Power conversion device and program

JP2024065970A5Active Publication Date: 2025-01-24SOKEN CO LTD +1
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Patent Information

Application Number
JP2022175109
Authority / Receiving Office
JP · JP
Patent Type
Applications
Current Assignee / Owner
Filing Date
2022-10-31
Publication Date
2025-01-24
Estimated Expiration
2042-10-31

AI Technical Summary

Technical Problem

Power converters often require common mode filters to meet EMC standards, but existing designs do not efficiently manage current distribution, leading to increased coil ratings and size.

Method used

A power conversion device with a common mode filter that includes coils connected in parallel to distribute current more evenly, reducing the rated current and size of coils, particularly in paths with higher current flow.

Benefits of technology

The solution effectively reduces coil ratings and sizes, enhancing efficiency and compactness of the power conversion device while meeting EMC standards.

✦ Generated by Eureka AI based on patent content.

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Abstract

To provide a new power conversion device having a common mode filter, and a program.SOLUTION: A power conversion device 10 comprises AC terminals Tac1 to Tac3 of a plurality of phases, and DC terminals TdcH and TdcL, and converts AC power input from the AC terminals Tac1 to Tac3 into a DC power to output it from the DC terminals TdcH and TdcL. The power conversion device 10 comprises: first to third paths 41 to 43; first to third inductors 31 to 33 that are provided to each of the first to third paths 41 to 43; and a common mode filter 35. The common mode filter 35 comprises: first to fourth coils 36A to 36D. Each of the first to third coils 36A to 36C is provided to the first to third paths 41 to 43. In the third coil 36C, a fourth coil 36D is parallely connected.SELECTED DRAWING: Figure 1
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Description

[Technical field]

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

[0002] Conventionally, a power conversion device including a multi-phase AC terminal, a DC terminal, and an AC-DC conversion circuit is known. The AC-DC conversion circuit has at least one of a function of converting AC power inputted from the AC terminal into DC power and outputting it from the DC terminal, and a function of converting DC power inputted from the DC terminal into AC power and outputting it from the AC terminal. As such a power conversion device, for example, as described in Patent Document 1, a power conversion device compatible with both a three-phase AC power source and a single-phase AC power source is known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2022-503713 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to satisfy the requirements of EMC standards for power conversion devices, the power conversion device may be provided with a common mode filter.

[0005] A primary object of the present invention is to provide a new power conversion device including a common mode filter and a program therefor. [Means for solving the problem]

[0006] The first aspect of the present invention is a multiple-phase AC terminal; A DC terminal, an AC-DC conversion circuit having at least one of a function of converting AC power inputted from the AC terminal into DC power and outputting the DC power from the DC terminal, and a function of converting DC power inputted from the DC terminal into AC power and outputting the AC power from the AC terminal; In a power conversion device comprising: an electrical path provided for each phase, connecting the AC / DC conversion circuit and the AC terminal; A common mode filter; Equipped with The common mode filter includes: A coil provided in the electrical path of each phase; A specific coil connected in parallel to at least one of the coils; a core around which each of the coils and the specific coil are wound; has.

[0007] According to the first aspect of the present invention, when a current flows through each electrical path, the current flowing through the specific coil can be distributed between the coil connected in parallel to the specific coil and the specific coil. By connecting the specific coil in parallel to a target coil having a relatively larger current flowing through it than the other coils, the current flowing through the target coil can be reduced. As a result, the rated current of the target coil can be reduced. In this way, according to the first aspect of the present invention, a new power conversion device equipped with a common mode filter can be provided.

[0008] The first invention can be embodied as, for example, the following second invention. In the second invention, the AC terminals include a first AC terminal, a second AC terminal, and a third AC terminal, The DC terminals include a high potential side DC terminal and a low potential side DC terminal, a three-phase AC power supply is connectable to the first AC terminal, the second AC terminal, and the third AC terminal, and a single-phase AC power supply is connectable to the first AC terminal and the third AC terminal, The AC / DC conversion circuit includes: 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 third upper arm switch and a third lower arm switch connected in series; having The electrical path includes: a first path electrically connecting a connection point between the first upper arm switch and the first lower arm switch and the first AC terminal; a second path electrically connecting a connection point between the second upper arm switch and the second lower arm switch and the second AC terminal; a third path electrically connecting a connection point between the third upper arm switch and the third lower arm switch and the third AC terminal; is provided, a first inductor provided in the first path; a second inductor provided in the second path; a third inductor provided in the third path; a single-phase charging switch that electrically connects the first AC terminal and the second AC terminal; The control unit; Equipped with The high potential side terminals of the first, second and third upper arm switches are electrically connected to the high potential side DC terminal, The low potential side terminals of the first, second and third lower arm switches are electrically connected to the low potential side DC terminal, when it is determined that the single-phase AC power supply is connected to the first 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, and the second lower arm switch in a state in which the single-phase charging switch is turned on, so as to perform power conversion between the first AC terminal and the third AC terminal and the high potential side DC terminal and the low potential side DC terminal; The coil constituting the common mode filter is a first coil provided in the first path closer to the first AC terminal than the first inductor; a second coil provided in the second path closer to the second AC terminal than the second inductor; a third coil provided in the third path closer to the third AC terminal than the third inductor; is provided, The specific coil is connected in parallel to the third coil.

