Figure 18] FIG. 18 is a diagram showing the correction mode of the detected reactor current value, [Figure 19] FIG. 19 is a functional block diagram of the process performed by the voltage correction value calculation unit according to the second embodiment, [Figure 20] FIG. 20 is a functional block diagram of the process performed by the current correction value calculation unit, [Figure 21] Figure 21 is a functional block diagram of the processing performed by the voltage correction value calculation unit according to the third embodiment. [Figure 22] Figure 22 is a diagram showing an example of a method for determining whether to allow or restrict the correction process by the voltage correction value calculation unit. [Figure 23] Figure 23 is a functional block diagram of the processing performed by the voltage correction value calculation unit. [Figure 24] Figure 24 is a diagram showing an example of a method for determining whether to allow or restrict the correction process by the current correction value calculation unit. [Figure 25] Figure 25 is a diagram showing an example of a method for determining whether to permit or restrict the correction process by the current correction value calculation unit according to a modified example of the third embodiment. [Figure 26] Figure 26 is a diagram showing the configuration of each power converter that constitutes the control system according to the fourth embodiment. [Figure 27] Figure 27 is a functional block diagram of the boost control process performed by the ECU. [Figure 28] Figure 28 is a functional block diagram of the processing performed by the voltage correction value calculation unit. [Figure 29] Figure 29 is a diagram showing the configuration of each power converter that constitutes the control system according to the fifth embodiment. [Modes for carrying out the invention]

[0012] Multiple embodiments will be described with reference to the drawings. In multiple embodiments, functionally and / or structurally corresponding and / or related parts may be given the same reference numeral, or reference numerals that differ by hundreds or more digits. For corresponding and / or related parts, refer to the descriptions of other embodiments.

[0013] <First Embodiment> The following describes a first embodiment of the parallel power supply device described herein with reference to the drawings. The control system equipped with the parallel power supply device is mounted on a vehicle such as an electric vehicle. However, the mobile object to which the control system is applied is not limited to a vehicle, but may also be, for example, an aircraft, a ship, or a railway vehicle. Furthermore, the target of the control system may also be a robot (e.g., an industrial robot), a generator, an elevator, a stationary emergency power supply, or a stationary charger.

[0014] As shown in Figure 1, the control system comprises a DC power supply 10, an electrical load 20 (corresponding to the "supplied unit"), and a plurality of power converters 30 that transmit power between the DC power supply 10 and the electrical load 20. In this embodiment, the case where there are two power converters 30 will be described as an example. The DC power supply 10 is, for example, a rechargeable battery. The electrical load 20 includes, for example, an inverter and a rotating electric machine. Alternatively, a rechargeable battery may be provided instead of the electrical load 20.

[0015] In this embodiment, the configuration of each power converter 30 is the same. As shown in Figure 2, the power converter 30 is equipped with a boost chopper type DC-DC converter. The DC-DC converter is equipped with a reactor 31, upper and lower arm switches SWH and SWL, a first capacitor 32 and a second capacitor 33. In this embodiment, each switch SWH and SWL is an IGBT. A freewheeling diode is connected in antiparallel to each switch SWH and SWL.

[0016] The first terminal of the reactor 31 is connected to the first terminal of the first capacitor 32 and to the first high-potential side terminal TH1 (corresponding to the "high-potential side input terminal") of the power converter 30. The second terminal of the first capacitor 32 is connected to the first low-potential side terminal TL1 (corresponding to the "low-potential side input terminal") of the power converter 30. The second terminal of the reactor 31 is connected to the emitter, which is the low-potential side terminal of the upper arm switch SWH, and to the collector, which is the high-potential side terminal of the lower arm switch SWL.

[0017] The collector of the upper arm switch SWH is connected to the first terminal of the second capacitor 33 and to the second high-potential side terminal TH2 (corresponding to the "high-potential side output terminal") of the power converter 30. The second terminal of the second capacitor 33 is connected to the second low-potential side terminal TL2 (corresponding to the "low-potential side output terminal") of the power converter 30. The emitter of the lower arm switch SWL is connected to the second low-potential side terminal TL2 and the first low-potential side terminal TL1.

[0018] The power converter 30 includes a current sensor 40, a first voltage sensor 41 (corresponding to an "individual input voltage sensor"), a second voltage sensor 42 (corresponding to an "individual output voltage sensor"), and an ECU 50 as a control device. The current sensor 40 detects the current flowing through the reactor 31. The first voltage sensor 41 detects the terminal voltage of the first capacitor 32, and the second voltage sensor 42 detects the terminal voltage of the second capacitor 33. The detected values ​​of each sensor 40 to 42 are input to the ECU 50.

[0019] The control system includes a first high-potential side path 11H (corresponding to a "high-potential side input path") and a first low-potential side path 11L (corresponding to a "low-potential side input path") as electrical paths for connecting the DC power supply 10 and each power converter 30. The first high-potential side path 11H connects the positive terminal of the DC power supply 10 to the first high-potential side terminal TH1 of the power converter 30. The first low-potential side path 11L connects the negative terminal of the DC power supply 10 to the first low-potential side terminal TL1 of each power converter 30.

[0020] The control system includes a second high-potential side path 12H (corresponding to a "high-potential side output path") and a second low-potential side path 12L (corresponding to a "low-potential side output path") as electrical paths for connecting each power converter 30 to the electrical load 20. The second high-potential side path 12H connects the second high-potential side terminal TH2 of each power converter 30 to the high-potential side terminal of the electrical load 20. The second low-potential side path 12L connects the second low-potential side terminal TL2 of each power converter 30 to the low-potential side terminal of the electrical load 20.

[0021] The first high-potential terminal TH1 of each power converter 30 is connected via the first high-potential path 11H, and the first low-potential terminal TL1 of each power converter 30 is connected via the first low-potential path 11L. In addition, the second high-potential terminal TH2 of each power converter 30 is connected via the second high-potential path 12H, and the second low-potential terminal TL2 of each power converter 30 is connected via the second low-potential path 12L. As a result, the DC-DC converters of each power converter 30 are connected in parallel.

[0022] The control system includes a first common voltage sensor 43 (corresponding to a "common input voltage sensor"), a second common voltage sensor 44 (corresponding to a "common output voltage sensor"), and a VCU 45 which is a higher-level control device for the ECU 50. The first common voltage sensor 43 detects the voltage between the first high-potential path 11H and the first low-potential path 11L. The second common voltage sensor 44 detects the voltage between the second high-potential path 12H and the second low-potential path 12L. In this embodiment, the detected values ​​of each common voltage sensor 43 and 44 are not input to the ECU 50 of each power converter 30, but are input to the VCU 45.

