Power conversion device and program

Abstract

To provide a power conversion device and a program, capable of reducing a pulsation of a DC power while increasing the DC power to be output at the time of a power conversion using a single phase AC power supply.SOLUTION: A control device 70 provided in a power conversion device 10, performs a switching control of first and second upper arm switches S1H and S2H and first and second lower arm switches S1L and S2L in order to convert an AC power input from a first AC terminal Tac1 and a fourth AC terminal Tac4 into a DC power to output it from each of DC terminals TdcH and TdcL in a state of turning on a compensation switch 48, a first single phase charging switch 45, and a second single phase charging switch 46 in the case where it is determined that the single phase AC power supply is connected, and performs a switching control of third upper and lower arm switches S3H and S3L in order to reduce a pulsation of the DC power output from each of the DC terminals TdcH and TdcL by a charging and a discharging of a compensation capacitor 47.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a power conversion device and a program. [Background technology]

[0002] A power conversion device compatible with both a three-phase AC power supply and a single-phase AC power supply has been known, as described in Patent Document 1. This power conversion device includes a series connection of upper and lower arm switches for three phases, a series connection of upper and lower arm diodes, a high-potential side path, a low-potential side path, and a DC-side capacitor. The high-potential side path electrically connects the high-potential side terminals of each upper arm switch, the cathodes of the upper arm diodes, the high-potential side terminal of the capacitor, and the high-potential side DC terminal. The low-potential side path electrically connects the low-potential side terminals of each lower arm switch, the anodes of the lower arm diodes, the low-potential side terminal of the capacitor, and the low-potential side DC terminal.

[0003] The power conversion device further includes first to third inductors, wherein the first inductor electrically connects the connection point of the first upper and lower arm switches to a first AC terminal, the second inductor electrically connects the connection point of the second upper and lower arm switches to a second AC terminal, and the third inductor electrically connects the connection point of the third upper and lower arm switches to a third AC terminal.

[0004] The power conversion device includes a connection path that electrically connects the connection point of the upper and lower arm diodes to a fourth AC terminal, a first switch provided in the connection path, a second switch that electrically connects the first AC terminal to a second AC terminal, and a third switch that electrically connects the second AC terminal to a third AC terminal.

[0005] When a three-phase AC power supply is connected to the first AC terminal, the second AC terminal, and the third AC terminal, the power conversion device performs switching control of each upper and lower arm switch to convert AC power input from the first AC terminal, the second AC terminal, and the third AC terminal into DC power and output it from the high potential side DC terminal and the low potential side DC terminal when the first to third switches are turned off.

[0006] On the other hand, when a single-phase AC power supply is connected to the first AC terminal and the fourth AC terminal, the power conversion device controls the switching of each upper and lower arm switch with the first to third switches turned on to convert AC power input from the first AC terminal and the fourth AC terminal into DC power and output it from the high-potential side DC terminal and the low-potential side DC terminal. Because the second and third switches are turned on, all of the first to third inductors can be used as power transmission paths during power conversion using a single-phase AC power supply. This makes it possible to increase the DC power output from the high-potential side DC terminal and the low-potential side DC terminal. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Special Publication No. 2022-503713 Summary of the Invention [Problem to be solved by the invention]

[0008] During power conversion using a single-phase AC power supply, the pulsation of the DC power output from the high-potential DC terminal and the low-potential DC terminal becomes larger than during power conversion using a three-phase AC power supply. As a result, the capacitance of the capacitor that smooths the pulsation becomes larger, which in turn increases the size of the capacitor.

[0009] A main object of the present invention is to provide a power conversion device and a program that can reduce pulsation in DC power while increasing the DC power output during power conversion using a single-phase AC power supply. [Means for solving the problem]

[0010] The present invention provides a power supply comprising a first AC terminal, a second AC terminal, a third AC terminal, and a fourth AC terminal; a high potential side DC terminal and a low potential side DC terminal; Equipped with A power conversion device configured to allow a three-phase AC power supply to be connected to the first AC terminal, the second AC terminal, and the third AC terminal, and a single-phase AC power supply to be connected to the first AC terminal and the fourth AC terminal, a series connection of a first upper arm switch and a first lower arm switch; a series connection of a second upper arm switch and a second lower arm switch; a series connection of a third upper arm switch and a third lower arm switch; a series connection of an upper arm rectifier and a lower arm rectifier; a high-potential-side path electrically connecting the high-potential-side terminals of the first, second, and third upper-arm switches, the high-potential-side terminal of the upper-arm rectifier unit, and the high-potential-side DC terminal; a low potential side path electrically connecting the low potential side terminals of the first, second, and third lower arm switches, the low potential side terminal of the lower arm rectifier unit, and the low potential side DC terminal; a first inductor electrically connecting a connection point between the first upper arm switch and the first lower arm switch and the first AC terminal; a second inductor electrically connecting a connection point between the second upper arm switch and the second lower arm switch and the second AC terminal; a third inductor electrically connecting a connection point between the third upper arm switch and the third lower arm switch and the third AC terminal; a connection path that electrically connects a connection point between the upper arm rectifier and the lower arm rectifier and the fourth AC terminal; a DC side storage unit that electrically connects the high potential side path and the low potential side path; a series connection of a compensation storage unit and a compensation switch that electrically connects the high potential side path or the low potential side path to the third AC terminal; a first single-phase charging switch provided in the connection path; a second single-phase charging switch that electrically connects the first AC terminal and the second AC terminal; A control unit; Equipped with When the control unit determines that the single-phase AC power supply is connected to the first AC terminal and the fourth AC terminal, with the compensation switch, the first single-phase charging switch, and the second single-phase charging switch turned on, the control unit controls the switching of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch to convert the AC power input from the first AC terminal and the fourth AC terminal into DC power and output it from the high potential side DC terminal and the low potential side DC terminal, and also controls the switching of the third upper arm switch and the third lower arm switch to reduce pulsation in the DC power output from the high potential side DC terminal and the low potential side DC terminal due to charging and discharging of the compensation storage unit.

[0011] In the present invention, during power conversion using a single-phase AC power supply, the second single-phase charging switch is turned on, and the first and second inductors can be used as a power transmission path, thereby increasing the DC power output from the high-potential side DC terminal and the low-potential side DC terminal.

[0012] Furthermore, in the present invention, during power conversion using a single-phase AC power supply, the compensation switch is turned on, and the high-potential side path or the low-potential side path is electrically connected to the third AC terminal via the compensation storage unit. In this case, the compensation storage unit can charge and discharge an electric charge so as to absorb pulsation in the DC power. With the compensation switch turned on, the control unit performs switching control of the third upper arm switch and the third lower arm switch to reduce pulsation in the DC power output from the high-potential side DC terminal and the low-potential side DC terminal due to charging and discharging of the compensation storage unit. As a result, during power conversion using a single-phase AC power supply, it is possible to reduce pulsation in the DC power while increasing the output DC power. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a diagram showing the overall configuration of an on-board charger according to a first embodiment; [Figure 2] FIG. 1 shows an on-board charger connected to a three-phase AC power supply. [Figure 3] 1 is a diagram showing an on-board charger connected to a single-phase AC power supply; [Figure 4] 4 is a flowchart showing a procedure for controlling charging of a storage battery. [Figure 5] Block diagram of three-phase charging control processing. [Figure 6] 4 is a time chart showing the changes in current, voltage, etc. during three-phase charging control. [Figure 7] Block diagram of single-phase charging control processing. [Figure 8] 4 is a time chart showing the transition of current, voltage, etc. during single-phase charging control. [Figure 9] 10 is a time chart relating to a pulsation reduction process according to the second embodiment. [Figure 10] 10 is a time chart showing interleaved driving according to a third embodiment. [Figure 11] 6 is a time chart showing a switching mode and the like according to a comparative example; [Figure 12] FFT analysis results showing the effect of reducing current ripple. [Figure 13]FIG. 10 is a diagram illustrating the overall configuration of an on-board charger according to another embodiment. [Figure 14] FIG. 10 is a diagram illustrating the overall configuration of an on-board charger according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] Several embodiments will be described with reference to the drawings. In several embodiments, functionally and / or structurally corresponding and / or associated parts may be assigned the same reference numerals or reference numerals that differ in the hundredth or more digit. For corresponding and / or associated parts, reference may be made to the descriptions of other embodiments.