[0009] In a second aspect of the present invention, 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 perform power conversion between the first and third AC terminals and the high potential side DC terminal and the low potential side DC terminal when the single-phase charging switch is on. Because the single-phase charging switch is on, all of the first to third paths can be used as power transmission paths during power conversion using a single-phase AC power source. This makes it possible to increase the transmitted power during power conversion.

[0010] In this case, the current flowing through the third path is larger than the current flowing through the first and second paths. Therefore, in the second invention, the specific coil constituting the common mode filter is connected in parallel to the third coil provided in the third path. This makes it possible to reduce the current flowing through the third coil, and therefore the rated current of the third coil. [Brief description of the drawings]

[0011] [Figure 1] 1 is an overall configuration diagram of an on-board charger according to a first embodiment. [Diagram 2] FIG. 2 is a plan view of a common mode filter. [Diagram 3] FIG. 1 shows an on-board charger connected to a three-phase AC power supply. [Figure 4] FIG. 2 is a diagram showing an on-board charger connected to a single-phase AC power supply. [Diagram 5] 4 is a flowchart showing a procedure for controlling charging of a storage battery. [Figure 6] Block diagram of three-phase charging control processing. [Figure 7] FIG. 1 is a block diagram of a single-phase charging control process. [Figure 8] FIG. 13 is a diagram showing an on-board charger connected to a single-phase AC power supply according to a comparative example. [Figure 9] FIG. 11 is an overall configuration diagram of an on-board charger according to a second embodiment. [Figure 10] 4 is a flowchart showing a procedure for controlling charging of a storage battery. [Figure 11] FIG. 1 shows an on-board charger connected to a three-phase AC power supply. [Figure 12] FIG. 2 is a diagram showing an on-board charger connected to a single-phase AC power supply. [Figure 13] FIG. 11 is an overall configuration diagram of an on-board charger according to a third embodiment. [Figure 14] 4 is a flowchart showing a procedure for controlling charging of a storage battery. [Figure 15] FIG. 1 shows an on-board charger connected to a three-phase AC power supply. [Figure 16] FIG. 2 is a diagram showing an on-board charger connected to a single-phase AC power supply. [Figure 17] FIG. 13 is a diagram showing a power conversion device according to another embodiment. [Figure 18] FIG. 13 is a diagram showing a power conversion device according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Several embodiments will be described with reference to the drawings. In several embodiments, functionally and / or structurally corresponding and / or associated parts may be given the same reference numerals or reference numerals with different digits of 100 or more. For corresponding and / or associated parts, the description of other embodiments may be referred to.

[0013] First Embodiment Hereinafter, a first embodiment of a power conversion device according to the present invention will be described 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.

[0014] 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 outside the vehicle into DC power and outputting the DC power 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 from the DC terminal into AC power and outputting the AC power 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.

[0015] As shown in Fig. 1, the power conversion device 10 includes a first AC terminal Tac1, a second AC terminal Tac2, and a third AC terminal Tac3 as AC terminals. The first to third AC terminals Tac1 to Tac3 are connectable to an external three-phase AC power source 21 as shown in Fig. 3. Of the first to third AC terminals Tac1 to Tac3, the first and third AC terminals Tac1 and Tac3 are connectable to an external single-phase AC power source 22 as shown in Fig. 4.

[0016] The power conversion device 10 includes 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 DCDC converter 24 constituting an on-board charger. The output section of the DCDC converter 24 is connected to a chargeable and dischargeable storage battery 20 mounted on a vehicle. The DCDC converter 24 transforms a DC voltage inputted 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 DCDC converter 24 also transforms a DC voltage inputted 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 DCDC converter 24 is, for example, an insulated DCDC converter in which an input section and an output section are electrically insulated, and includes a transformer that connects the input section and the output section.

[0017] The power conversion device 10 includes, as upper and lower arm switches for three 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, and a series connection of a third upper arm switch S3H and a third lower arm switch S3L. In this embodiment, each of the upper and lower arm switches S1H to S3L is an N-channel MOSFET having a body diode. Therefore, in each of the upper and lower arm switches S1H to S3L, 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.

[0018] The power conversion device 10 includes a high-potential side path 30H that is an electrical path connecting the high-potential side terminals of the first, second, and third upper arm switches S1H, S2H, and S3H to the high-potential side DC terminal TdcH, and a low-potential side path 30L that is an electrical path connecting the low-potential side terminals of the first, second, and third lower arm switches S1L, S2L, and S3L to the 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.

[0019] 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.

[0020] 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 that connects 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 to the first AC terminal Tac1. The second path 42 is an electrical path that connects 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 to the second AC terminal Tac2. The third path 43 is an electrical path that connects 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 to the third AC terminal Tac3.

[0021] 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. In addition, the inductors 31 to 33 have the same rated current (specifically, temperature rise rated current).

[0022] The power conversion device 10 includes a common mode filter 35. The common mode filter 35 includes a first coil 36A, a second coil 36B, a third coil 36C, and a fourth coil 36D as a "specific coil". The first to third coils 36A to 36C are provided on the first to third paths 41 to 43 closer to the first to third AC terminals Tac1 to Tac3 than the first to third inductors 31 to 33. The fourth coil 36D is connected in parallel to the third coil 36C. The input side of the power conversion device 10 is three-phase, while the common mode filter 35 includes coils for four phases in order to reduce the rated current of the coils and to miniaturize the common mode filter 35. This will be described in detail later.