[0023] The VCU45 and the ECU50 of each power converter 30 are primarily composed of a microcontroller, which is equipped with a CPU. The functions provided by the microcontroller can be provided by software recorded in a physical memory device and the computer that executes it, by software only, by hardware only, or by a combination thereof. For example, when the microcontroller is provided by electronic circuits which are hardware, it can be provided by digital circuits including a large number of logic circuits, or by analog circuits. For example, the microcontroller executes a program stored in a non-transitory tangible storage medium which serves as its own memory. The program includes, for example, a program for processing shown in Figures 3-5, 16, etc., described later. When the program installed in the VCU45 and ECU50 is executed, the method corresponding to the program is executed. The memory is, for example, non-volatile memory. The program stored in the memory can be downloaded and updated via a communication network such as the Internet, for example, OTA (Over The Air).

[0024] The VCU 45 acquires a common input voltage value VLext, which is the voltage value detected by the first common voltage sensor 43, and a common output voltage value VHext, which is the voltage value detected by the second common voltage sensor 44. The VCU 45 transmits the acquired common input voltage value VLext and common output voltage value VHext to the ECU 50 of each power converter 30. In this embodiment, the common input voltage value VLext transmitted to each ECU 50 is a common value, and the common output voltage value VHext transmitted to each ECU 50 is a common value.

[0025] The VCU45 transmits the output power command value Pext* and the output voltage command value VH* to the ECU50 of each power converter 30. In this embodiment, the output voltage command value VH transmitted to each ECU50 is a common value.

[0026] The output power command value Pext* is the command value for the output power of the DC-DC converter in the power converter 30. The VCU 45 calculates the output power command value Pext* (=Ptotal / Ncv) by dividing the total power command value Ptotal to be supplied from the DC power supply 10 to the electrical load 20 by the number of Ncv of the power converter 30. Therefore, the output power command value Pext* transmitted to each ECU 50 is a common value.

[0027] In each power converter 30, the ECU 50 receives the common input voltage value VLext, the common output voltage value VHext, the output power command value Pext*, and the output voltage command value VH* transmitted from the VCU 45. In each power converter 30, the reactor current value ILr (corresponding to the "control current value"), which is the current value detected by the current sensor 40, the individual input voltage value VLr, which is the voltage value detected by the first voltage sensor 41, and the individual output voltage value VHr, which is the voltage value detected by the second voltage sensor 42, are input to the ECU 50. In each power converter 30, the ECU 50 performs boost control to increase the output voltage value of the DC-DC converter to the output voltage command value VH*.

[0028] Figure 3 is a functional block diagram of the boost control that is individually executed by the ECU 50 of each power converter 30.

[0029] The voltage control unit 51 calculates the reactor current command value IL*, which is the current command value to flow through the reactor 31, as an manipulated variable for feedback control of the corrected output voltage value VHc output from the voltage summing unit 53 (described later) to the output voltage command value VH*. The feedback control used in the voltage control unit 51 is, for example, proportional-integral control.

[0030] The current control unit 52 calculates the duty cycle D* as an operable variable for feedback control of the corrected current value ILc output from the current summing unit 54 (described later) to the reactor command current value IL*. The feedback control used in the current control unit 52 is, for example, proportional-integral control. The duty cycle D* is the ratio of the on period Ton to one switching period Tsw of the lower arm switch SWL (Ton / Tsw).

[0031] The switch control unit 80 generates a gate signal for the lower arm switch SWL based on the calculated duty cycle D*. The switch control unit 80 controls the switching of the lower arm switch SWL by outputting a gate signal to the lower arm switch SWL. In boost control, the switch control unit 80 may keep the upper arm switch SWH off, or it may alternately turn on the upper, lower arm switches SWH and SWL.

[0032] Incidentally, the individual output voltage value VHr includes a voltage error, which is the deviation from the actual output voltage value of the DC-DC converter. The voltage error may include gain error and offset error included in the detected value of the second voltage sensor 42, disturbance noise, and errors caused by the timing difference of the detection of the second voltage sensor 42 in each power converter 30. Furthermore, the reactor current value ILr includes a current error, which is the deviation from the actual current value flowing through the reactor 31. The current error may include gain error and offset error included in the detected value of the current sensor 40, disturbance noise, and errors caused by the timing difference of the detection of the current sensor 40 in each power converter 30.

[0033] The adverse effects of voltage errors on boost control will be explained using the case where voltage errors are included as an example. Of the two power converters 30, the one in which a first voltage error that is higher than the actual output voltage value is included in the individual output voltage value VHr is designated as the first power converter, and the one in which a second voltage error that is lower than the actual output voltage value is included in the individual output voltage value VHr is designated as the second power converter. The ECU 50 of the first power converter performs boost control by feedback controlling the individual output voltage value VHr, which includes the first voltage error, to the output voltage command value VH*, and the ECU 50 of the second power converter performs boost control by feedback controlling the individual output voltage value VHr, which includes the second voltage error, to the output voltage command value VH*.

[0034] In this case, the reactor current command value IL* becomes relatively small in the first power converter, and relatively large in the second power converter. As a result, a power imbalance occurs in which the actual output voltage value of the first power converter becomes lower than the actual output voltage value of the second power converter, and the output power value of the second power converter becomes greater than the output power value of the first power converter. In this case, the second power converter may overheat, and its reliability may decrease.

[0035] Therefore, as shown in Figure 3, each ECU 50 in this embodiment is equipped with a voltage correction value calculation unit 60, a current correction value calculation unit 70, a voltage addition unit 53, and a current addition unit 54. The voltage correction value calculation unit 60 and the voltage addition unit 53 correspond to the "voltage correction unit," and the current correction value calculation unit 70 and the current addition unit 54 correspond to the "current correction unit."

[0036] As shown in Figure 4, the voltage correction value calculation unit 60 includes a reference current calculation unit 61, a current deviation calculation unit 62, and a first feedback control unit 63. The reference current calculation unit 61 calculates the reference current value ILext* (=Pext* / VLext) by dividing the output power command value Pext* by the common input voltage value VLext.

[0037] The current deviation calculation unit 62 calculates the current deviation value ΔIL (=ILext*-ILc) by subtracting the corrected current value ILc output from the current addition unit 54 from the reference current value ILext*.

[0038] The first feedback control unit 63 calculates a voltage correction value VC as a manipulated variable for feedback control to set the current deviation value ΔIL to 0. The feedback control used in the first feedback control unit 63 is, for example, proportional-integral control.

[0039] Returning to the explanation of Figure 3, the voltage correction value VC output from the voltage correction value calculation unit 60 is input to the voltage addition unit 53. The voltage addition unit 53 calculates the corrected output voltage value VHc (=VHr+VC) by adding the voltage correction value VC to the individual output voltage value VHr.

[0040] As shown in Figure 5, the current correction value calculation unit 70 includes a first calculation unit 71, a second calculation unit 72, a voltage deviation calculation unit 73, an excess / deficit current calculation unit 74, and a second feedback control unit 75. The first calculation unit 71 calculates the square of the common output voltage value VHext, and the second calculation unit 72 calculates the square of the corrected output voltage value VHc.

[0041] The voltage deviation calculation unit 73 calculates the voltage deviation value ΔVch by subtracting the square of the corrected output voltage value VHc from the square of the common output voltage value VHext.