[0015] First Embodiment A first embodiment of a power conversion device according to the present invention will be described below with reference to the drawings. The power conversion device according to this embodiment is provided in a vehicle such as an electric vehicle, and specifically, is an AC-DC converter constituting an on-board charger. The on-board charger is also called an on-board charger.

[0016] The power conversion device has an AC terminal and a DC terminal. The power conversion device has a function of converting AC power input via the AC terminal connected to an AC power source external to the vehicle into DC power and outputting it from the DC terminal. The DC power output from the DC terminal is supplied to a storage battery provided in the vehicle. The power conversion device also has a function of converting DC power input via the DC terminal into AC power and outputting it from the AC terminal. The AC power output from the AC terminal is supplied to an external power system via the external AC power source. The power conversion device can be connected to a three-phase AC power source or a single-phase AC power source.

[0017] As shown in Fig. 1, the power conversion device 10 includes a first AC terminal Tac1, a second AC terminal Tac2, a third AC terminal Tac3, and a fourth AC terminal Tac4 as AC terminals. Of the first to fourth AC terminals Tac1 to Tac4, the first to third AC terminals Tac1 to Tac3 are connectable to an external three-phase AC power supply 21, as shown in Fig. 2. Of the first to fourth AC terminals Tac1 to Tac4, the first and fourth AC terminals Tac1 and Tac4 are connectable to an external single-phase AC power supply 22, as shown in Fig. 3.

[0018] The power conversion device 10 has a high-potential side DC terminal TdcH and a low-potential side DC terminal TdcL as DC terminals. The high-potential side DC terminal TdcH and the low-potential side DC terminal TdcL are connected to an input section of a DC-DC converter 24 constituting an on-board charger. The output section of the DC-DC converter 24 is connected to a chargeable and dischargeable storage battery 20 mounted on the vehicle. The DC-DC converter 24 transforms a DC voltage input from the high-potential side DC terminal TdcH and the low-potential side DC terminal TdcL and supplies the transformed DC voltage to the storage battery 20. The DC-DC converter 24 also transforms a DC voltage input from the storage battery 20 and supplies the transformed DC voltage to the high-potential side DC terminal TdcH and the low-potential side DC terminal TdcL. The DC-DC converter 24 is, for example, an isolated DC-DC converter whose input section and output section are electrically insulated from each other and includes a transformer connecting the input section and the output section.

[0019] The power conversion device 10 includes four upper and lower arm switches for four phases: a series connection of a first upper arm switch S1H and a first lower arm switch S1L, a series connection of a second upper arm switch S2H and a second lower arm switch S2L, a series connection of a third upper arm switch S3H and a third lower arm switch S3L, and a series connection of a fourth upper arm switch S4H and a fourth lower arm switch S4L. In this embodiment, each of the upper and lower arm switches S1H to S4L is an N-channel MOSFET having a body diode. Therefore, in each of the upper and lower arm switches S1H to S4L, the high-potential side terminal is the drain and the low-potential side terminal is the source. Of the first to third phases, for example, the first phase is the U-phase, the second phase is the V-phase, and the third phase is the W-phase. The fourth upper arm switch S4H corresponds to the "upper arm rectifier" and the fourth lower arm switch S4L corresponds to the "lower arm rectifier."

[0020] The power conversion device 10 includes a high-potential-side path 30H that is an electrical path connecting high-potential-side terminals of the first, second, third, and fourth upper-arm switches S1H, S2H, S3H, and S4H to a high-potential-side DC terminal TdcH, and a low-potential-side path 30L that is an electrical path connecting low-potential-side terminals of the first, second, third, and fourth lower-arm switches S1L, S2L, S3L, and S4L to a low-potential-side DC terminal TdcL. The high-potential-side path 30H and the low-potential-side path 30L are conductive members such as bus bars.

[0021] The power conversion device 10 includes a DC-side capacitor 34 that connects the high-potential-side path 30H and the low-potential-side path 30L. The DC-side capacitor 34 functions as a smoothing capacitor and is, for example, an electrolytic capacitor.

[0022] The power conversion device 10 includes a first path 41, a second path 42, and a third path 43. The first path 41 is an electrical path connecting the low potential side terminal of the first upper arm switch S1H and the high potential side terminal of the first lower arm switch S1L with the first AC terminal Tac1. The second path 42 is an electrical path connecting the low potential side terminal of the second upper arm switch S2H and the high potential side terminal of the second lower arm switch S2L with the second AC terminal Tac2. The third path 43 is an electrical path connecting the low potential side terminal of the third upper arm switch S3H and the high potential side terminal of the third lower arm switch S3L with the third AC terminal Tac3.

[0023] The power conversion device 10 includes a first inductor 31 provided in a first path 41, a second inductor 32 provided in a second path 42, and a third inductor 33 provided in a third path 43. In this embodiment, the inductors 31 to 33 have the same specifications. Therefore, the inductors 31 to 33 have the same inductance value. Furthermore, the inductors 31 to 33 have the same rated current (specifically, temperature rise rated current).

[0024] The power conversion device 10 includes a connection path 44, which is an electrical path connecting the low potential side terminal of the fourth upper arm switch S4H and the high potential side terminal of the fourth lower arm switch S4L with the fourth AC terminal Tac4. The power conversion device 10 also includes a first single-phase charging switch 45 provided in the connection path 44. The first single-phase charging switch 45 allows bidirectional current flow when turned on and prevents bidirectional current flow when turned off.

[0025] The power conversion device 10 includes a second single-phase charging switch 46. The second single-phase charging switch 46 connects a portion of the first path 41 closer to the first AC terminal Tac1 than the first inductor 31 to a portion of the second path 42 closer to the second AC terminal Tac2 than the second inductor 32. The second single-phase charging switch 46 allows bidirectional current flow when turned on and blocks bidirectional current flow when turned off. Note that the second single-phase charging switch 46 may connect the first AC terminal Tac1 and the second AC terminal Tac2, for example.

[0026] The power conversion device 10 includes a series connection of a compensation capacitor 47 and a compensation switch 48 as a configuration for reducing pulsation in the DC power output from each of the DC terminals TdcH and TdcL. The series connection of the compensation capacitor 47 and the compensation switch 48 connects the high potential side path 30H and a portion of the third path 43 closer to the third AC terminal Tac3 than the third inductor 33. The compensation capacitor 47 is, for example, a film capacitor. The compensation switch 48 allows bidirectional current flow when turned on and blocks bidirectional current flow when turned off. The series connection of the compensation capacitor 47 and the compensation switch 48 may connect the high potential side path 30H and the third AC terminal Tac3. The compensation capacitor 47 may also be located closer to the high potential side path 30H than the compensation switch 48.

[0027] The power conversion device 10 includes a DC-side voltage sensor 50, an AC-side voltage sensor 51, and a compensation voltage sensor 52. The DC-side voltage sensor 50 detects the terminal voltage of the DC-side capacitor 34, the AC-side voltage sensor 51 detects the voltage difference between the first AC terminal Tac1 and the fourth AC terminal Tac4, and the compensation voltage sensor 52 detects the terminal voltage of the compensation capacitor 47.

[0028] The power conversion device 10 includes first to third current sensors 61 to 63. The first current sensor 61 detects the current flowing through the first inductor 31, the second current sensor 62 detects the current flowing through the second inductor 32, and the third current sensor 63 detects the current flowing through the third inductor 33. The detected values ​​of the sensors 50 to 52 and 61 to 63 are input to a control device 70 serving as a control unit included in the power conversion device 10.

[0029] The control device 70 is mainly composed of a microcomputer 71, which includes a CPU. The functions provided by the microcomputer 71 can be provided by software stored in a physical memory device and a computer executing the software, software alone, hardware alone, or a combination thereof. For example, if the microcomputer 71 is provided by a hardware electronic circuit, the function can be provided by a digital circuit including multiple logic circuits or an analog circuit. For example, the microcomputer 71 executes a program stored in a non-transitory tangible storage medium serving as a storage unit of the microcomputer 71. The program includes, for example, programs for the processes shown in Figures 4, 5, and 7 (described below). Execution of the program results in the execution of a method corresponding to the program. The storage unit is, for example, a non-volatile memory. The program stored in the storage unit can be updated via a communication network such as the Internet, for example, via OTA (Over The Air) or other means.

[0030] The control device 70 performs three-phase charging control or single-phase charging control. The charging control will be described below with reference to the flowchart of FIG.