[0023] As shown in FIG. 2, the common mode filter 35 includes a common core 37 around which the coils 36A to 36D are wound. The core 37 is annular (specifically, circular) and made of, for example, ferrite. The coils 36A to 36D are arranged at equal intervals in the circumferential direction of the core 37. The coils 36A to 36D of this embodiment have the same rated current (specifically, temperature rise rated current). For example, by making the number of turns and wire diameter the same for the coils 36A to 36D, the rated current for the coils 36A to 36D can be set to the same value.

[0024] The power conversion device 10 includes a single-phase charging switch 46. The single-phase charging switch 46 connects a portion of the first path 41 closer to the first AC terminal Tac1 than the first coil 36A and a portion of the second path 42 closer to the second AC terminal Tac2 than the second coil 36B. The single-phase charging switch 46 allows bidirectional current flow when it is turned on, and blocks bidirectional current flow when it is turned off. Note that the single-phase charging switch 46 may connect the first AC terminal Tac1 and the second AC terminal Tac2, for example.

[0025] The power conversion device 10 includes a DC side voltage sensor 50 and an AC side voltage sensor 51. The DC side voltage sensor 50 detects the terminal voltage of the DC side capacitor 34, and the AC side voltage sensor 51 detects the voltage difference between the first AC terminal Tac1 and the ground of the power conversion device 10.

[0026] 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 detection values ​​of the sensors 50, 51, 61 to 63 are input to a control device 70 serving as a control unit included in the power conversion device 10.

[0027] The control device 70 is mainly composed of a microcomputer 71, and the microcomputer 71 includes a CPU. The functions provided by the microcomputer 71 can be provided by software recorded in a substantial memory device and a computer that executes the software, by software alone, by hardware alone, or by a combination of these. For example, when the microcomputer 71 is provided by an electronic circuit that is hardware, it can be provided by a digital circuit including a large number of logic circuits, or by an analog circuit. For example, the microcomputer 71 executes a program stored in a non-transitory tangible storage medium as a storage unit provided in the microcomputer 71. The program includes, for example, programs for processing shown in Figs. 5, 10, 14, etc., which will be described later. By executing the program, a method corresponding to the program is executed. 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, OTA (Over The Air), etc.

[0028] 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.

[0029] In step S10, it is determined whether or not a command for three-phase charging control has been issued. In this embodiment, when it is determined that a three-phase AC power supply 21 is connected to the first to third AC terminals Tac1 to Tac3 as shown in Fig. 3, it is determined that a command for three-phase charging control has been issued. In the three-phase AC power supply 21, the amplitudes and frequencies of the three-phase output voltages V1, V2, and V3 are the same, and the phases of the output voltages V1, V2, and V3 and the output current are shifted by 120° for each phase.

[0030] If the determination in step S10 is affirmative, three-phase charging control is performed in steps S11 and S12. More specifically, in step S11, the single-phase charging switch 46 is turned off.

[0031] 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 in order to convert the AC power inputted from the first AC terminal Tac1, the second AC terminal Tac2 and the third AC terminal Tac3 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 with a dead time therebetween. In each phase, one switching period of the upper and lower arm switches is the same.

[0032] 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. 4, if it is determined that the single-phase AC power supply 22 is connected to the first AC terminal Tac1 and the third AC terminal Tac3, it is determined that a command for single-phase charging control has been issued. In this embodiment, the amplitude Vac 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.

[0033] If the determination in step S13 is affirmative, single-phase charging control is performed in steps S14 and S 15. More specifically, in step S14, the single-phase charging switch 46 is turned on.

[0034] 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 inputted from the first AC terminal Tac1 and the third AC terminal Tac3 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 switch and the lower arm switch are alternately turned on in synchronization with each other with a dead time therebetween. In each phase, one switching period of the upper and lower arm switches is the same, which is the same as one switching period during three-phase charging control.

[0035] In step S15, in a first period in which an AC current flows from the third AC terminal Tac3 to the first AC terminal Tac1 via the single-phase AC power supply 22, the third lower arm switch S3L is turned on and the third upper arm switch S3H is turned off. On the other hand, in a second period in which a current flows from the first AC terminal Tac1 to the third AC terminal Tac3 via the single-phase AC power supply 22, the third upper arm switch S3H is turned on and the third lower arm switch S3L is turned off. Whether the current timing is included in the first period or the second period may be determined based on, for example, a detection value of the first current sensor 61.

[0036] Incidentally, during single-phase charging control, when DC power inputted from each DC terminal TdcH, TdcL is converted into AC power by switching control of the first upper and lower arm switches S1H, S1L and the second upper and lower arm switches S2H, S2L and outputted from the first and third AC terminals Tac1, Tac3, in step S15, in a first period in which a current flows from the third AC terminal Tac3 to the first AC terminal Tac1 via the single-phase AC power source 22, the third upper arm switch S3H is turned on and the third lower arm switch S3L is turned off. On the other hand, in a second period in which a current flows from the first AC terminal Tac1 to the third AC terminal Tac3 via the single-phase AC power source 22, the third lower arm switch S3L is turned on and the third upper arm switch S3H is turned off.

[0037] Next, the three-phase charging control will be described with reference to Fig. 6. Fig. 6 is a block diagram of the three-phase charging control executed by the control device 70.

[0038] The 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, DC voltage detection value Vdcr) to a target DC voltage Vdcref (e.g., 800V). In detail, 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-S4L and the DC-DC converter 24, for example.

[0039] 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.