[0042] The excess / undercurrent calculation unit 74 calculates the excess / undercurrent deviation value ΔIch shown in equation (eq1) below, based on the common input voltage value VLext and the voltage deviation value ΔVch. In equation (eq1), Ch represents the capacitance of the second capacitor 33, and fc represents the switching frequency (=1 / Tsw) of the upper and lower arm switches SWH and SWL.

[0043]

number

[0044] The second feedback control unit 75 calculates a current correction value IC as an manipulated variable for feedback control to set the excess / undercurrent deviation value ΔIch to zero. The feedback control used in the second feedback control unit 75 is, for example, proportional-integral control.

[0045] Returning to the explanation of Figure 3, the current correction value IC output from the current correction value calculation unit 70 is input to the current addition unit 54. The current addition unit 54 calculates the corrected current value ILc (=ILr+IC) by adding the current correction value IC to the reactor current value ILr.

[0046] The reason why power imbalance can be suppressed by calculating the corrected output voltage value VHc and corrected current value ILc as described above will now be explained.

[0047] As shown in Figure 6, when the actual output voltage values ​​of each power converter 30 are equal, if the individual output voltage values ​​VHr used in the boost control of each power converter 30 differ due to voltage errors, a power imbalance (i.e., an imbalance in the current flowing through the reactor 31) occurs in each power converter 30. ΔVs shown in Figure 6 represents the difference between the common output voltage value VHext and the individual output voltage value VHr.

[0048] On the other hand, the effect of the different individual output voltage values ​​VHr in each power converter 30 is expressed as the difference ΔIs (=ILext*-ILc) between the corrected current value ILc and the reference current value ILext*, as shown in Figure 7. Here, as shown in Figure 8, it was confirmed that the relationship between the difference ΔVs between the common output voltage value VHext and the individual output voltage value VHr, and the difference ΔIs between the corrected current value ILc and the reference current value ILext*, is positively correlated (specifically, monotonically increasing). Therefore, basically, power imbalance can be suppressed by correcting the individual output voltage value VHr based on the relationship between ΔIs and the voltage correction value VC shown in Figure 9. In more detail, the voltage correction value calculation unit 60 calculates a voltage correction value VC such that the deviation between the reference current value ILext* and the reactor current value ILr approaches 0, and power imbalance can be suppressed by correcting the individual output voltage value VHr with the latest calculated voltage correction value VC.

[0049] In reality, current errors occur in addition to voltage errors, and as shown in Figure 10, the reactor current value ILr, which is the detected value of the current sensor 40, differs due to the influence of current errors. ΔIs shown in Figure 10 indicates the amount of deviation between the reference current value ILext and the reactor current value ILr. Therefore, there is a concern that the correction process described above, based solely on the voltage correction value VC, may not be able to accurately suppress power imbalance.

[0050] On the other hand, the effect of different reactor current values ​​ILr in each power converter 30 is expressed as the difference ΔVs (=VHext-VHc) between the corrected output voltage value VHc and the common output voltage value VHext, as shown in Figure 11. Here, as shown in Figure 12, it was confirmed that the relationship between the difference ΔIs between the reference current value ILext* and the reactor current value ILr, and the difference ΔVs between the corrected output voltage value VHc and the common output voltage value VHext, is negatively correlated (specifically, a monotonically decreasing relationship). Therefore, basically, power imbalance can be suppressed by correcting the reactor current value ILr based on the relationship between ΔVs and the current correction value IC shown in Figure 13. In more detail, the current correction value calculation unit 70 calculates a current correction value IC such that the excess / deficit current deviation value ΔIch approaches 0, and the reactor current value ILr is corrected by the latest calculated current correction value IC, thereby accurately suppressing power imbalance.

[0051] Figure 14 is a flowchart of the boost control performed by each ECU 50. The boost control process is repeatedly performed by the ECU 50, for example, at a predetermined control cycle.

[0052] In step S10, the common input voltage value VLext, the common output voltage value VHext, the output power command value Pext*, and the output voltage command value VH* are obtained.

[0053] In step S11, the reactor current value ILr, individual input voltage value VLr, and individual output voltage value VHr are obtained.

[0054] In step S12, the voltage correction value calculation unit 60 performs the calculation of the voltage correction value VC. Specifically, in step S20 of Figure 15, the reference current calculation unit 61 calculates the reference current value ILext* based on the acquired output power command value Pext* and common input voltage value VLext. In step S21, the current deviation calculation unit 62 calculates the current deviation value ΔIL by calculating the latest corrected current value ILc from the reference current value ILext*. Then, the first feedback control unit 63 calculates the current correction value IC based on the current deviation value ΔIL.

[0055] Returning to the explanation of Figure 14, in step S13, the voltage summing unit 53 calculates the corrected output voltage value VHc by adding the latest calculated voltage correction value VC to the acquired individual output voltage value VHr. In step S14, the voltage control unit 51 calculates the reactor current command value IL* based on the corrected output voltage value VHc and the output voltage command value VH*.

[0056] In step S15, the current correction value calculation unit 70 performs the calculation of the current correction value IC. Specifically, in step S30 of Figure 16, the first calculation unit 71, the second calculation unit 72, the voltage deviation calculation unit 73, and the excess / undercurrent calculation unit 74 calculate the excess / undercurrent deviation value ΔIch based on the common output voltage value VHext, the latest corrected output voltage value VHc calculated in step S13, and the common input voltage value VLext. In step S31, the second feedback control unit 75 calculates the current correction value IC based on the excess / undercurrent deviation value ΔIch.

[0057] Returning to the explanation of Figure 14, in step S16, the current summing unit 54 calculates the corrected current value ILc by adding the latest calculated current correction value IC to the acquired reactor current value ILr.

[0058] In step S17, the current control unit 52 calculates the duty cycle D* based on the corrected current value ILc and the reactor current command value IL*. In step S18, the switch control unit 80 performs switching control of the lower arm switch SWL based on the duty cycle D*.

[0059] As described above, according to this embodiment, as shown in Figure 17, it is possible to suppress variations in the output voltage value used in boost control, and as shown in Figure 18, it is possible to suppress variations in the reactor current value used in boost control. This makes it possible to accurately suppress power imbalance.

[0060] <Modified form of the first embodiment> The voltage correction value calculation unit 60 shown in Figure 4 may include a voltage correction value limiting unit that limits the voltage correction value VC calculated by the first feedback control unit 63 to its upper and lower limits. Furthermore, when proportional-integral control is used as feedback control, the first feedback control unit 63 may limit the integral term calculated based on the current deviation value ΔIL to its upper and lower limits.

[0061] The current correction value calculation unit 70 shown in Figure 5 may include a current correction value limiting unit that limits the current correction value IC calculated by the second feedback control unit 75 to its upper and lower limits. Furthermore, when proportional-integral control is used as feedback control, the second feedback control unit 75 may limit the integral term calculated based on the excess / deficit current deviation value ΔIch to its upper and lower limits.