[0031] In step S10, it is determined whether a command for three-phase charging control has been issued. In this embodiment, as shown in Fig. 2, if it is determined that a three-phase AC power supply 21 is connected to the first to third AC terminals Tac1 to Tac3, it is determined that a command for three-phase charging control has been issued. In the three-phase AC power supply 21, the amplitude and frequency of the output voltages of the three phases are the same, and the phases of the output voltages and output currents are shifted by 120° for each phase. Note that, although the neutral point of the three-phase AC power supply 21 is connected to the fourth AC terminal Tac4 in Fig. 2, the neutral point does not have to be connected to the fourth AC terminal Tac4.

[0032] If the determination in step S10 is affirmative, three-phase charging control is performed in steps S11 and S12. Specifically, in step S11, the first single-phase charging switch 45, the second single-phase charging switch 46, and the compensation switch 48 are turned off. Also, the fourth upper arm switch S4H and the fourth lower arm switch S4L are turned off.

[0033] In step S12, the first, second, and third upper-arm switches S1H, S2H, and S3H and the first, second, and third lower-arm switches S1L, S2L, and S3L are switched on alternately with dead times between them, so that AC power input from the first AC terminal Tac1, the second AC terminal Tac2, and the third AC terminal Tac3 is converted into DC power and output from the high-potential side DC terminal TdcH and the low-potential side DC terminal TdcL. In each phase, the upper and lower arm switches are alternately turned on with dead times between them. In each phase, the upper and lower arm switches have the same switching period.

[0034] If the determination in step S10 is negative, the process proceeds to step S13, where it is determined whether or not a command for single-phase charging control has been issued. In this embodiment, as shown in FIG. 3 , if it is determined that the single-phase AC power supply 22 is connected to the first AC terminal Tac1 and the fourth AC terminal Tac4, it is determined that a command for single-phase charging control has been issued. In this embodiment, the amplitude of the output voltage of the single-phase AC power supply 22 is the same as the amplitude of the output voltage of the three-phase AC power supply 21. In addition, the frequency of the output voltage of the single-phase AC power supply 22 is the same as the frequency of the output voltage of the three-phase AC power supply 21.

[0035] If the determination in step S13 is affirmative, single-phase charging control is performed in steps S14 and S15. Specifically, in step S14, the first single-phase charging switch 45, the second single-phase charging switch 46, and the compensation switch 48 are turned on.

[0036] In step S15, the first upper arm switch S1H, the first lower arm switch S1L, the second upper arm switch S2H, and the second lower arm switch S2L are switched on in order to convert the AC power input from the first AC terminal Tac1 and the fourth AC terminal Tac4 into DC power and output it from the high potential side DC terminal TdcH and the low potential side DC terminal TdcL. In each phase, the upper arm switches and the lower arm switches are alternately turned on in synchronization with each other with dead time therebetween. In each phase, one switching cycle of the upper and lower arm switches is the same, which is the same as one switching cycle during three-phase charging control.

[0037] Furthermore, in order to reduce pulsation in the DC power output from the high potential side DC terminal TdcH and the low potential side DC terminal TdcL, the third upper arm switch S3H and the third lower arm switch S3L are switched on alternately with dead time therebetween. The third upper arm switch S3H and the third lower arm switch S3L have the same switching period, which is also the same as the first and second upper and lower arm switches S1H, S1L, S2H, S2L.

[0038] In step S15, the fourth lower arm switch S4L is turned on and the fourth upper arm switch S4H is turned off during a first period in which a current flows from the fourth AC terminal Tac4 to the first AC terminal Tac1 via the single-phase AC power supply 22. On the other hand, during a second period in which a current flows from the first AC terminal Tac1 to the fourth AC terminal Tac4 via the single-phase AC power supply 22, the fourth upper arm switch S4H is turned on and the fourth lower arm switch S4L is turned off. Whether the current timing falls within the first period or the second period may be determined based on, for example, a detection value of the first current sensor 61.

[0039] One switching period Tsw4 of the fourth upper and lower arm switches S4H and S4L is the same as one period of the output voltage of the single-phase AC power supply 22 and is longer than one switching period Tsw1, Tsw2, and Tsw3 of the first, second, and third upper and lower arm switches S1H, S1L, S2H, S2L, S3H, and S3L. This is because, for the first to third phases, high-frequency switching (e.g., tens of kHz to hundreds of kHz) is required to reduce ripple in the current flowing through the inductors 31 to 33, while for the fourth phase, switching at a frequency equivalent to the fundamental frequency (e.g., 50 Hz or 60 Hz) of the output voltage of the single-phase AC power supply 22 is sufficient. For this reason, in this embodiment, the fourth upper and lower arm switches S4H and S4L are semiconductor switching elements with longer turn-on and turn-off times than the first to third upper and lower arm switches S1H, S1L, S2H, S2L, S3H, and S3L. This eliminates the need to use high-performance switches as the fourth upper and lower arm switches S4H and S4L, and the cost of the power conversion device 10 can be reduced.

[0040] During single-phase charging control, when DC power input from each DC terminal TdcH, TdcL is converted into AC power and output from AC terminals Tac1, Tac4 by switching control of the first upper and lower arm switches S1H, S1L and the second upper and lower arm switches S2H, S2L, in step S15, the fourth upper arm switch S4H is turned on and the fourth lower arm switch S4L is turned off during a first period in which current flows from the fourth AC terminal Tac4 to the first AC terminal Tac1 via the single-phase AC power supply 22. On the other hand, during a second period in which current flows from the first AC terminal Tac1 to the fourth AC terminal Tac4 via the single-phase AC power supply 22, the fourth lower arm switch S4L is turned on and the fourth upper arm switch S4H is turned off.

[0041] Next, the three-phase charging control will be described with reference to Fig. 5. Fig. 5 is a block diagram of the three-phase charging control executed by the control device 70. A voltage control unit 80 calculates a d-axis target current Idref for controlling the terminal voltage of the DC side capacitor 34 detected by the DC side voltage sensor 50 (hereinafter referred to as the DC voltage detection value Vdcr) to the target DC voltage Vdcref. More specifically, the voltage control unit 80 includes a voltage deviation calculation unit 81 and a voltage feedback control unit 82. The voltage deviation calculation unit 81 calculates a voltage deviation ΔV by subtracting the DC voltage detection value Vdcr from the target DC voltage Vdcref. The target DC voltage Vdcref may be set based on the rated voltages of the upper and lower arm switches S1H to S4L and the DC-DC converter 24, for example.

[0042] The voltage feedback control unit 82 calculates the d-axis target current Idref as a manipulated variable for feedback controlling the voltage deviation ΔV to 0. The feedback control in the voltage feedback control unit 82 is, for example, proportional-integral control.

[0043] The electrical angle calculation unit 83 calculates the electrical angle θe based on the voltage detected by the AC-side voltage sensor 51 (hereinafter referred to as the detected AC voltage value V1r). In this embodiment, the electrical angle θe at the zero-cross timing (specifically, for example, the zero-upcross timing) of the detected AC voltage value V1r is set to 0°, and the electrical angle θe at the next zero-upcross timing is set to 360°. As a result, one cycle of the detected AC voltage value V1r corresponds to one electrical angle cycle (0° to 360°). In this embodiment, the detected AC voltage value V1r is set to positive when the voltage at the first AC terminal Tac1 is higher than the voltage at the fourth AC terminal Tac4.

[0044] The two-phase conversion unit 84 converts the first, second, and third current detection values ​​i1r, i2r, and i3r in the three-phase fixed coordinate system into d- and q-axis currents Idr and Iqr in the two-phase rotating coordinate system (dq-axis coordinate system) based on the currents detected by the first, second, and third current sensors 61, 62, and 63 (hereinafter referred to as first, second, and third current detection values ​​i1r, i2r, and i3r) and the electrical angle θe. In this embodiment, the first, second, and third current detection values ​​i1r, i2r, and i3r are defined as positive when they flow from the first, second, and third AC terminals Tac1, Tac2, and Tac3 toward the first, second, and third inductors 31, 32, and 33.

[0045] The current control unit 85 includes a d-axis deviation calculation unit 86 , a d-axis feedback control unit 87 , a q-axis deviation calculation unit 88 , and a q-axis feedback control unit 89 .

[0046] A d-axis deviation calculation unit 86 calculates a d-axis current deviation ΔId by subtracting the d-axis current Idr from the d-axis target current Idref. A d-axis feedback control unit 87 calculates a d-axis target voltage Vdref as a manipulated variable for feedback controlling the d-axis current deviation ΔId to zero. The feedback control in the d-axis feedback control unit 87 is, for example, proportional-integral control.