[0040] The electrical angle calculation unit 83 calculates the electrical angle θe based on the voltage detected by the AC side voltage sensor 51 (hereinafter, AC voltage detection value V1r). In this embodiment, the electrical angle θe at the zero cross timing (specifically, for example, zero up cross timing) of the AC voltage detection value V1r is set to 0°, and the electrical angle θe at the next zero up cross timing is set to 360°. As a result, one cycle of the AC voltage detection value V1r corresponds to one electrical angle cycle (0° to 360°). In this embodiment, the AC voltage detection value V1r is set to positive when the voltage of the first AC terminal Tac1 is higher than the voltage of the ground of the power conversion device 10. The ground is connected to the neutral point of the three-phase AC power source 21 or the single-phase AC power source 22.

[0041] 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-axis 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 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.

[0042] 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 .

[0043] 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 0. The feedback control in the d-axis feedback control unit 87 is, for example, proportional-integral control.

[0044] 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 is set to 0 in this embodiment 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 current detection values ​​i1r, i2r, and i3r 0. 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 0. The feedback control in the q-axis feedback control unit 89 is, for example, proportional-integral control.

[0045] 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. The sinusoidal signals are signals that become 0 every 180° of electrical angle.

[0046] The PWM generating unit 91 generates a first upper and lower arm drive signal to be supplied to the gates of the first upper and lower arm switches S1H and S1L, a second upper and lower arm drive signal to be supplied to the gates of the second upper and lower arm switches S2H and S2L, and a third upper and lower arm drive signal 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 the 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°). In one electrical angle cycle, the switching patterns of the first upper and lower arm switches S1H and S1L, the switching patterns of the second upper and lower arm switches S2H and S2L, and the switching patterns of the third upper and lower arm switches S3H and S3L are shifted in phase by 120° each.

[0047] 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. The first, second and third DC powers P1, P2 and P3 are individual DC powers output from the three-phase AC power supply 21 through the first, second and third inductors 31, 32 and 33 at the DC terminals TdcH and TdcL. This makes the effective values ​​of the currents flowing through the first, second and third inductors 31, 32 and 33 the same value (for example, 16 Arms).

[0048] 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.

[0049] 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.

[0050] In the control device 70, the filter unit 112 performs low-pass filtering on the DC voltage detection value Vdcr. This removes harmonic components of the output voltage of the single-phase AC power supply 22, which are included in the DC voltage detection value Vdcr. The harmonic components are, for example, components of the secondary frequency (for example, 100 Hz or 120 Hz) of the output voltage.

[0051] 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 controlling the voltage deviation ΔV to 0. The feedback control in the voltage feedback control unit 103 is, for example, proportional-integral control.

[0052] 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.

[0053] The current control unit 105 includes a target current calculation unit 106, a current deviation calculation unit 107, and a current feedback control unit .

[0054] The target current calculation unit 106 calculates the target current Iacref by multiplying the target current amplitude Iampref by a sine wave signal "sin×θe." The target current Iacref fluctuates with the same period as the AC voltage detection value V1r.

[0055] 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 in the current adder 110.

[0056] The current feedback control unit 108 calculates first and second target voltages Vleg1ref, Vleg2ref as manipulated variables for feedback controlling the current deviation ΔI to 0. 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 first and second target voltages Vleg1ref, Vleg2ref are calculated in the current feedback control unit 108 so that the first DC power P1 and the second DC power P2 are equal.

[0057] The PWM generating unit 111 generates a first upper and lower arm drive signal to be supplied to the gates of the first upper and lower arm switches S1H and S1L and a second upper and lower arm drive signal 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 the 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° in one electrical angle period. That is, the on-switching timing and the off-switching timing of the first upper arm switch S1H and the second upper arm switch S2H are synchronized, and the on-switching timing and the off-switching timing of the first lower arm switch S1L and the second lower arm switch S2L are synchronized.

[0058] In this embodiment, during single-phase charging control, the first and second target voltages Vleg1ref, Vleg2ref are calculated in the current feedback control unit 108 so that the first DC power P1 and the second DC power P2 are equal. As described above, the first and second DC powers P1, P2 are individual DC powers output from the three-phase AC power supply 21 via the first and second inductors 31, 32 and the DC terminals TdcH, TdcL.

[0059] Since the third coil 36C and the fourth coil 36D are connected in parallel, during single-phase charging control, the current flowing through the third path 43 is distributed to the third and fourth coils 36C and 36D, and is equally distributed in this embodiment. Therefore, the effective values ​​of the currents flowing through the first to fourth coils 36A to 36D can be set to the same value (e.g., 16 Arms), and the rated currents (specifically, temperature rise rated currents) of the first to fourth coils 36A to 36D can be set to the same value.

[0060] A configuration according to a comparative example is shown in Fig. 8. In the comparative example, the common mode filter 35 does not include the fourth coil 36D.

[0061] During single-phase charging control in the comparative example, the effective value of the current flowing through the third coil 36C is greater than the effective value of the current flowing through the first and second coils 36A and 36B. Specifically, the effective value of the current flowing through the third coil 36C is twice the effective value of the current flowing through the first and second coils 36A and 36B (e.g., 32 Arms). In general, the rated current of each coil constituting a common mode filter is set to the same value as the rated current of the coil having the largest effective value of the current flowing through each coil. For this reason, it is necessary to match the rated current of the first and second coils 36A and 36B to the rated current of the third coil 36C. When the rated current increases, the coil becomes larger, so in the comparative example, the first and second coils 36A and 36B become larger.

