On-vehicle charging apparatus

Abstract

To configure, at reduced system cost, an on-vehicle charging apparatus that charges an on-vehicle DC power source with power from an external AC power source.SOLUTION: An on-vehicle charging apparatus 10 comprises an AC-DC converter 1 that converts power between AC power and first DC power, and converts power between the AC power and second DC power. The AC-DC converter 1 is a triple active bridge circuit comprising: a transformer T including a primary-side coil T1, a secondary-side first coil T21, and a secondary-side second coil T22; a primary-side bridge circuit 111 connected with the primary-side coil T1; a secondary-side first bridge circuit 112 connected with the secondary-side first coil T21; and a secondary-side second bridge circuit 113 connected with the secondary-side second coil T22. The primary-side bridge circuit 111 is formed of a bi-directional switching element.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an on-board charging device. [Background technology]

[0002] JP2022-503713A discloses an onboard charging device (onboard charger) that charges a DC power source mounted on a vehicle equipped with a rotating electric machine as a driving force source for wheels such as an electric vehicle or a hybrid vehicle while the vehicle is mounted on the vehicle. FIG. 1 of this document shows a schematic block diagram of an onboard charging device that receives power from an external AC power source (110) and charges an onboard DC power source (140). This onboard charging device includes an AC-DC converter (120) that converts AC power supplied from the external AC power source into DC power, and a DC-DC converter (130) that transforms the converted DC power while reducing pulsating components contained in the converted DC power and supplies it to the DC power source.

[0003] FIG. 8 illustrates one form of such an on-board charging device. The AC-DC converter (1) can be configured to include an input inductor (Li) and a full bridge circuit (111). The DC-DC converter (2) can be configured as a dual active bridge (DAB) circuit including a transformer (T), a full bridge circuit (211) arranged on the primary side of the transformer (T), and a full bridge circuit (212) arranged on the secondary side of the transformer (T). The AC-DC converter (1) including the full bridge circuit (111) also functions as a power factor correction (PFC) circuit that improves the power factor of the DC power converted from the AC power. The full bridge circuit (111) is also switched and controlled to suppress pulsation of the second harmonic of the AC power frequency. The DC-DC converter (2) provides a charging current to the DC power source (3) by further reducing the pulsation component of the DC power by the dual active bridge circuit.

[0004] In addition, electric vehicles, which have become increasingly popular in recent years, may be equipped with motors that require a relatively high output (work load) in addition to the rotating electric machine (travel motor) that serves as the driving force source for the wheels. For example, there are motors that drive devices (compressors, etc.) that constitute an air conditioner that cools and heats the vehicle interior, and motors that drive pumps that circulate fluids (e.g., oil) for lubricating and cooling the drive devices for the wheels (travel motors, gear mechanisms, etc.). In addition to a DC power source (first DC power source) connected to the travel motor, a second DC power source may be provided to supply power to these motors. As illustrated in FIG. 9, it is preferable that not only the first DC power source (3) but also the second DC power source (30) can be charged from an external AC power source (4). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2022-503713 Summary of the Invention [Problem to be solved by the invention]

[0006] In the embodiment shown in FIG. 8, the on-board charging device is provided with three full-bridge circuits, and many switching elements are required for the on-board charging device as a whole. When charging multiple DC power sources as in the embodiment shown in FIG. 9, the number of switching elements further increases. In addition, in recent years, the performance of rechargeable secondary batteries has improved significantly, and it is possible that a charging current having a pulsation with a larger amplitude than before will be acceptable during charging. Therefore, it is possible that the need to suppress the pulsation generated during power conversion from AC to DC will decrease compared to the current situation.

[0007] In view of the above background, it is desirable to configure an on-board charging device that charges an on-board DC power supply with power from an external AC power supply while keeping system costs down. [Means for solving the problem]

[0008] In view of the above, an on-board charging device is an on-board charging device that charges a first DC power source and a second DC power source electrically isolated from the first DC power source with power supplied from an external AC power source, and includes an AC / DC converter that converts power between AC power on the external AC power source side and a first DC power on the first DC power source side, and also converts power between AC power on the external AC power source side and a second DC power on the second DC power source side, the AC / DC converter being a triple active bridge circuit including a transformer having a primary coil, a secondary first coil, and a secondary second coil, a primary bridge circuit connected to the primary coil, a secondary first bridge circuit connected to the secondary first coil, and a secondary second bridge circuit connected to the secondary second coil, and the primary bridge circuit is configured with a bidirectional switching element.