[0047] The q-axis deviation calculation unit 88 calculates the q-axis current deviation ΔIq by subtracting the q-axis current Iqr from the q-axis target current Iqref. The q-axis target current Iqref is a target value of the reactive current, and in this embodiment, is set to 0 to make the power factor 1. Making the power factor 1 means making the phase difference between the first, second, and third output voltages V1, V2, and V3 of the three-phase AC power supply 21 and the first, second, and third detected current values ​​i1r, i2r, and i3r zero. The q-axis feedback control unit 89 calculates the q-axis target voltage Vqref as a manipulated variable for feedback-controlling the q-axis current deviation ΔIq to zero. The feedback control in the q-axis feedback control unit 89 is, for example, proportional-integral control.

[0048] The three-phase conversion unit 90 converts the d- and q-axis target voltages Vdref, Vqref in the two-phase rotating coordinate system into first, second, and third target voltages Vleg1ref, Vleg2ref, and Vleg3ref in the three-phase fixed coordinate system based on the d- and q-axis target voltages Vdref, Vqref and the electrical angle θe. The first, second, and third target voltages Vleg1ref, Vleg2ref, and Vleg3ref are sinusoidal signals whose phases are shifted by 120° in electrical angle increments. The sinusoidal signals become 0 every 180° of electrical angle.

[0049] The PWM generating unit 91 generates first upper and lower arm drive signals to be supplied to the gates of the first upper and lower arm switches S1H and S1L, second upper and lower arm drive signals to be supplied to the gates of the second upper and lower arm switches S2H and S2L, and third upper and lower arm drive signals to be supplied to the gates of the third upper and lower arm switches S3H and S3L by pulse width modulation (PWM) based on a magnitude comparison between the first, second, and third target voltages Vleg1ref, Vleg2ref, and Vleg3ref and a carrier signal. The carrier signal is, for example, a triangular wave signal, and one cycle of the carrier signal is sufficiently shorter than one electrical angle cycle (0° to 360°). Within one electrical angle cycle, the switching patterns of the first upper and lower arm switches S1H and S1L, the second upper and lower arm switches S2H and S2L, and the third upper and lower arm switches S3H and S3L are shifted in phase by 120°.

[0050] 6 shows the trends of the first, second, and third output voltages V1, V2, and V3 of the three-phase AC power supply 21, the first, second, and third detected current values ​​i1r, i2r, and i3r, the sum of the first, second, and third DC powers P1, P2, and P3, and the DC power Pdc output from each DC terminal TdcH and TdcL during three-phase charging control. The first, second, and third output voltages V1, V2, and V3 are positive when the voltages at the first, second, and third AC terminals Tac1, Tac2, and Tac3 are higher than the voltage at the neutral point of the three-phase AC power supply 21. The first, second, and third DC powers P1, P2, and P3 are individual DC powers output from the three-phase AC power supply 21 via the first, second, and third inductors 31, 32, and 33, respectively, from the DC terminals TdcH and TdcL.

[0051] In the example shown in FIG. 6, the frequency of the output voltages V1 to V3 of the three-phase AC power supply 21 is 50 Hz, and the target DC voltage Vdcref is set to 800 V.

[0052] As shown in FIG. 6, three-phase charging control is executed so that the phase difference between the first, second, and third output voltages V1, V2, and V3 and the first, second, and third current detection values ​​i1r, i2r, and i3r is 0 (i.e., the power factor is 1).

[0053] In this embodiment, during three-phase charging control, the first, second, and third target voltages Vleg1ref, Vleg2ref, and Vleg3ref are calculated in the three-phase conversion unit 90 so that the first DC power P1, the second DC power P2, and the third DC power P3 are equal to each other. As a result, in the example shown in Fig. 6, the effective value of the current flowing through the first, second, and third inductors 31, 32, and 33 is 16 Arms.

[0054] Incidentally, the control device 70 may perform switching control of the upper and lower arm switches S1H to S3L of the first to third phases based on average current mode control or the like as the three-phase charging control, instead of the control shown in FIG.

[0055] Next, the single-phase charging control will be described with reference to Fig. 7. Fig. 7 is a block diagram of the single-phase charging control executed by the control device 70.

[0056] The control device 70 includes a charge control section 100 for power transmission, and a pulsation reduction control section 120 for reducing pulsation in the DC power.

[0057] In the charging control unit 100, the filter unit 112 performs low-pass filtering on the DC voltage detection value Vdcr, thereby removing harmonic components of the output voltage of the single-phase AC power supply 22 that are included in the DC voltage detection value Vdcr. The harmonic components are, for example, components of a secondary frequency (e.g., 100 Hz or 120 Hz) of the output voltage.

[0058] The voltage control unit 101 includes a voltage deviation calculation unit 102 and a voltage feedback control unit 103. The voltage deviation calculation unit 102 calculates a voltage deviation ΔV by subtracting the DC voltage detection value Vdcr from the target DC voltage Vdcref, from which harmonic components have been removed by the filter unit 112. The voltage feedback control unit 103 calculates a target current amplitude Iampref as a manipulated variable for feedback control to adjust the voltage deviation ΔV to zero. The feedback control in the voltage feedback control unit 103 is, for example, proportional-integral control.

[0059] The electrical angle calculation unit 83 calculates the electrical angle θe based on the AC voltage detection value V1r. The sine wave generation unit 109 generates a sine wave signal "sin×θe" based on the electrical angle θe.

[0060] The current control unit 105 includes a target current calculation unit 106, a current deviation calculation unit 107, and a current feedback control unit .

[0061] The target current calculation unit 106 calculates the target current Iacref by multiplying the target current amplitude Iampref by the sine wave signal "sin×θe." The target current Iacref fluctuates with the same period as the AC voltage detection value V1r.

[0062] The current deviation calculation unit 107 calculates the current deviation ΔI by subtracting the sum of the first current detection value i1r and the second current detection value i2r from the target current Iacref. The sum of the first current detection value i1r and the second current detection value i2r is calculated by the current adder 110.

[0063] The current feedback control unit 108 calculates first and second target voltages Vleg1ref, Vleg2ref as manipulated variables for feedback control of the current deviation ΔI to zero. The feedback control in the current feedback control unit 108 is, for example, proportional-integral control. The first and second target voltages Vleg1ref, Vleg2ref are signals of the same phase. In this embodiment, during single-phase charging control, the current feedback control unit 108 calculates the first and second target voltages Vleg1ref, Vleg2ref so that the first DC power P1 and the second DC power P2 are equal.

[0064] The first PWM generation unit 111 generates first upper and lower arm drive signals to be supplied to the gates of the first upper and lower arm switches S1H and S1L and second upper and lower arm drive signals to be supplied to the gates of the second upper and lower arm switches S2H and S2L by pulse width modulation based on a magnitude comparison between the first and second target voltages Vleg1ref and Vleg2ref and a carrier signal. In this embodiment, the phase difference between the switching pattern of the first upper and lower arm switches S1H and S1L and the switching pattern of the second upper and lower arm switches S2H and S2L is 0° over one electrical angle cycle. In other words, the on-switching timings and off-switching timings of the first upper arm switch S1H and the second upper arm switch S2H are synchronized, and the on-switching timings and off-switching timings of the first lower arm switch S1L and the second lower arm switch S2L are synchronized.

[0065] Here, when a three-phase AC power supply 21 is connected to the first AC terminal Tac1, the second AC terminal Tac2, and the third AC terminal Tac3, the maximum value of the DC power output from the high potential side DC terminal TdcH and the low potential side DC terminal TdcL is defined as Pdcmax. The charging control unit 100 generates the first upper and lower arm drive signals and the second upper and lower arm drive signals so that the maximum value of the DC power output from the high potential side DC terminal TdcH and the low potential side DC terminal TdcL during single-phase charging control is equal to or less than Pdcmax×2 / 3. Specifically, for example, the voltage feedback control unit 103 calculates the target current amplitude Iampref so that the maximum value of the DC power output from the high potential side DC terminal TdcH and the low potential side DC terminal TdcL during single-phase charging control is equal to or less than Pdcmax×2 / 3.

[0066] This allows the maximum current flowing through the first and second inductors 31, 32 during single-phase charging control to be equal to or less than the maximum current flowing through the first and second inductors 31, 32 during three-phase charging control. As a result, the rated currents (specifically, temperature rise rated currents) of the first, second, and third inductors 31, 32, and 33 can be reduced, allowing the first, second, and third inductors 31, 32, and 33 to be made smaller.