[0062] In contrast, in this embodiment, the rated current of the third and fourth coils 36C and 36D can be reduced to the rated current of the first and second coils 36A and 36B. As a result, the third and fourth coils 36C and 36D can be made smaller, and therefore the common mode filter 35 can be made smaller.

[0063] <Modification of the first embodiment> The number of specific coils connected in parallel to the third coil 36C is not limited to one, and may be multiple.

[0064] <Second embodiment> The second embodiment will be described below with reference to the drawings, focusing on the differences from the first embodiment.

[0065] In this embodiment, as shown in FIG. 9, the power conversion device 10 includes a series connection of a fourth upper arm switch S4H, which is an "upper arm rectifier," and a fourth lower arm switch S4L, which is a "lower arm rectifier," a second single-phase charging switch 47, and a third single-phase charging switch 487. In this embodiment, the fourth upper and lower arm switches S4H and S4L are N-channel MOSFETs having body diodes. The second and third single-phase charging switches 47 and 48 allow bidirectional current flow when they are turned on, and prevent bidirectional current flow when they are turned off. In this embodiment, the single-phase charging switch 46 is referred to as a first single-phase charging switch 46.

[0066] The second single-phase charging switch 47 and the third single-phase charging switch 48 are provided to reduce the effective value of the current flowing through the third inductor 33 during single-phase charging control and to reduce the rated current of the third inductor 33. The second single-phase charging switch 47 connects the connection point of the fourth upper and lower arm switches S4H, S4L to a portion of the third path 43 between the third inductor 33 and the third coil 36C. The third single-phase charging switch 48 connects a portion of the third path 43 closer to the third AC terminal Tac3 than the third coil 36C to the fourth AC terminal Tac4. The third single-phase charging switch 48 may connect the third AC terminal Tac3 and the fourth AC terminal Tac4.

[0067] The charging control executed by the control device 70 will be described with reference to FIG.

[0068] In step S20, it is determined whether or not a command for three-phase charging control has been issued. In this embodiment, as shown in Fig. 11, 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. Note that, although the neutral point of the three-phase AC power supply 21 is connected to the fourth AC terminal Tac4 in Fig. 11, the neutral point does not have to be connected to the fourth AC terminal Tac4.

[0069] If the determination in step S20 is affirmative, three-phase charging control is performed in steps S21 and S22. More specifically, in step S21, the first to third single-phase charging switches 46-48 and the fourth upper and lower arm switches S4H, S4L are turned off (see FIG. 11).

[0070] In step S22, similar to step S12 in FIG. 5, switching control is performed on 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 to convert the AC power input from the first AC terminal Tac1, the second AC terminal Tac2, and the third AC terminal Tac3 into DC power and output it from the high potential side DC terminal TdcH and the low potential side DC terminal TdcL.

[0071] If the determination in step S20 is negative, the process proceeds to step S23, where it is determined whether or not a single-phase charging control command has been issued. In this embodiment, as shown in Fig. 12, 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 single-phase charging control command has been issued.

[0072] If the determination in step S23 is affirmative, single-phase charging control is performed in steps S24 and S25. More specifically, in step S24, the first to third single-phase charging switches 46-48 are turned on. Also, the third upper and lower arm switches S3H, S3L and the fourth upper and lower arm switches S4H, S4L are turned off. This allows current to flow only via the body diodes in the third upper and lower arm switches S3H, S3L and the fourth upper and lower arm switches S4H, S4L.

[0073] In step S25, similarly to 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 a synchronous manner with each other, with a dead time therebetween, so that the AC power inputted from the first AC terminal Tac1 and the fourth AC terminal Tac4 is converted into DC power and outputted from the high potential side DC terminal TdcH and the low potential side DC terminal TdcL.

[0074] The series connection of the third upper and lower arm switches S3H, S3L is referred to as the third leg, and the series connection of the fourth upper and lower arm switches S4H, S4L is referred to as the fourth leg. During single-phase charging control, a current flows through the fourth leg in addition to the third leg and the third path 43. Therefore, compared to the first embodiment, the current flowing through the third inductor 33 can be reduced, and the rated current (specifically, the temperature rise rated current) of the third inductor 33 can be reduced. This provides the effects of the first embodiment, as well as the effect of making the third inductor 33 smaller.

[0075] <Third embodiment> The third embodiment will be described below with reference to the drawings, focusing on the differences from the second embodiment. In this embodiment, as shown in Fig. 13, the power conversion device 10 includes a three-phase charging switch 49. The three-phase charging switch 49 is provided in a portion of the third path 43 between the third inductor 33 and the third coil 36C. The three-phase charging switch 49 allows bidirectional current flow when it is turned on, and blocks bidirectional current flow when it is turned off.

[0076] The charging control executed by the control device 70 will be described with reference to FIG.

[0077] In step S30, similarly to step S20 in FIG. 10, it is determined whether or not a command for three-phase charging control has been issued.

[0078] If the determination in step S30 is affirmative, three-phase charging control is performed in steps S31 and S32. More specifically, in step S31, the first to third single-phase charging switches 46-48 and the fourth upper and lower arm switches S4H, S4L are turned off, and the three-phase charging switch 49 is turned on (see FIG. 15).

[0079] In step S32, similar to step S12, switching control is performed on 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 to convert the AC power input from the first AC terminal Tac1, the second AC terminal Tac2, and the third AC terminal Tac3 into DC power and output it from the high potential side DC terminal TdcH and the low potential side DC terminal TdcL.