[0062] The current correction value calculation unit 70 may calculate the voltage deviation value ΔVch (=VHext-VHc) by subtracting the corrected output voltage value VHc from the common output voltage value VHext. In this case, for example, the coefficient multiplied by the voltage deviation value ΔVch in the excess / undercurrent calculation unit 74 should be changed.

[0063] <Second Embodiment> The second embodiment will now be described, focusing on the differences from the first embodiment, with reference to the drawings. In this embodiment, the voltage correction value calculation unit 60 of each ECU 50 receives the common output voltage value VHext and the individual output voltage value VHr as input. As shown in Figure 19, when the voltage correction value calculation unit 60 of each ECU 50 determines that the switching control has stopped and the boost control has stopped, it operates the voltage switching unit 64 so that "VHext-VHr" is output to the voltage addition unit 53 as the voltage correction value VC. In this case, the voltage addition unit 53 calculates "VHr+(VHext-VHr)" and outputs the common output voltage value VHext as the corrected output voltage value VHc to the voltage control unit 51.

[0064] On the other hand, if the voltage correction value calculation unit 60 of each ECU 50 determines that boost control is being performed, it operates the voltage switching unit 64 so that the voltage correction value VC calculated by the first feedback control unit 63 is output to the voltage addition unit 53.

[0065] As a result of the above processing by the voltage correction value calculation unit 60, the output voltage value used by the voltage control unit 51 during the transient state immediately after the start of boost control becomes the common output voltage value VHext. This ensures that the output voltage values ​​used by each ECU 50 are the same (common output voltage value VHext), thereby suppressing power imbalance during the transient state immediately after the start of boost control.

[0066] In this embodiment, the current correction value calculation unit 70 of each ECU 50 receives the reference current value ILext* and the reactor current value ILr as input. As shown in Figure 20, when the current correction value calculation unit 70 of each ECU 50 determines that the boost control is stopped, it operates the current switching unit 76 so that "ILext*-ILr" is output to the current addition unit 54 as the current correction value IC. In this case, the reference current value ILext* is the latest value. The current addition unit 54 outputs the reference current value ILext* as the corrected current value ILc to the current control unit 52 by performing the calculation "ILr+(ILext*-ILr)".

[0067] On the other hand, if the current correction value calculation unit 70 of each ECU 50 determines that boost control is being performed, it operates the current switching unit 76 so that the current correction value IC calculated by the second feedback control unit 75 is output to the current addition unit 54.

[0068] As a result of the processing performed by the current correction value calculation unit 70, the current value used by the current control unit 52 during the transient state immediately after the start of boost control becomes the reference current value ILext*. This ensures that the current value used by each ECU 50 is the same (reference current value ILext*), thereby suppressing power imbalance during the transient state immediately after the start of boost control.

[0069] <Third Embodiment> The third embodiment will now be described, focusing on the differences from the second embodiment, with reference to the drawings. In this embodiment, as shown in Figure 21, the voltage correction value calculation unit 60 of each ECU 50 operates the voltage switching unit 65 so that "0" is output to the voltage addition unit 53 as the voltage correction value VC when it determines that the correction processing of the individual output voltage value VHr is restricted. In this case, the voltage addition unit 53 does not perform correction of the individual output voltage value VHr. Therefore, the voltage control unit 51 calculates the reactor current command value IL* as an operation variable for feedback control of the input individual output voltage value VHr to the output voltage command value VH*.

[0070] On the other hand, if the voltage correction value calculation unit 60 of each ECU 50 determines that correction processing is permitted, it operates the voltage switching unit 65 so that the voltage correction value VC calculated by the first feedback control unit 63 is output to the voltage addition unit 53.

[0071] This allows the correction process to be stopped when correction of the individual output voltage value VHr is not necessary, thereby reducing the computational load on the ECU50.

[0072] Here, an example of a method for determining whether to restrict or permit the correction process will be explained using Figure 22. The voltage correction value calculation unit 60 determines that if the magnitude of the current deviation value ΔIL calculated by the current deviation calculation unit 62 exceeds the current threshold Ith, it will permit the correction process for the individual output voltage value VHr. On the other hand, the voltage correction value calculation unit 60 determines that if the magnitude of the current deviation value ΔIL is less than or equal to the current threshold Ith, it will restrict the correction for the individual output voltage value VHr.

[0073] This determination method suppresses fluctuations in the output voltage value of the DC-DC converter caused by the correction process, and stabilizes the output voltage value of the DC-DC converter.

[0074] As shown in Figure 23, the current correction value calculation unit 70 of each ECU 50 operates the current switching unit 77 so that "0" is output to the current addition unit 54 as the current correction value IC when it determines that the correction processing of the reactor current value ILr is restricted. In this case, the reactor current value ILr is output from the current addition unit 54 to the current control unit 52. Therefore, the current control unit 52 calculates the duty cycle D* as an operation variable for feedback control of the input reactor current value ILr to the reactor current command value IL*.

[0075] On the other hand, if the current correction value calculation unit 70 of each ECU 50 determines that correction processing is permitted, it operates the current switching unit 77 so that the current correction value IC calculated by the second feedback control unit 75 is output to the current addition unit 54.

[0076] This allows the correction process to be stopped, for example, when correction of the reactor current value ILr is not necessary, thereby reducing the computational load on the ECU 50.

[0077] Here, an example of a method for determining whether to restrict or permit the correction process will be explained using Figure 24. The current correction value calculation unit 70 determines that if the magnitude of the excess / deficit current deviation value ΔIch calculated by the excess / deficit current calculation unit 74 exceeds the threshold Iα, it will permit the correction process for the reactor current value ILr. On the other hand, the current correction value calculation unit 70 determines that if the magnitude of the excess / deficit current deviation value ΔIch is less than or equal to the threshold Iα, it will restrict the correction process.

[0078] This determination method suppresses fluctuations in the output voltage value of the DC-DC converter caused by the correction process, and stabilizes the output voltage value of the DC-DC converter.

[0079] <Modified form of the third embodiment> The method for determining whether to limit or allow the correction process for the reactor current value ILr is not limited to the method shown in Figure 24, but may also be the method described below.

[0080] After the start of the boost control of each power conversion device 30, the output voltage command value VH* transmitted from the VCU 45 to each ECU 50 gradually increases from 0 toward the specified voltage Vp as shown in FIG. 25. In the example shown in FIG. 25, the output voltage command value VH* rises at a constant speed. After the input output voltage command value VH* starts to gradually increase, when the current correction value calculation unit 70 of each ECU 50 determines that a predetermined time Tth has elapsed since the timing t1 when the output voltage command value VH* reached the determination voltage Vα (<Vp), the correction process is permitted. On the other hand, when the current correction value calculation unit 70 determines that the predetermined time Tth has not elapsed since the timing t1, the correction process is restricted. In FIG. 25, t2 indicates the timing when the predetermined time Tth has elapsed since the timing t1. The predetermined time Tth may be set to a value that can determine, for example, that the individual output voltage value VHr of each DCDC converter converges to the specified voltage Vp.