[0067] Next, the pulsation reduction control section 120 will be described.

[0068] In the pulsation reduction control unit 120, a target compensation voltage calculation unit 121 calculates a target compensation voltage Vcpref, which is a target value of the terminal voltage of the compensation capacitor 47 for reducing pulsation of the DC power Pdc. Specifically, the target compensation voltage calculation unit 121 calculates the target compensation voltage Vcpref based on the pulsation compensation amplitude Ppeak, the electrical angle θe, and the following equation (eq1):

[0069]

number

[0070] The voltage control unit 122 includes a compensation voltage deviation calculation unit 123 and a compensation voltage feedback control unit 124. The compensation voltage deviation calculation unit 123 calculates a compensation voltage deviation ΔVp by subtracting the voltage detected by the compensation voltage sensor 52 (hereinafter referred to as the compensation voltage detection value Vcpr) from the target compensation voltage Vcpref. The compensation voltage feedback control unit 124 calculates a target feedback current I3fb as a manipulated variable for feedback controlling the compensation voltage deviation ΔVp to zero. The feedback control in the compensation voltage feedback control unit 124 is, for example, proportional-integral control.

[0071] The feedforward current calculation unit 125 calculates the target feedforward current I3ff based on the pulsation compensation amplitude Ppeak, the electrical angle θe, and the following equation (eq2).

[0072]

number

[0073] The current control unit 126 includes an adder 127, a compensation current deviation calculation unit 128, and a compensation current feedback control unit 129. The adder 127 calculates the target compensation current I3ref by adding the target feedforward current I3ff to the target feedback current I3fb. Note that the feedforward current calculation unit 125 is not essential. In this case, "I3ref = I3fb".

[0074] A compensation current deviation calculation unit 128 calculates a compensation current deviation ΔIp by subtracting the third current detection value i3r from the target compensation current I3ref. A compensation current feedback control unit 129 calculates a third target voltage Vleg1ref3 as a manipulated variable for feedback control of the compensation current deviation ΔIp to 0. The feedback control in the compensation current feedback control unit 129 is, for example, proportional-integral control.

[0075] The second PWM generating unit 130 generates third upper and lower arm drive signals to be supplied to the gates of the third upper and lower arm switches S3H and S3L by pulse width modulation based on a comparison of the magnitude between the third target voltage Vleg3ref and the carrier signal.

[0076] 8 shows the changes in the compensation voltage detection value Vcpr, the output voltage Vac and output current iac of the single-phase AC power supply 22, the current icpr flowing through the compensation capacitor 47, the first and second current detection values ​​i1r and i2r, the output power Pac of the single-phase AC power supply 22, the power Pcpr (=Vcpr×icpr) of the compensation capacitor 47, and the DC power Pdc output from each DC terminal TdcH, TdcL during single-phase charging control. The compensation voltage detection value Vcpr is considered positive when the voltage across the compensation capacitor 47 on the compensation switch 48 side is higher than the voltage across the third path 43 side. The output voltage Vac of the single-phase AC power supply 22 is considered positive when the voltage across the first AC terminal Tac1 is higher than the voltage across the fourth AC terminal Tac4 side. The output current iac of the single-phase AC power supply 22 is considered positive when it flows from the fourth AC terminal Tac4 side to the first AC terminal Tac1 side. The current icpr flowing through the compensation capacitor 47 is positive when it flows from the third path 43 side to the compensation switch 48 side of both ends of the compensation capacitor 47.

[0077] 8, the frequency of the output voltage Vac of the single-phase AC power supply 22 is 50 Hz, the effective value of the output voltage Vac is 230 Vrms, and the target DC voltage Vdcref is set to 800 V. In addition, the DC power Pdc is set to a value that is two-thirds of the DC power Pdc during three-phase charging control.

[0078] By high-frequency switching control of the first and second upper and lower arm switches S1H, S1L, S2H, S2L and 50 Hz switching control of the fourth upper and lower arm switches S4H, S4L, single-phase charging control is executed so that the phase difference between the output voltage Vac of the single-phase AC power supply 22 and the first and second current detection values ​​i1r, i2r becomes 0 (i.e., the power factor becomes 1), as shown in FIG. 8.

[0079] In this embodiment, during single-phase charging control, the first and second target voltages Vleg1ref and Vleg2ref are calculated so that the first DC power P1 and the second DC power P2 are equal to each other. Therefore, in the example shown in Fig. 8, the effective value of the current flowing through the first and second inductors 31 and 32 is 16 Arms.

[0080] 8, the output power Pac of the single-phase AC power supply 22 (i.e., the input power of the power conversion device 10) pulsates at a frequency twice the fundamental frequency of the output voltage Vac of the single-phase AC power supply 22, and pulsates with an amplitude of 7360 W centered around 7360 W. The third upper and lower arm switches S3H and S3L are switched and controlled so that the compensation voltage detection value Vcpr is controlled to a target compensation voltage Vcpref that reduces this pulsating component. As a result, the pulsating component of the input power is absorbed as reactive power by the compensation capacitor 47, and the DC power Pdc transmitted to each DC terminal TdcH and TdcL becomes constant at approximately 7360 W. As a result, the capacitance of the DC-side capacitor 34 can be reduced, and the DC-side capacitor 34 can be made smaller.

[0081] According to the present embodiment described above in detail, during single-phase charging control, it is possible to reduce the pulsation of the DC power Pdc while increasing the DC power Pdc output from the power conversion device 10.

[0082] <Modification of the first embodiment> The charging control unit 100 may calculate the target current amplitude Iampref so that the maximum value of the DC power output from the high potential side DC terminal TdcH and the low potential side DC terminal TdcL during single-phase charging control is greater than Pdcmax / 3 and less than Pdcmax×2 / 3.

[0083] Second Embodiment The second embodiment will be described below with reference to the drawings, focusing on differences from the first embodiment. In this embodiment, a method for setting the target compensation voltage Vcpref in the pulsation reduction control unit 120 is changed. This setting method will be described below with reference to FIG. 9. FIG. 9 shows calculation results for the terminal voltage of the compensation capacitor 47 and the current flowing through the compensation capacitor 47 when the amplitude (7360 W is used as an example) of the pulsating power Pcpr absorbed by the compensation capacitor 47 is kept constant and the time average value (hereinafter referred to as the voltage average value) of the terminal voltage of the compensation capacitor 47 over one cycle of the output voltage Vac is changed. The pulsating power Pcpr shown in FIG. 9 pulsates around zero at a frequency twice the fundamental frequency of the output voltage Vac of the single-phase AC power supply 22.

[0084] 9, Vca is the target compensation voltage Vcpref in the first embodiment. One cycle of the target compensation voltage Vcpref in the first embodiment is the same as half the cycle of the output voltage Vac, and it becomes 0 every half cycle of the output voltage Vac. Vaave is the average voltage value of Vca, and Vap is the peak value of Vca in one cycle of the output voltage Vac.

[0085] Vcb is the target compensation voltage when the average voltage is higher than Vca, and Vbave is the average voltage of Vcb. Furthermore, Vcc is the target compensation voltage when the average voltage is higher than Vcb, and Vcd is the target compensation voltage when the average voltage is higher than Vcc. Each cycle of Vcb, Vcc, and Vcd is the same as half the cycle of the output voltage Vac, and they reach a peak value every half cycle of the output voltage Vac and a minimum value every half cycle of the output voltage Vac.

[0086] ica is the current that flows through the compensation capacitor 47 when the target compensation voltage is Vca, icb is the current that flows through the compensation capacitor 47 when the target compensation voltage is Vcb, icc is the current that flows through the compensation capacitor 47 when the target compensation voltage is Vcc, and icd is the current that flows through the compensation capacitor 47 when the target compensation voltage is Vcd.

[0087] By increasing the average voltage value of the compensation capacitor 47, the peak value of the target compensation voltage increases slightly, while the voltage ripple of the target compensation voltage and the current ripple flowing through the compensation capacitor 47 become smaller. Therefore, the target compensation voltage calculation unit 121 calculates a target compensation voltage Vcpref whose average voltage value of the target compensation voltage is higher than Vaave, on the condition that the peak value of the target compensation voltage is equal to or less than the allowable upper limit voltage Vlim of the compensation capacitor 47. In the example shown in Fig. 9, Vcb or Vcc is a candidate for the target compensation voltage Vcpref.