[0080] If the determination in step S30 is negative, the process proceeds to step S33. In step S33, similar to step S23, it is determined whether or not a command for single-phase charging control has been issued.

[0081] If the answer is yes in step S33, single-phase charging control is performed in steps S34 and S35. More specifically, in step S34, the first to third single-phase charging switches 46-48 are turned on, and the three-phase charging switch 49 and the third upper and lower arm switches S3H, S3L are turned off (see FIG. 16).

[0082] In step S35, similarly to 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 alternately in synchronization with each other with a dead time therebetween, so that the AC power inputted from the first AC terminal Tac1 and the fourth AC terminal Tac4 is converted into DC power and outputted from the high potential side DC terminal TdcH and the low potential side DC terminal TdcL.

[0083] In step S35, in a first period in which an AC current flows from the fourth AC terminal Tac4 to the first AC terminal Tac1 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. On the other hand, in 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 is included in the first period or the second period may be determined based on, for example, a detection value of the first current sensor 61.

[0084] In this embodiment, since the three-phase charging switch 49 is turned off during single-phase charging control, no current flows through the third inductor 33. This makes it possible to further reduce the rated current of the third inductor 33, and therefore the third inductor 33 can be made smaller.

[0085] <Other embodiments> Each of the above embodiments may be modified as follows.

[0086] During single-phase charging control, the control device 70 may drive the first and second upper and lower arm switches S1H, S1L, S2H, S2L in an interleaved manner. The interleaved driving is a switching control in which the timing at which the first upper arm switch S1H is switched on and the timing at which the second upper arm switch S2H is switched on are shifted by 180° in electrical angle.

[0087] During the single-phase charging control of the second and third embodiments, 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 may be provided instead of the fourth upper and lower arm switches S4H and S4L. The cathode, which is the high potential side terminal of the upper arm diode, is connected to the high potential side path 30H, and the anode, which is the low potential side terminal of the lower arm diode, is connected to the low potential side path 30L. The anode of the upper arm diode and the cathode of the lower arm diode are connected.

[0088] The power conversion device is not limited to an on-board charger, and may have a configuration as shown in Fig. 17. The power conversion device 10 shown in Fig. 17 is a device used in facilities that handle large power of, for example, megawatts, and includes a four-leg AC-DC conversion circuit that is generally used as an active filter circuit for a three-phase system. Note that in Fig. 17, for convenience, the same reference numerals are used to designate components that correspond to the components shown above.

[0089] The power conversion device 10 includes a common mode filter 135. The common mode filter 135 is a five-phase filter including a first coil 136A, a second coil 136B, a third coil 136C, a fourth coil 136D, and a fifth coil 136E as a "specific coil". That is, the input phase is four phases, whereas the common mode filter 135 is five phases, one phase more. The connection point of the fourth upper and lower arm switches S4H and S4L and the fourth AC terminal Tac4 are connected by a connection path 140. The first to third coils 136A to 136C are provided in the first to third paths 41 to 43, and the fourth coil 136D is provided in the connection path 140.

[0090] There is a possibility that a current larger than that flowing through the first to third paths 41 to 43 flows through the connection path 140. For this reason, the fifth coil 136E is connected in parallel to the fourth coil 136D provided in the connection path 140. This allows the current flowing through the connection path 140 to be distributed to the fourth and fifth coils 136D and 136E, and the rated current of the fourth and fifth coils 136D and 136E can be reduced.

[0091] The power conversion device may have a configuration shown in Fig. 18. The power conversion device 10 shown in Fig. 18 includes a four-leg AC-DC conversion circuit (inverter) that is applied to a three-phase rotating electric machine 200. In Fig. 18, the same reference numerals are used for the configurations corresponding to those shown in Fig. 17 for convenience.

[0092] A first end of the armature winding 201 of the rotary electric machine 200 is connected to the first to third AC terminals Tac1 to Tac3. A second end of the armature winding 201 of each phase is connected at a neutral point. This neutral point is connected to a connection point of the fourth upper and lower arm switches S4H, S4L by a connection path 210.

[0093] There is a possibility that a current larger than that flowing through the first to third paths 41 to 43 flows through the connection path 210. For this reason, the fifth coil 136E is connected in parallel to the fourth coil 136D provided in the connection path 210. This allows the current flowing through the connection path 210 to be distributed to the fourth and fifth coils 136D and 136E.

[0094] In the first to third embodiments, the number of specific coils connected in parallel to the third coil 36C and the number of specific coils connected in parallel to the fourth coil 136D in Fig. 17 and Fig. 18 are not limited to one and may be more than one. Also, the phase of the coil to which the specific coil is connected is not limited to one phase and may be more than one phase excluding all phases.

[0095] The power conversion device 10 may have only the second function out of a first function of converting AC power input via an AC terminal connected to an external AC power source into DC power and outputting the DC power from the DC terminal, and a second function of converting DC power input from the DC terminal into AC power and outputting the AC power from the AC terminal.

[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 freewheel 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, for example, a small-capacity rechargeable storage 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 moving 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. The power conversion device is not limited to a moving body, but may be a stationary device.