[0081] In the transient state of the output voltage command value VH* immediately after the start of the boost control, the actual output voltage value of each DCDC converter can vary significantly. In this case, for example, due to the deviation in the detection timing of the individual output voltage value VHr in each ECU 50, the variation in the voltage error in each ECU 50 increases, and the reactor current value ILr can be excessively corrected. As a result, the power imbalance tends to increase. On the other hand, according to the determination method shown in FIG. 25, since the correction process can be started after getting out of the situation where the power imbalance tends to increase, the occurrence of the power imbalance can be suitably suppressed.

[0082] · The voltage correction value calculation unit 60 and the current correction value calculation unit 70 may permit the correction process, for example, when the torque of the rotating electrical machine included in the electrical load 20 is in a steady state, and restrict the correction process in the transient state where the torque of the rotating electrical machine changes suddenly.

[0083] <Fourth Embodiment> The fourth embodiment will now be described, focusing on the differences from the first embodiment, with reference to the drawings. In this embodiment, as shown in Figure 26, the installation position of the current sensor 40 in each power converter 30 has been changed. Specifically, the current sensor 40 is provided in the power converter 30 so as to be able to detect the current value flowing to the second high-potential side terminal TH2.

[0084] The voltage control unit 51 calculates the current command value IL* flowing to the second high-potential terminal TH2 as an manipulated variable for feedback control of the corrected output voltage value VHc to the output voltage command value VH*. The current control unit 52 calculates the duty cycle D* as an manipulated variable for feedback control of the corrected current value ILc to the current command value IL*.

[0085] In this embodiment, the voltage correction value calculation unit 60 receives a common output voltage value VHext as input, as shown in Figure 27. The reference current calculation unit 61 of the voltage correction value calculation unit 60 calculates the reference current value ILext* by dividing the output power command value Pext* by the common output voltage value VHext, instead of the common input voltage value VLext, as shown in Figure 28.

[0086] According to the embodiment described above, the same effects as those of the first embodiment can be achieved.

[0087] <Fifth Embodiment> The fifth embodiment will be described below, focusing on the differences from the first embodiment, with reference to the drawings. The DC-DC converter in the power conversion device is not limited to a non-isolated DC-DC converter, but may also be an isolated DC-DC converter equipped with a transformer. As an example of an isolated DC-DC converter, Figure 29 shows a DAB (Dual Active Bridge) type.

[0088] Each power converter 130 includes a DC-DC converter comprising a first full-bridge circuit FB1, a second full-bridge circuit FB2, a transformer 131 for power transfer between the full-bridge circuits FB1 and FB2, a first capacitor 132, and a second capacitor 133. The transformer 131 includes a first coil 131A connected to the first full-bridge circuit FB1, a second coil 131B connected to the second full-bridge circuit FB2, and a core that magnetically couples with each coil 131A and 131B.

[0089] The first full-bridge circuit FB1 includes switches QA1, QA2, QA3, and QA4 for the first, second, third, and fourth A sections. The second full-bridge circuit FB2 includes switches QB1, QB2, QB3, and QB4 for the first, second, third, and fourth B sections. In this embodiment, each of the switches QA1 to QA4 and QB1 to QB4 is an IGBT.

[0090] The power converter 130 includes a current sensor 140, a first voltage sensor 141 (corresponding to an "individual input voltage sensor"), a second voltage sensor 142 (corresponding to an "individual output voltage sensor"), and an ECU (not shown) as a control device. The current sensor 140 detects the current flowing through the first coil 131A (corresponding to a "control current value") as a reactor current value ILr. The first voltage sensor 141 detects the terminal voltage of the first capacitor 132 as an individual input voltage value VLr, and the second voltage sensor 142 detects the terminal voltage of the second capacitor 133 as an individual output voltage value VHr. The detected values ​​of each sensor 140 to 142 are input to the ECU.

[0091] Furthermore, the switching control method for each full-bridge circuit FB1, FB2 in each power converter 130 for power transfer between the DC power supply 10 and the electrical load 20 is publicly known, as described, for example, in Japanese Patent Application Publication No. 2021-145407. Therefore, a description of this switching control method will be omitted.

[0092] When power is transmitted from the DC power supply 10 to the electrical load 20 via each power converter 130, the first high-potential terminal TH1 corresponds to the "high-potential input terminal," the first low-potential terminal TL1 corresponds to the "low-potential input terminal," the second high-potential terminal TH2 corresponds to the "high-potential output terminal," and the second low-potential terminal TL2 corresponds to the "low-potential output terminal."

[0093] On the other hand, if, for example, a storage battery is provided instead of the electrical load 20, and power is transmitted from this storage battery to the DC power supply 10 via each power converter 130, then the second high-potential terminal TH2 corresponds to the "high-potential input terminal," the second low-potential terminal TL2 corresponds to the "low-potential input terminal," the first high-potential terminal TH1 corresponds to the "high-potential output terminal," and the first low-potential terminal TL1 corresponds to the "low-potential output terminal."

[0094] In the embodiment described above, the same processing as shown in Figures 3-5 and 14-16 can be applied.

[0095] <Other Embodiments> Furthermore, each of the above embodiments may be implemented with the following modifications.

[0096] In the configuration shown in Figure 29, a current sensor may be provided to detect the current flowing through the second coil 131B instead of the first coil 131A.

[0097] The non-isolated DC-DC converter is not limited to a boost DC-DC converter; for example, it may also be a buck DC-DC converter capable of performing buck control, which reduces the input voltage to output a lower voltage. Step-down control is also acceptable.

[0098] The detection values ​​of each common voltage sensor 43, 44 may be input directly to the ECU of each power converter without going through the VCU 45.

[0099] The switch in the DC-DC converter is not limited to IGBTs; for example, it may be an N-channel MOSFET with a body diode. In this case, the high-potential terminal of the switch is the drain, and the low-potential terminal of the switch is the source.

[0100] The control unit and its method described herein may be implemented by a dedicated computer provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program. Alternatively, the control unit and its method described herein may be implemented by a dedicated computer provided by configuring a processor by one or more dedicated hardware logic circuits. Alternatively, the control unit and its method described herein may be implemented by one or more dedicated computers configured by a combination of a processor and memory programmed to perform one or more functions and a processor configured by one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by the computer on a computer-readable non-transitional tangible recording medium.