[0088] Here, the value of "Vap / Vaave" corresponding to Vca is π / 2. For a target compensation voltage whose average voltage value is higher than Vaave, the "peak value of the target compensation voltage Vcpref in one cycle of the output voltage Vac / average voltage value of the target compensation voltage Vcpref" is smaller than π / 2. Therefore, the target compensation voltage calculation unit 121 calculates the target compensation voltage Vcpref such that the peak value of the terminal voltage of the compensation capacitor 47 in one cycle of the output voltage Vac of the single-phase AC power supply 22 is smaller than the value obtained by multiplying the time average value of the terminal voltage of the compensation capacitor 47 in one cycle of the output voltage Vac by π / 2. The target compensation voltage calculation unit 121 may calculate the target compensation voltage Vcpref based on map information in which the target compensation voltage Vcpref is defined in association with the pulsation compensation amplitude Ppeak and the electrical angle θe.

[0089] In this case, the feedforward current calculation unit 125 may calculate the target feedforward current I3ff corresponding to the target compensation voltage Vcpref. For example, if Vcc in FIG. 9 is calculated as the target compensation voltage Vcpref, the feedforward current calculation unit 125 may calculate icc in FIG. 9 as the target feedforward current I3ff. The feedforward current calculation unit 125 may calculate the target feedforward current I3ff based on map information in which the target feedforward current I3ff is defined in association with the pulsation compensation amplitude Ppeak and the electrical angle θe. As in the first embodiment, the feedforward current calculation unit 125 is not essential.

[0090] The target compensation voltage Vcpref in the first embodiment can reduce the peak value of the terminal voltage of the compensation capacitor 47, but increases the ripples of the terminal voltage and current of the compensation capacitor 47. In contrast, according to the present embodiment, the ripples of the terminal voltage and current can be reduced, and the compensation capacitor 47 can be made smaller. Furthermore, the rated current of each of the inductors 31 to 33 can also be reduced, and the inductors 31 to 33 can be made smaller.

[0091] Third Embodiment The third embodiment will be described below with reference to the drawings, focusing on differences from the first embodiment. In this embodiment, the control device 70 performs interleaved driving of the first and second upper and lower arm switches S1H, S1L, S2H, and S2L during single-phase charging control, as shown in FIG. 10. The interleaved driving in this embodiment is switching control in which the timing at which the first upper arm switch S1H is turned on and the timing at which the second upper arm switch S2H is turned on are shifted by 180 electrical degrees. FIG. 10 also shows the transitions of the first and second current detection values ​​i1r and i2r and the current flowing through the DC-side capacitor 34 in the case of interleaved driving. FIG. 11 shows, as a comparative example, the switching control of the first embodiment without interleaved driving.

[0092] 12 shows the results of FFT analysis of the current flowing through the DC-side capacitor 34 in this embodiment and the comparative example. When interleaved driving is performed, the current flowing through the first inductor 31 and the current flowing through the second inductor 32 flow so as to cancel each other's current ripple. This reduces the current ripple component that flows in and out of the DC-side capacitor 34 and fluctuates with the switching frequency of the first and second upper and lower arm switches S1H, S1L, S2H, and S2L. As a result, the rated value of the ripple current of the DC-side capacitor 34 can be reduced, which in turn reduces the capacitance of the DC-side capacitor 34 and makes the DC-side capacitor 34 more compact.

[0093] <Other embodiments> The above-described embodiments may be modified as follows.

[0094] As shown in FIG. 13, instead of the high-potential side path 30H, the low-potential side path 30L may be connected to the third path 43 via a series connection of a compensation capacitor 47 and a compensation switch 48.

[0095] During single-phase charging control, if bidirectional power conversion is not performed and only unidirectional power conversion from AC power to DC power is performed, upper and lower arm diodes D4H and D4L may be provided instead of the fourth upper and lower arm switches S4H and S4L, as shown in Fig. 14. In this case, the cathodes of the diodes D4H and D4L correspond to the high-potential side terminals, and the anodes correspond to the low-potential side terminals.

[0096] The first upper arm switch may be configured as a parallel connection of a plurality of N-channel MOSFETs. The same applies to the first lower arm switch and the second to fourth upper and lower arm switches.

[0097] The upper and lower arm switches are not limited to N-channel MOSFETs, but may be, for example, IGBTs with freewheeling diodes connected in reverse parallel. In this case, the collector of the IGBT corresponds to the high-potential terminal, and the emitter corresponds to the low-potential terminal.

[0098] Instead of the DC side capacitor 34 and the compensation capacitor 47, for example, a small-capacity rechargeable battery may be provided.

[0099] The power storage unit connected to the output of the DC-DC converter 24 is not limited to a storage battery, but may be, for example, a large-capacity electric double layer capacitor, or both a storage battery and an electric double layer capacitor.

[0100] The mobile body on which the power conversion device is mounted is not limited to a vehicle, but may be, for example, an aircraft or a ship.Furthermore, the power conversion device is not limited to a mobile body, but may be a stationary device.

[0101] The control unit and the method described herein may be implemented by a special-purpose computer configured by configuring a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the control unit and the method described herein may be implemented by a special-purpose computer configured by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the control unit and the method described herein may be implemented by one or more special-purpose computers configured by combining a processor and memory programmed to perform one or more functions with a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by a computer on a computer-readable non-transitory tangible storage medium.