[0101] The control unit and the method described in the present disclosure may be realized by a special-purpose computer provided by configuring a processor and a memory programmed to execute one or more functions embodied in a computer program. Alternatively, the control unit and the method described in the present disclosure may be realized by a special-purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the control unit and the method described in the present disclosure may be realized by one or more special-purpose computers configured by a combination of a processor and a memory programmed to execute one or more functions and a processor configured with one or more hardware logic circuits. In addition, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions executed by the computer. [Explanation of symbols]

[0102] 10...power conversion device, 21...three-phase AC power supply, 22...single-phase AC power supply, 31-33...first to third inductors, 46...single-phase charging switch, 70...control device, 35...common mode filter, S1H, S2H, S3H...first to third upper arm switches, S1L, S2L, S3L...first to third lower arm switches.

Claims

1. A plurality of AC terminals (Tac1 to Tac4) for multiple phases; DC terminals (TdcH, TdcL), AC / DC conversion circuits (S1H to S4L) having at least one of a function of converting AC power inputted from the AC terminals into DC power and outputting the DC power from the DC terminals, and a function of converting DC power inputted from the DC terminals into AC power and outputting the AC power from the AC terminals; In a power conversion device (10) comprising: Electrical paths (41 to 43) provided corresponding to each phase and connecting the AC / DC conversion circuit and the AC terminals; A common mode filter (35); Equipped with The common mode filter includes: A coil (36A to 36C) provided in the electrical path of each phase; A specific coil (36D) connected in parallel to at least one of the coils; A core (37) around which each of the coils and the specific coil are wound; having The AC terminals include a first AC terminal (Tac1), a second AC terminal (Tac2), and a third AC terminal (Tac3), The DC terminals include a high potential side DC terminal (TdcH) and a low potential side DC terminal (TdcL), a three-phase AC power source (21) is connectable to the first AC terminal, the second AC terminal, and the third AC terminal, and a single-phase AC power source (22) is connectable to the first AC terminal and the third AC terminal, The AC / DC conversion circuit includes: 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); having The electrical path includes: a first path (41) electrically connecting a connection point between the first upper arm switch and the first lower arm switch and the first AC terminal; a second path (42) electrically connecting a connection point between the second upper arm switch and the second lower arm switch and the second AC terminal; a third path (43) electrically connecting a connection point between the third upper arm switch and the third lower arm switch and the third AC terminal; is provided, A first inductor (31) provided in the first path; a second inductor (32) provided in the second path; a third inductor (33) provided in the third path; Equipped with high potential side terminals of the first, second and third upper arm switches are electrically connected to the high potential side DC terminal, low potential side terminals of the first, second and third lower arm switches are electrically connected to the low potential side DC terminal, The coil constituting the common mode filter (35) is a first coil (36A) provided in the first path closer to the first AC terminal than the first inductor; a second coil (36B) provided in the second path closer to the second AC terminal than the second inductor; a third coil (36C) provided on the third path closer to the third AC terminal than the third inductor; is provided, a single-phase charging switch (46) electrically connecting the first AC terminal and the second AC terminal; A control unit (70); Equipped with The specific coil (36D) is connected in parallel to the third coil, When the control unit determines that the single-phase AC power source is connected to the first AC terminal and the third AC terminal, with the single-phase charging switch turned on, 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 to perform power conversion between the first AC terminal and the third AC terminal and the high potential side DC terminal and the low potential side DC terminal.

2. A plurality of AC terminals (Tac1 to Tac4) for multiple phases; DC terminals (TdcH, TdcL), AC / DC conversion circuits (S1H to S4L) having at least one of a function of converting AC power inputted from the AC terminals into DC power and outputting the DC power from the DC terminals, and a function of converting DC power inputted from the DC terminals into AC power and outputting the AC power from the AC terminals; In a power conversion device (10) comprising: Electrical paths (41 to 43) provided corresponding to each phase and connecting the AC / DC conversion circuit and the AC terminals; A common mode filter (35); Equipped with The common mode filter includes: A coil (36A to 36C) provided in the electrical path of each phase; A specific coil (36D) connected in parallel to at least one of the coils; A core (37) around which each of the coils and the specific coil are wound; having The AC terminals include a first AC terminal (Tac1), a second AC terminal (Tac2), a third AC terminal (Tac3), and a fourth AC terminal (Tac4), The DC terminals include a high potential side DC terminal (TdcH) and a low potential side DC terminal (TdcL), a three-phase AC power source (21) is connectable to the first AC terminal, the second AC terminal, and the third AC terminal, and a single-phase AC power source (22) is connectable to the first AC terminal and the fourth AC terminal, The AC / DC conversion circuit includes: 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 (S4H) and a lower arm rectifier (S4L); having The electrical path includes: a first path (41) electrically connecting a connection point between the first upper arm switch and the first lower arm switch and the first AC terminal; a second path (42) electrically connecting a connection point between the second upper arm switch and the second lower arm switch and the second AC terminal; a third path (43) electrically connecting a connection point between the third upper arm switch and the third lower arm switch and the third AC terminal; is provided, A first inductor (31) provided in the first path; a second inductor (32) provided in the second path; a third inductor (33) provided in the third path; a first single-phase charging switch (46) electrically connecting the first AC terminal and the second AC terminal; A second single-phase charging switch (47); a third single-phase charging switch (48); A control unit (70); Equipped with high potential side terminals of the first, second and third upper arm switches are electrically connected to the high potential side DC terminal, low potential side terminals of the first, second and third lower arm switches are electrically connected to the low potential side DC terminal, The coil constituting the common mode filter (35) is a first coil (36A) provided in the first path closer to the first AC terminal than the first inductor; a second coil (36B) provided in the second path closer to the second AC terminal than the second inductor; a third coil (36C) provided on the third path closer to the third AC terminal than the third inductor; is provided, the second single-phase charging switch electrically connects a connection point between the upper arm rectifier and the lower arm rectifier to a portion of the third path that is closer to the third inductor than the third coil; the third single-phase charging switch electrically connects the fourth AC terminal and a portion of the third path that is closer to the third AC terminal than the third coil; when it is determined that the single-phase AC power source 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 in a state in which the first single-phase charging switch, the second single-phase charging switch, and the third single-phase charging switch are turned on, so as to perform power conversion between the first AC terminal and the fourth AC terminal and the high potential side DC terminal and the low potential side DC terminal; A power conversion device, wherein the specific coil (36D) is connected in parallel with the third coil.