[0101] The following describes the characteristic configurations extracted from each of the embodiments described above. [Configuration 1] DC power supply (10), The DC power supply's output power is supplied to the target unit (20), Applicable to a system comprising, in a parallel power supply unit comprising multiple power converters (30, 130), Each of the aforementioned power converters, A DC-DC converter having switches (SWH, SWL, QA1~QB4), reactors (31, 131A, 131B), a high-potential input terminal (TH1), a low-potential input terminal (TL1), a high-potential output terminal (TH2), and a low-potential output terminal (TL2), which repeatedly stores magnetic energy in the reactor and releases magnetic energy from the reactor by switching control of the switches, thereby transforming the DC voltage input from the high-potential input terminal and the low-potential input terminal and outputting it from the high-potential output terminal and the low-potential output terminal, Individual output voltage sensors (42, 142) that detect individual output voltage values ​​(VHr), which are the voltage values ​​between the high-potential input terminal and the low-potential input terminal, A current sensor (40, 140) detects a control current value (ILr), which is either the current value flowing through the reactor or the current value flowing to the high-potential output terminal. The system includes a control device (50) to which the detected individual output voltage value and the control current value are input, The aforementioned system, A high-potential input path (11H) is an electrical path that connects the positive terminal of the DC power supply and the high-potential input terminal of each DC-DC converter, A low-potential input path (11L) is an electrical path that connects the negative terminal of the DC power supply and the low-potential input terminal of each DC-DC converter, The high-potential output path (12H) is an electrical path that connects the high-potential side terminal of the supply target unit and the high-potential side output terminal of each DC-DC converter, The low-potential output path (12L) is an electrical path that connects the low-potential terminal of the supply target unit and the low-potential output terminal of each DC-DC converter, A common output voltage sensor (44) detects a common output voltage value (VHext), which is the voltage value between the high-potential output path and the low-potential output path. Equipped with, The parallel power supply unit is configured such that the detected common output voltage value, the common output voltage command value (VH*) for each power converter, and the common output power command value (Pext*) for each power converter are input to each control device. Each of the control devices is a parallel power supply device that performs switching control of the switches based on the input output voltage command value, the individual output voltage value, the control current value, the output power command value, and the common output voltage value. [Configuration 2] The system includes a common input voltage sensor (43) that detects a common input voltage value (VLext), which is the voltage value between the high-potential side input path and the low-potential side input path. The parallel power supply unit is configured such that the detected common input voltage value is input to each of the control devices. The control current value is the current value flowing through the reactor (31), Each of the aforementioned control devices is A voltage correction unit (53, 60) calculates a corrected output voltage value (VHc), which is a value obtained by correcting the input individual output voltage values, A current correction unit (54, 70) calculates a corrected current value (ILc), which is a value obtained by correcting the input control current value. A voltage control unit (51) calculates a current command value (IL*) flowing through the reactor as an manipulated variable for feedback control of the calculated corrected output voltage value to the input output voltage command value, A current control unit (52) calculates an manipulated variable (D*) for feedback control of the calculated corrected current value to the calculated current command value, A switch control unit (80) performs switching control of the switch based on the manipulated amount calculated by the current control unit, Equipped with, In each of the control devices, the voltage correction unit calculates the corrected output voltage value based on the input output power command value, the common input voltage value, and the individual output voltage value, as well as the calculated corrected current value. In each of the control devices, the current correction unit calculates the corrected current value based on the input common input voltage value, the common output voltage value, and the control current value, as well as the calculated corrected output voltage value, in the parallel power supply device according to Configuration 1. [Configuration 3] In each of the above control devices, the voltage correction unit is: The reference current value (ILext) is calculated by dividing the output power command value by the common input voltage value. A voltage correction value (VC) is calculated as an manipulated variable for feedback control of the calculated corrected current value to the reference current value. The parallel power supply device according to configuration 2, which calculates a corrected output voltage value by correcting the input individual output voltage values ​​based on the voltage correction value. [Structure 4] The system includes a common input voltage sensor (43) that detects a common input voltage value (VLext), which is the voltage value between the high-potential side input path and the low-potential side input path. The parallel power supply unit is configured such that the detected common input voltage value is input to each of the control devices. The control current value is the current value that flows to the high-potential output terminal. Each of the aforementioned control devices is A voltage correction unit (53, 60) calculates a corrected output voltage value (VHc), which is a value obtained by correcting the input individual output voltage values, A current correction unit (54, 70) calculates a corrected current value (ILc), which is a value obtained by correcting the input control current value. A voltage control unit (51) calculates a current command value (IL*) that flows to the high-potential side output terminal as an manipulated variable for feedback control of the calculated corrected output voltage value to the input output voltage command value, A current control unit (52) calculates an manipulated variable (D*) for feedback control of the calculated corrected current value to the calculated current command value, A switch control unit (80) performs switching control of the switch based on the manipulated amount calculated by the current control unit, Equipped with, In each of the control devices, the voltage correction unit calculates the corrected output voltage value based on the input output power command value, the common output voltage value, and the individual output voltage value, as well as the calculated corrected current value. In each of the control devices, the current correction unit calculates the corrected current value based on the input common output voltage value, the common input voltage value, and the control current value, as well as the calculated corrected output voltage value, in the parallel power supply device according to Configuration 1. [Composition 5] In each of the above control devices, the voltage correction unit is: The reference current value (ILext*) is calculated by dividing the output power command value by the common output voltage value. A voltage correction value (VC) is calculated as an manipulated variable for feedback control of the calculated corrected current value to the reference current value. The parallel power supply according to configuration 4, which calculates a value obtained by correcting the input individual output voltage values ​​based on the voltage correction value as the corrected output voltage value. [Composition 6] In each of the above control devices, the voltage correction unit is: If it is determined that the DC-DC converter is undergoing voltage transformation control, the individual output voltage values ​​that have been input are corrected based on the voltage correction value, and this corrected output voltage value is calculated. The parallel power supply according to configuration 3 or 5, wherein if it is determined that the voltage transformation control is stopped, the input common output voltage value is set to the corrected output voltage value. [Composition 7] In each of the above control devices, the voltage correction unit is: If it is determined that the magnitude of the difference between the calculated corrected current value and the reference current value exceeds the current threshold (Ith), the individual output voltage value that was input is corrected based on the voltage correction value, and this corrected output voltage value is calculated. A parallel power supply according to configuration 3 or 5, which, when it is determined that the magnitude of the difference between the corrected current value and the reference current value is less than or equal to the current threshold, limits the correction to the input individual output voltage value. [Structure 8] In each of the above control devices, the current correction unit is: A current correction value (IC) is calculated as an manipulated variable for feedback control to set the correlation value (ΔIch) of the difference between the common output voltage value and the individual output voltage values ​​to 0. A parallel power supply device according to any one of configurations 2 to 7, which calculates a corrected current value by correcting the input control current value based on the current correction value. [Composition 9] In each of the above control devices, the voltage correction unit is: The reference current value (ILext) is calculated by dividing the output power command value by the common input voltage value. A voltage correction value (VC) is calculated as an manipulated variable for feedback control of the calculated corrected current value to the reference current value. In each of the above control devices, the current correction unit is: If it is determined that the DC-DC converter is undergoing voltage transformation control, the input control current value is corrected based on the current correction value, and this corrected current value is calculated. The parallel power supply device according to configuration 8, wherein if it is determined that the voltage transformation control has been stopped, the calculated reference current value is set to the corrected current value. [Configuration 10] In each of the above control devices, the current correction unit is: If it is determined that the magnitude of the calculated correlation value exceeds the threshold (Iα), the input control current value is corrected based on the current correction value, and this corrected current value is calculated. The parallel power supply according to configuration 8 or 9, which, when it is determined that the magnitude of the correlation value is less than or equal to the threshold, limits the correction to the input control current value. [Composition 11] The parallel power supply is configured such that, after the start of voltage transformation control of the DC-DC converter, the output voltage command value gradually increases toward a specified voltage (Vp). In each of the above control devices, the current correction unit is: After the input output voltage command value begins to gradually increase, if it is determined that a predetermined time (Tth) has elapsed since the timing at which the output voltage command value reaches a determination voltage (Vα) lower than the specified voltage, the input control current value is corrected based on the current correction value, and this corrected current value is calculated. A parallel power supply according to configuration 8 or 9, which, if it is determined that the predetermined time has not elapsed from the timing after the input output voltage command value has started to gradually increase, limits the correction to the input control current value. [Composition 12] DC power supply (10), The DC power supply's output power is supplied to the target unit (20), Multiple power converters (30, 130), In a program applied to a system that includes the following features, Each of the aforementioned power converters, A DC-DC converter having switches (SWH, SWL, QA1~QB4), reactors (31, 131A, 131B), a high-potential input terminal (TH1), a low-potential input terminal (TL1), a high-potential output terminal (TH2), and a low-potential output terminal (TL2), which repeatedly stores magnetic energy in the reactor and releases magnetic energy from the reactor by switching control of the switches, thereby transforming the DC voltage input from the high-potential input terminal and the low-potential input terminal and outputting it from the high-potential output terminal and the low-potential output terminal, Individual output voltage sensors (33, 133) that detect individual output voltage values ​​(VHr), which are the voltage values ​​between the high-potential input terminal and the low-potential input terminal, A current sensor (40, 140) detects a control current value (ILr), which is either the current value flowing through the reactor or the current value flowing to the high-potential output terminal. The system includes a control device (50) to which the detected individual output voltage value and the control current value are input, The aforementioned system, A high-potential input path (11H) is an electrical path that connects the positive terminal of the DC power supply and the high-potential input terminal of each DC-DC converter, A low-potential input path (11L) is an electrical path that connects the negative terminal of the DC power supply and the low-potential input terminal of each DC-DC converter, The high-potential output path (12H) is an electrical path that connects the high-potential side terminal of the supply target unit and the high-potential side output terminal of each DC-DC converter, The low-potential output path (12L) is an electrical path that connects the low-potential terminal of the supply target unit and the low-potential output terminal of each DC-DC converter, A common output voltage sensor (44) detects a common output voltage value (VHext), which is the voltage value between the high-potential output path and the low-potential output path. Equipped with, The system is configured such that the detected common output voltage value, the common output voltage command value (VH*) for each power converter, and the common output power command value (Pext*) for each power converter are input to each control device. A program that causes each of the control devices to perform switching control of the switches based on the input output voltage command value, the individual output voltage value, the control current value, the output power command value, and the common output voltage value.