[0102] The following describes characteristic configurations extracted from the above-described embodiments. [Configuration 1] a first AC terminal (Tac1), a second AC terminal (Tac2), a third AC terminal (Tac3) and a fourth AC terminal (Tac4); A high-potential side DC terminal (TdcH) and a low-potential side DC terminal (TdcL), Equipped with a power conversion device (10) configured so that a three-phase AC power supply (21) can be connected to the first AC terminal, the second AC terminal, and the third AC terminal, and a single-phase AC power supply (22) can be connected to the first AC terminal and the fourth AC terminal, a series connection of a first upper arm switch (S1H) and a first lower arm switch (S1L); a series connection of a second upper arm switch (S2H) and a second lower arm switch (S2L); a series connection of a third upper arm switch (S3H) and a third lower arm switch (S3L); a series connection of an upper arm rectifier unit (S4H, D4H) and a lower arm rectifier unit (S4L, D4L); a high potential side path (30H) electrically connecting the high potential side terminals of the first, second, and third upper arm switches, the high potential side terminal of the upper arm rectifier unit, and the high potential side DC terminal; a low potential side path (30L) electrically connecting the low potential side terminals of the first, second, and third lower arm switches, the low potential side terminal of the lower arm rectifier unit, and the low potential side DC terminal; a first inductor (31) that electrically connects a connection point between the first upper arm switch and the first lower arm switch and the first AC terminal; a second inductor (32) that electrically connects a connection point between the second upper arm switch and the second lower arm switch and the second AC terminal; a third inductor (33) that electrically connects a connection point between the third upper arm switch and the third lower arm switch and the third AC terminal; a connection path (44) that electrically connects a connection point between the upper arm rectifier and the lower arm rectifier and the fourth AC terminal; a DC side storage unit (34) electrically connecting the high potential side path and the low potential side path; a series connection of a compensation storage unit (47) and a compensation switch (48) that electrically connects the high potential side path or the low potential side path to the third AC terminal; a first single-phase charging switch (45) provided in the connection path; a second single-phase charging switch (46) that electrically connects the first AC terminal and the second AC terminal; a control unit (70); Equipped with When the control unit determines that the single-phase AC power supply is connected to the first AC terminal and the fourth AC terminal, with the compensation switch, the first single-phase charging switch, and the second single-phase charging switch turned on, the control unit controls the switching of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch to convert AC power input from the first AC terminal and the fourth AC terminal into DC power and output it from the high potential side DC terminal and the low potential side DC terminal, and controls the switching of the third upper arm switch and the third lower arm switch to reduce pulsation in the DC power output from the high potential side DC terminal and the low potential side DC terminal due to charging and discharging of the compensation storage unit. [Configuration 2] when it is determined that the three-phase AC power supply is connected to the first AC terminal, the second AC terminal, and the third AC terminal, the control unit performs switching control of the first upper arm switch, the first lower arm switch, the second upper arm switch, the second lower arm switch, the third upper arm switch, and the third lower arm switch in a state where the compensation switch, the first single-phase charging switch, and the second single-phase charging switch are turned off, so as to convert AC power input from the first AC terminal, the second AC terminal, and the third AC terminal into DC power and output it from the high potential side DC terminal and the low potential side DC terminal; a maximum value of DC power output from the high potential side DC terminal and the low potential side DC terminal when the three-phase AC power supply is connected to the first AC terminal, the second AC terminal, and the third AC terminal is defined as Pdcmax; The power conversion device described in configuration 1, wherein when the control unit determines that the single-phase AC power supply is connected to the first AC terminal and the fourth AC terminal, it performs switching control of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch so that the maximum value of the DC power output from the high potential side DC terminal and the low potential side DC terminal is greater than Pdcmax / 3 and less than or equal to Pdcmax×2 / 3. [Configuration 3] The control unit when it is determined that the three-phase AC power supply is connected to the first AC terminal, the second AC terminal, and the third AC terminal, in a state in which the compensation switch, the first single-phase charging switch, and the second single-phase charging switch are turned off, switching control of the first upper arm switch, the first lower arm switch, the second upper arm switch, the second lower arm switch, the third upper arm switch, and the third lower arm switch is performed so that DC power (P1) transmitted to the high potential side DC terminal and the low potential side DC terminal via the first inductor, DC power (P2) transmitted to the high potential side DC terminal and the low potential side DC terminal via the second inductor, and DC power (P3) transmitted to the high potential side DC terminal and the low potential side DC terminal via the third inductor are equal to each other; A power conversion device as described in configuration 2, wherein when it is determined that the single-phase AC power supply is connected to the first AC terminal and the fourth AC terminal, when the compensation switch, the first single-phase charging switch, and the second single-phase charging switch are turned on, switching control of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch is performed so that the DC power (P1) transmitted to the high potential side DC terminal and the low potential side DC terminal via the first inductor is equivalent to the DC power (P2) transmitted to the high potential side DC terminal and the low potential side DC terminal via the second inductor. [Configuration 4] 4. The power conversion device according to any one of configurations 1 to 3, wherein the control unit varies the voltage of the compensation storage unit in a half cycle of the output voltage of the single-phase AC power supply in order to reduce pulsation in the DC power output from the high potential side DC terminal and the low potential side DC terminal due to charging and discharging of the compensation storage unit, and performs switching control of the third upper arm switch and the third lower arm switch so that a peak value of the voltage of the compensation storage unit in one cycle of the output voltage of the single-phase AC power supply is smaller than a value obtained by multiplying π / 2 by a time average value of the voltage of the compensation storage unit in one cycle of the output voltage. [Configuration 5] 5. The power conversion device according to any one of configurations 1 to 4, wherein the upper arm rectifier and the lower arm rectifier allow current to flow from their own low potential side terminals to their own high potential side terminals. [Configuration 6] the upper arm rectifier is a fourth upper arm switch (S4H) having an anti-parallel connected diode; the lower arm rectifier is a fourth lower arm switch (S4L) having an anti-parallel connected diode; The control unit turning on the fourth lower arm switch and turning off the fourth upper arm switch during a period in which it is determined that a current is flowing in a direction from the fourth AC terminal to the first AC terminal via the single-phase AC power supply; A power conversion device as described in configuration 5, wherein the fourth upper arm switch is turned on and the fourth lower arm switch is turned off during a period in which it is determined that current is flowing in a direction from the first AC terminal to the fourth AC terminal via the single-phase AC power supply. [Configuration 7] 7. The power conversion device according to configuration 6, wherein the fourth upper arm switch and the fourth lower arm switch are switches having longer turn-on times and turn-off times than the first to third upper and lower arm switches. [Configuration 8] A power conversion device described in any one of configurations 1 to 7, wherein the control unit alternately turns on the first upper arm switch and the first lower arm switch, alternately turns on the second upper arm switch and the second lower arm switch, and staggers the timing of switching the switching state of the first upper arm switch and the timing of switching the switching state of the second upper arm switch to convert AC power input from the first AC terminal and the fourth AC terminal into DC power and output it from the high potential side DC terminal and the low potential side DC terminal. [Configuration 9] a first AC terminal (Tac1), a second AC terminal (Tac2), a third AC terminal (Tac3) and a fourth AC terminal (Tac4); A high potential side DC terminal (TdcH) and a low potential side DC terminal (TdcL), a computer (71); A power conversion device (10) comprising: a power conversion device configured so that a three-phase AC power supply (21) can be connected to the first AC terminal, the second AC terminal, and the third AC terminal, and a single-phase AC power supply (22) can be connected to the first AC terminal and the fourth AC terminal, The power conversion device is a series connection of a first upper arm switch (S1H) and a first lower arm switch (S1L); A series connection of a second upper arm switch (S2H) and a second lower arm switch (S2L); a series connection of a third upper arm switch (S3H) and a third lower arm switch (S3L); a series connection of an upper arm rectifier unit (S4H, D4H) and a lower arm rectifier unit (S4L, D4L); a high potential side path (30H) electrically connecting the high potential side terminals of the first, second, and third upper arm switches, the high potential side terminal of the upper arm rectifier unit, and the high potential side DC terminal; a low potential side path (30L) electrically connecting the low potential side terminals of the first, second, and third lower arm switches, the low potential side terminal of the lower arm rectifier unit, and the low potential side DC terminal; a first inductor (31) that electrically connects a connection point between the first upper arm switch and the first lower arm switch and the first AC terminal; a second inductor (32) that electrically connects a connection point between the second upper arm switch and the second lower arm switch and the second AC terminal; a third inductor (33) that electrically connects a connection point between the third upper arm switch and the third lower arm switch and the third AC terminal; a connection path (44) that electrically connects a connection point between the upper arm rectifier and the lower arm rectifier and the fourth AC terminal; a DC side storage unit (34) electrically connecting the high potential side path and the low potential side path; a series connection of a compensation storage unit (47) and a compensation switch (48) that electrically connects the high potential side path or the low potential side path to the third AC terminal; a first single-phase charging switch (45) provided in the connection path; a second single-phase charging switch (46) that electrically connects the first AC terminal and the second AC terminal; Equipped with The computer, a process of determining whether the single-phase AC power supply is connected to the first AC terminal and the fourth AC terminal; a process of performing switching control of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch in a state where the compensation switch, the first single-phase charging switch, and the second single-phase charging switch are turned on, when it is determined that the single-phase AC power supply is connected, to convert AC power input from the first AC terminal and the fourth AC terminal into DC power and output it from the high potential side DC terminal and the low potential side DC terminal, and performing switching control of the third upper arm switch and the third lower arm switch in order to reduce pulsation of the DC power output from the high potential side DC terminal and the low potential side DC terminal due to charging and discharging of the compensation storage unit; A program that executes. [Explanation of symbols]

[0103] 10...power conversion device, 21...three-phase AC power supply, 22...single-phase AC power supply, 31-33...first to third inductors, 44...connection path, 45...first single-phase charging switch, 46...second single-phase charging switch, 47...compensation capacitor, 48...compensation switch, 70...control device, S1H, S2H, S3H, S4H...first to fourth upper arm switches, S1L, S2L, S3L, S4L...first to fourth lower arm switches.