3. a three-phase charging switch (49) provided in a portion of the third path closer to the third inductor than a connection point with the second single-phase charging switch, 3. The power conversion device of claim 2, wherein when the control unit determines that the single-phase AC power source is connected to the first AC terminal and the fourth AC terminal, the control unit turns on the first single-phase charging switch, the second single-phase charging switch, and the third single-phase charging switch and turns off the three-phase charging switch, and 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 to perform power conversion between the first AC terminal and the fourth AC terminal and the high potential side DC terminal and the low potential side DC terminal.

4. The power conversion device according to claim 2 , wherein the upper arm rectifier and the lower arm rectifier allow a current to flow from their own low potential side terminals to their own high potential side terminals.

5. the specific coil is one, The power conversion device according to any one of claims 1 to 3, wherein the rated currents of the first coil, the second coil, the third coil and the specific coil are set to the same value.

6. a first AC terminal (Tac1), a second AC terminal (Tac2) and a third AC terminal (Tac3); 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 to allow a three-phase AC power supply (21) to be connected to the first AC terminal, the second AC terminal, and the third AC terminal, and configured to allow a single-phase AC power supply (22) to be connected to the first AC terminal and the third 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 first path (41) electrically connecting a connection point between the first upper arm switch and the first lower arm switch and the first AC terminal; a second path (42) electrically connecting a connection point between the second upper arm switch and the second lower arm switch and the second AC terminal; a third path (43) electrically connecting a connection point between the third upper arm switch and the third lower arm switch and the third AC terminal; A first inductor (31) provided in the first path; a second inductor (32) provided in the second path; a third inductor (33) provided in the third path; a single-phase charging switch (46) electrically connecting the first AC terminal and the second AC terminal; A common mode filter (35); Equipped with high potential side terminals of the first, second and third upper arm switches are electrically connected to the high potential side DC terminal, low potential side terminals of the first, second and third lower arm switches are electrically connected to the low potential side DC terminal, The common mode filter includes: a first coil (36A) provided in the first path closer to the first AC terminal than the first inductor; a second coil (36B) provided in the second path closer to the second AC terminal than the second inductor; a third coil (36C) provided on the third path closer to the third AC terminal than the third inductor; A specific coil (36D); a core (37) around which the first coil, the second coil, the third coil and the specific coil are wound; having The specific coil (36D) is connected in parallel to the third coil, The computer a process of determining whether the single-phase AC power supply is connected to the first AC terminal and the third 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 single-phase charging switch is turned on when it is determined that the single-phase AC power source is connected to the first AC terminal and the third AC terminal, and power conversion is performed between the first AC terminal and the third AC terminal and the high potential side DC terminal and the low potential side DC terminal; A program to execute.

7. 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 to allow a three-phase AC power supply (21) to be connected to the first AC terminal, the second AC terminal, and the third AC terminal, and configured to allow a single-phase AC power supply (22) to 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 (S4H) and a lower arm rectifier (S4L); a first path (41) electrically connecting a connection point between the first upper arm switch and the first lower arm switch and the first AC terminal; a second path (42) electrically connecting a connection point between the second upper arm switch and the second lower arm switch and the second AC terminal; a third path (43) electrically connecting a connection point between the third upper arm switch and the third lower arm switch and the third AC terminal; A first inductor (31) provided in the first path; a second inductor (32) provided in the second path; a third inductor (33) provided in the third path; a first single-phase charging switch (46) electrically connecting the first AC terminal and the second AC terminal; A second single-phase charging switch (47); a third single-phase charging switch (48); A common mode filter (35); Equipped with high potential side terminals of the first, second and third upper arm switches are electrically connected to the high potential side DC terminal, low potential side terminals of the first, second and third lower arm switches are electrically connected to the low potential side DC terminal, The common mode filter includes: a first coil (36A) provided in the first path closer to the first AC terminal than the first inductor; a second coil (36B) provided in the second path closer to the second AC terminal than the second inductor; a third coil (36C) provided on the third path closer to the third AC terminal than the third inductor; A specific coil (36D); a core (37) around which the first coil, the second coil, the third coil and the specific coil are wound; having the second single-phase charging switch electrically connects a connection point between the upper arm rectifier and the lower arm rectifier to a portion of the third path that is closer to the third inductor than the third coil; the third single-phase charging switch electrically connects the fourth AC terminal and a portion of the third path that is closer to the third AC terminal than the third coil; The specific coil (36D) is connected in parallel to the third coil, 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 in which the first single-phase charging switch, the second single-phase charging switch, and the third single-phase charging switch are turned on when it is determined that the single-phase AC power source is connected to the first AC terminal and the fourth AC terminal; A program to execute.