[0102] This disclosure is described in accordance with the embodiments, but it is understood that this disclosure is not limited to such embodiments or structures. This disclosure also includes various modifications and variations within the equivalence. In addition, various combinations and forms, as well as other combinations and forms that include only one, more, or fewer of those elements, fall within the scope and concept of this disclosure.

Claims

1. DC power supply (10) and The DC power supply's output power is supplied to the target unit (20), Applicable to a system comprising, in a parallel power supply unit comprising multiple power converters (30, 130), Each of the aforementioned power converters, A DC-DC converter having switches (SWH, SWL, QA1 to QB4), reactors (31, 131A, 131B), a high-potential input terminal (TH1), a low-potential input terminal (TL1), a high-potential output terminal (TH2), and a low-potential output terminal (TL2), which repeatedly stores magnetic energy in the reactor and releases magnetic energy from the reactor by switching control of the switches, thereby transforming the DC voltage input from the high-potential input terminal and the low-potential input terminal and outputting it from the high-potential output terminal and the low-potential output terminal, Individual output voltage sensors (42, 142) that detect individual output voltage values ​​(VHr), which are the voltage values ​​between the high-potential output terminal and the low-potential output terminal, A current sensor (40, 140) detects a control current value (ILr), which is either the current value flowing through the reactor or the current value flowing to the high-potential output terminal. The system includes a control device (50) to which the detected individual output voltage value and the control current value are input, The aforementioned system, A high-potential input path (11H) is an electrical path that connects the positive terminal of the DC power supply and the high-potential input terminal of each DC-DC converter, A low-potential input path (11L) is an electrical path that connects the negative terminal of the DC power supply and the low-potential input terminal of each DC-DC converter, The high-potential output path (12H) is an electrical path that connects the high-potential side terminal of the supply target unit and the high-potential side output terminal of each DC-DC converter, The low-potential output path (12L) is an electrical path that connects the low-potential terminal of the supply target unit and the low-potential output terminal of each DC-DC converter, A common output voltage sensor (44) detects a common output voltage value (VHext), which is the voltage value between the high-potential side output path and the low-potential side output path. Equipped with, The parallel power supply unit is configured such that the detected common output voltage value, the common output voltage command value (VH*) for each power converter, and the common output power command value (Pext*) for each power converter are input to each control device. Each of the control devices is a parallel power supply device that performs switching control of the switches based on the input output voltage command value, the individual output voltage value, the control current value, the output power command value, and the common output voltage value.

2. The system includes a common input voltage sensor (43) that detects a common input voltage value (VLext), which is the voltage value between the high-potential side input path and the low-potential side input path. The parallel power supply unit is configured such that the detected common input voltage value is input to each of the control devices. The control current value is the current value flowing through the reactor (31), Each of the aforementioned control devices is A voltage correction unit (53, 60) calculates a corrected output voltage value (VHc), which is a value obtained by correcting the input individual output voltage values, A current correction unit (54, 70) calculates a corrected current value (ILc), which is a value obtained by correcting the input control current value. A voltage control unit (51) calculates a current command value (IL*) flowing through the reactor as an manipulated variable for feedback control of the calculated corrected output voltage value to the input output voltage command value, A current control unit (52) calculates an manipulated variable (D*) for feedback control of the calculated corrected current value to the calculated current command value, A switch control unit (80) performs switching control of the switch based on the operation amount calculated by the current control unit, Equipped with, In each of the control devices, the voltage correction unit calculates the corrected output voltage value based on the input output power command value, the common input voltage value, and the individual output voltage value, as well as the calculated corrected current value. The parallel power supply device according to claim 1, wherein in each of the control devices, the current correction unit calculates the corrected current value based on the input common input voltage value, the common output voltage value, and the control current value, as well as the calculated corrected output voltage value.