Claims

1. a first AC terminal (Tac1), a second AC terminal (Tac2), a third AC terminal (Tac3), and a fourth AC terminal (Tac4); a high potential side DC terminal (TdcH) and a low potential side DC terminal (TdcL); Equipped with A power conversion device (10) configured so that a three-phase AC power supply (21) can be connected to the first AC terminal, the second AC terminal, and the third AC terminal, and a single-phase AC power supply (22) can be connected to the first AC terminal and the fourth AC terminal, a series connection of a first upper arm switch (S1H) and a first lower arm switch (S1L); a series connection of a second upper arm switch (S2H) and a second lower arm switch (S2L); a series connection of a third upper arm switch (S3H) and a third lower arm switch (S3L); a series connection of an upper arm rectifier unit (S4H, D4H) and a lower arm rectifier unit (S4L, D4L); a high-potential-side path (30H) electrically connecting the high-potential-side terminals of the first, second, and third upper arm switches, the high-potential-side terminal of the upper arm rectifier unit, and the high-potential-side DC terminal; a low potential side path (30L) electrically connecting the low potential side terminals of the first, second, and third lower arm switches, the low potential side terminal of the lower arm rectifier unit, and the low potential side DC terminal; a first inductor (31) electrically connecting a connection point between the first upper arm switch and the first lower arm switch and the first AC terminal; a second inductor (32) electrically connecting a connection point between the second upper arm switch and the second lower arm switch and the second AC terminal; a third inductor (33) electrically connecting a connection point between the third upper arm switch and the third lower arm switch and the third AC terminal; a connection path (44) electrically connecting a connection point between the upper arm rectifier and the lower arm rectifier and the fourth AC terminal; a DC side storage unit (34) electrically connecting the high potential side path and the low potential side path; a series connection of a compensation storage unit (47) and a compensation switch (48) that electrically connects the high potential side path or the low potential side path to the third AC terminal; a first single-phase charging switch (45) provided in the connection path; a second single-phase charging switch (46) electrically connecting the first AC terminal and the second AC terminal; A control unit (70); Equipped with When the control unit determines that the single-phase AC power supply is connected to the first AC terminal and the fourth AC terminal, with the compensation switch, the first single-phase charging switch, and the second single-phase charging switch turned on, the control unit controls the switching of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch to convert AC power input from the first AC terminal and the fourth AC terminal into DC power and output it from the high potential side DC terminal and the low potential side DC terminal, and controls the switching of the third upper arm switch and the third lower arm switch to reduce pulsation in the DC power output from the high potential side DC terminal and the low potential side DC terminal due to charging and discharging of the compensation storage unit.

2. when it is determined that the three-phase AC power supply is connected to the first AC terminal, the second AC terminal, and the third AC terminal, the control unit performs switching control of the first upper arm switch, the first lower arm switch, the second upper arm switch, the second lower arm switch, the third upper arm switch, and the third lower arm switch in a state in which the compensation switch, the first single-phase charging switch, and the second single-phase charging switch are turned off, so as to convert AC power input from the first AC terminal, the second AC terminal, and the third AC terminal into DC power and output it from the high potential side DC terminal and the low potential side DC terminal; a maximum value of DC power output from the high potential side DC terminal and the low potential side DC terminal when the three-phase AC power supply is connected to the first AC terminal, the second AC terminal, and the third AC terminal is defined as Pdcmax; 2. The power conversion device according to claim 1, wherein, when it is determined that the single-phase AC power supply is connected to the first AC terminal and the fourth AC terminal, the control unit performs switching control of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch so that a maximum value of DC power output from the high potential side DC terminal and the low potential side DC terminal is greater than Pdcmax / 3 and less than or equal to Pdcmax×2 / 3.

3. The control unit when it is determined that the three-phase AC power supply is connected to the first AC terminal, the second AC terminal, and the third AC terminal, in a state in which the compensation switch, the first single-phase charging switch, and the second single-phase charging switch are turned off, switching control of the first upper arm switch, the first lower arm switch, the second upper arm switch, the second lower arm switch, the third upper arm switch, and the third lower arm switch is performed so that DC power (P1) transmitted to the high potential side DC terminal and the low potential side DC terminal via the first inductor, DC power (P2) transmitted to the high potential side DC terminal and the low potential side DC terminal via the second inductor, and DC power (P3) transmitted to the high potential side DC terminal and the low potential side DC terminal via the third inductor are equal to each other; 3. The power conversion device according to claim 2, wherein, when it is determined that the single-phase AC power supply is connected to the first AC terminal and the fourth AC terminal, in a state in which the compensation switch, the first single-phase charging switch, and the second single-phase charging switch are turned on, switching control of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch is performed so that DC power (P1) transmitted to the high potential side DC terminal and the low potential side DC terminal via the first inductor is equivalent to DC power (P2) transmitted to the high potential side DC terminal and the low potential side DC terminal via the second inductor.

4. 4. The power conversion device according to claim 1, wherein the control unit varies the voltage of the compensation power storage unit in a half cycle of the output voltage of the single-phase AC power supply, in order to reduce pulsation in the DC power output from the high potential side DC terminal and the low potential side DC terminal due to charging and discharging of the compensation power storage unit, and performs switching control of the third upper arm switch and the third lower arm switch so that a peak value of the voltage of the compensation power storage unit in one cycle of the output voltage of the single-phase AC power supply is smaller than a value obtained by multiplying π / 2 by a time average value of the voltage of the compensation power storage unit in one cycle of the output voltage.

5. The power conversion device according to any one of claims 1 to 3, wherein the upper arm rectifier and the lower arm rectifier allow current to flow from their own low potential side terminals to their own high potential side terminals.

6. the upper arm rectifier is a fourth upper arm switch (S4H) having an anti-parallel connected diode; The lower arm rectifier is a fourth lower arm switch (S4L) having an anti-parallel connected diode, The control unit turning on the fourth lower arm switch and turning off the fourth upper arm switch during a period in which it is determined that a current is flowing in a direction from the fourth AC terminal to the first AC terminal via the single-phase AC power supply; 6. The power conversion device according to claim 5, wherein the fourth upper arm switch is turned on and the fourth lower arm switch is turned off during a period in which it is determined that a current is flowing in a direction from the first AC terminal to the fourth AC terminal via the single-phase AC power supply.

7. 7. The power conversion device according to claim 6, wherein the fourth upper arm switch and the fourth lower arm switch are switches having longer turn-on times and turn-off times than the first to third upper and lower arm switches.

8. The control unit alternately turns on the first upper arm switch and the first lower arm switch, alternately turns on the second upper arm switch and the second lower arm switch, and staggers the timing of switching the switching state of the first upper arm switch and the timing of switching the switching state of the second upper arm switch, in order to convert AC power input from the first AC terminal and the fourth AC terminal into DC power and output it from the high potential side DC terminal and the low potential side DC terminal.A power conversion device as described in any one of claims 1 to 3.

9. a first AC terminal (Tac1), a second AC terminal (Tac2), a third AC terminal (Tac3), and a fourth AC terminal (Tac4); a high potential side DC terminal (TdcH) and a low potential side DC terminal (TdcL); A computer (71); A power conversion device (10) comprising: A program applied to a power conversion device configured so that a three-phase AC power supply (21) can be connected to the first AC terminal, the second AC terminal, and the third AC terminal, and so that a single-phase AC power supply (22) can be connected to the first AC terminal and the fourth AC terminal, The power conversion device is a series connection of a first upper arm switch (S1H) and a first lower arm switch (S1L); a series connection of a second upper arm switch (S2H) and a second lower arm switch (S2L); a series connection of a third upper arm switch (S3H) and a third lower arm switch (S3L); a series connection of an upper arm rectifier unit (S4H, D4H) and a lower arm rectifier unit (S4L, D4L); a high-potential-side path (30H) electrically connecting the high-potential-side terminals of the first, second, and third upper arm switches, the high-potential-side terminal of the upper arm rectifier unit, and the high-potential-side DC terminal; a low potential side path (30L) electrically connecting the low potential side terminals of the first, second, and third lower arm switches, the low potential side terminal of the lower arm rectifier unit, and the low potential side DC terminal; a first inductor (31) electrically connecting a connection point between the first upper arm switch and the first lower arm switch and the first AC terminal; a second inductor (32) electrically connecting a connection point between the second upper arm switch and the second lower arm switch and the second AC terminal; a third inductor (33) electrically connecting a connection point between the third upper arm switch and the third lower arm switch and the third AC terminal; a connection path (44) electrically connecting a connection point between the upper arm rectifier and the lower arm rectifier and the fourth AC terminal; a DC side storage unit (34) electrically connecting the high potential side path and the low potential side path; a series connection of a compensation storage unit (47) and a compensation switch (48) that electrically connects the high potential side path or the low potential side path to the third AC terminal; a first single-phase charging switch (45) provided in the connection path; a second single-phase charging switch (46) electrically connecting the first AC terminal and the second AC terminal; Equipped with The computer, a process of determining whether the single-phase AC power supply is connected to the first AC terminal and the fourth AC terminal; a process of performing switching control of the first upper arm switch, the first lower arm switch, the second upper arm switch, and the second lower arm switch in a state where the compensation switch, the first single-phase charging switch, and the second single-phase charging switch are turned on, when it is determined that the single-phase AC power supply is connected, to convert AC power input from the first AC terminal and the fourth AC terminal into DC power and output it from the high potential side DC terminal and the low potential side DC terminal, and performing switching control of the third upper arm switch and the third lower arm switch in order to reduce pulsation in the DC power output from the high potential side DC terminal and the low potential side DC terminal due to charging and discharging of the compensation storage unit; A program that executes.

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