3. In each of the above control devices, the voltage correction unit is: The reference current value (ILext) is calculated by dividing the output power command value by the common input voltage value. A voltage correction value (VC) is calculated as an manipulated variable for feedback control of the calculated corrected current value to the reference current value. The parallel power supply device according to claim 2, wherein the individual output voltage values ​​that are input are corrected based on the voltage correction value, and the corrected output voltage value is calculated as the corrected output voltage value.

4. The system includes a common input voltage sensor (43) that detects a common input voltage value (VLext), which is the voltage value between the high-potential side input path and the low-potential side input path. The parallel power supply unit is configured such that the detected common input voltage value is input to each of the control devices. The control current value is the current value that flows to the high-potential output terminal. Each of the aforementioned control devices is A voltage correction unit (53, 60) calculates a corrected output voltage value (VHc), which is a value obtained by correcting the input individual output voltage values, A current correction unit (54, 70) calculates a corrected current value (ILc), which is a value obtained by correcting the input control current value. A voltage control unit (51) calculates a current command value (IL*) that flows to the high-potential side output terminal as an input variable for feedback control of the calculated corrected output voltage value to the input output voltage command value, A current control unit (52) calculates an manipulated variable (D*) for feedback control of the calculated corrected current value to the calculated current command value, A switch control unit (80) performs switching control of the switch based on the operation amount calculated by the current control unit, Equipped with, In each of the control devices, the voltage correction unit calculates the corrected output voltage value based on the input output power command value, the common output voltage value, and the individual output voltage value, as well as the calculated corrected current value. The parallel power supply device according to claim 1, wherein in each of the control devices, the current correction unit calculates the corrected current value based on the input common output voltage value, the common input voltage value, and the control current value, as well as the calculated corrected output voltage value.

5. In each of the above control devices, the voltage correction unit is: The reference current value (ILext*) is calculated by dividing the output power command value by the common output voltage value. A voltage correction value (VC) is calculated as an manipulated variable for feedback control of the calculated corrected current value to the reference current value. The parallel power supply device according to claim 4, wherein the individual output voltage values ​​that are input are corrected based on the voltage correction value, and the corrected output voltage value is calculated as the corrected output voltage value.

6. In each of the above control devices, the voltage correction unit is: If it is determined that the DC-DC converter is performing voltage transformation control, the individual output voltage values ​​that have been input are corrected based on the voltage correction value, and this corrected output voltage value is calculated. The parallel power supply device according to claim 3 or 5, wherein if it is determined that the voltage transformation control is stopped, the input common output voltage value is set to the corrected output voltage value.

7. In each of the above control devices, the voltage correction unit is: If it is determined that the magnitude of the difference between the calculated corrected current value and the reference current value exceeds the current threshold (Ith), the individual output voltage value that was input is corrected based on the voltage correction value, and this corrected output voltage value is calculated. The parallel power supply device according to claim 3 or 5, which, when it is determined that the magnitude of the difference between the corrected current value and the reference current value is less than or equal to the current threshold, limits the correction to the input individual output voltage value.

8. In each of the above control devices, the current correction unit is: A current correction value (IC) is calculated as an manipulated variable for feedback control to set the correlation value (ΔIch) of the difference between the common output voltage value and the individual output voltage values ​​to zero. A parallel power supply device according to any one of claims 2 to 5, wherein the input control current value is corrected based on the current correction value to calculate the corrected current value.

9. In each of the above control devices, the voltage correction unit is: The reference current value (ILext) is calculated by dividing the output power command value by the common input voltage value. A voltage correction value (VC) is calculated as an manipulated variable for feedback control of the calculated corrected current value to the reference current value. In each of the above control devices, the current correction unit is: If it is determined that the DC-DC converter is performing voltage transformation control, the input control current value is corrected based on the current correction value, and this corrected current value is calculated. The parallel power supply device according to claim 8, wherein if it is determined that the voltage transformation control has been stopped, the calculated reference current value is set to the corrected current value.

10. In each of the above control devices, the current correction unit is: If it is determined that the magnitude of the calculated correlation value exceeds the threshold (Iα), the input control current value is corrected based on the current correction value, and this corrected current value is calculated. The parallel power supply device according to claim 8, wherein if it is determined that the magnitude of the correlation value is less than or equal to the threshold, the correction to the input control current value is limited.

11. The parallel power supply is configured such that, after the start of voltage transformation control of the DC-DC converter, the output voltage command value gradually increases toward a specified voltage (Vp). In each of the above control devices, the current correction unit is: After the input output voltage command value begins to gradually increase, if it is determined that a predetermined time (Tth) has elapsed since the timing at which the output voltage command value reaches a determination voltage (Vα) lower than the specified voltage, the input control current value is corrected based on the current correction value, and this corrected current value is calculated. The parallel power supply device according to claim 8, which, if it is determined that the predetermined time has not elapsed from the timing after the input output voltage command value has started to gradually increase, limits the correction to the input control current value.

12. DC power supply (10) and The DC power supply's output power is supplied to the target unit (20), Multiple power converters (30, 130) and In a program applied to a system that includes the following features, Each of the aforementioned power converters, A DC-DC converter having switches (SWH, SWL, QA1 to QB4), reactors (31, 131A, 131B), a high-potential input terminal (TH1), a low-potential input terminal (TL1), a high-potential output terminal (TH2), and a low-potential output terminal (TL2), which repeatedly stores magnetic energy in the reactor and releases magnetic energy from the reactor by switching control of the switches, thereby transforming the DC voltage input from the high-potential input terminal and the low-potential input terminal and outputting it from the high-potential output terminal and the low-potential output terminal, Individual output voltage sensors (33, 133) that detect individual output voltage values ​​(VHr), which are the voltage values ​​between the high-potential output terminal and the low-potential output terminal, A current sensor (40, 140) detects a control current value (ILr), which is either the current value flowing through the reactor or the current value flowing to the high-potential output terminal. The system includes a control device (50) to which the detected individual output voltage value and the control current value are input, The aforementioned system, A high-potential input path (11H) is an electrical path that connects the positive terminal of the DC power supply and the high-potential input terminal of each DC-DC converter, A low-potential input path (11L) is an electrical path that connects the negative terminal of the DC power supply and the low-potential input terminal of each DC-DC converter, The high-potential output path (12H) is an electrical path that connects the high-potential side terminal of the supply target unit and the high-potential side output terminal of each DC-DC converter, The low-potential output path (12L) is an electrical path that connects the low-potential terminal of the supply target unit and the low-potential output terminal of each DC-DC converter, A common output voltage sensor (44) detects a common output voltage value (VHext), which is the voltage value between the high-potential side output path and the low-potential side output path. Equipped with, The system is configured such that the detected common output voltage value, the common output voltage command value (VH*) for each power converter, and the common output power command value (Pext*) for each power converter are input to each control device. A program that causes each of the control devices to perform switching control of the switches based on the input output voltage command value, the individual output voltage value, the control current value, the output power command value, and the common output voltage value.

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