[0009] According to this configuration, since the AC-DC converter is configured with a transformer, it is possible to ensure insulation between the external AC power source and the first DC power source, between the external DC power source and the second DC power source, and between the first DC power source and the second DC power source. In this state where insulation is ensured, the first DC power source and the second DC power source are charged by the first DC power and the second DC power converted by the AC-DC converter, respectively, without providing a separate converter for converting power between DC and DC, so that the vehicle-mounted charging device can be configured on a small scale. In addition, since the primary side bridge circuit is configured with bidirectional switching elements, the primary side bridge circuit can be switched by current control using an inductor, not voltage control using a capacitor. Since a capacitor with a large capacity tends to be large in size, it is easy to suppress the size of the vehicle-mounted charging device. In addition, the bidirectional switching elements are easy to realize soft switching accompanied by zero current switching, which makes the current flowing through the switching elements zero during switching. Therefore, it is easy to reduce the loss of the vehicle-mounted charging device and to reduce the system cost. Thus, according to this configuration, an on-board charging device that charges an on-board DC power supply with power from an external AC power supply can be configured with reduced system costs.

[0010] Further features and advantages of the on-board charging device will become apparent from the following description of exemplary and non-limiting embodiments which are given with reference to the drawings. [Brief description of the drawings]

[0011] [Figure 1] A circuit block diagram showing a first example of an in-vehicle charging device. [Diagram 2] A circuit block diagram showing a second example of an in-vehicle charging device. [Diagram 3] A circuit block diagram showing a third example of an in-vehicle charging device. [Figure 4] A circuit block diagram showing a fourth example of an on-board charging device (an example of an on-board charging device that uses a drive control system for a rotating electric machine in the third example). [Diagram 5]A circuit block diagram showing a fifth example of an in-vehicle charging device. [Figure 6] A circuit block diagram showing a sixth example of an on-board charging device (an example of an on-board charging device that uses a drive control system for a rotating electric machine in the fifth example). [Figure 7] Schematic circuit block diagram of a drive control system for a first rotating electric machine [Figure 8] A circuit block diagram showing an example of a conventional in-vehicle charging device. [Figure 9] A circuit block diagram showing another example of a conventional vehicle-mounted charging device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the vehicle-mounted charging device will be described with reference to the drawings. The circuit block diagram of FIG. 1 shows a first example of the vehicle-mounted charging device 10. The vehicle-mounted charging device 10 is a device that charges the first DC power source 3 and the second DC power source 30 with power supplied from an external AC power source 4 while the first DC power source 3 and the second DC power source 30 are mounted on a vehicle, and is a device called an onboard charger. In this embodiment, the first DC power source 3 and the second DC power source 30 are DC power sources that are electrically independent from each other and are insulated from each other. In addition, the vehicle-mounted charging device 10 is a bidirectional power conversion device, and can convert DC power supplied from the first DC power source 3 or the second DC power source 30 into AC power of a commercial frequency and output it. The first DC power source 3 and the second DC power source 30 may have different or the same rated voltages, and may have the same or different storage capacities. However, in this embodiment, the first DC power supply 3 is a so-called high-voltage DC power supply having a rated voltage of about 200 to 400 volts, and the second DC power supply 30 is a so-called low-voltage DC power supply having a rated voltage of about 12 to 50 volts.

[0013] The first DC power source 3 and the second DC power source 30 are configured, for example, by a rechargeable secondary battery (battery) such as a lithium ion battery, an electric double layer capacitor, etc. For example, when the rated voltage of the second DC power source 30 is about 12 to 24 volts, the second DC power source 30 may be a lead storage battery.

[0014] Although not shown in the drawings, when the first DC power source 3 and the second DC power source 30 are lithium ion batteries, for example, a battery management system (BMS) is often provided. A secondary battery such as a lithium ion battery is composed of a plurality of cells (battery cells). The battery management system is a battery management control system that performs the following: (1) prevention of overcharging and overdischarging of cells, (2) prevention of overcurrent flowing through cells, (3) temperature management of cells, (4) calculation of the state of charge (SOC), (5) equalization of cell voltages, etc. As will be described later with reference to FIG. 7, when a battery current sensor 31 and a battery voltage sensor 32 are provided, these sensors may be configured as part of the battery management system.

[0015] The on-board charging device 10 and the first DC power source 3 are configured to be electrically connected and disconnected by a first main contactor 11, and the on-board charging device 10 and the second DC power source 30 are configured to be electrically connected and disconnected by a second main contactor 14. The on-board charging device 10 and the external AC power source 4 are configured to be electrically connected and disconnected by a grid contactor 13. The first main contactor 11, the second main contactor 14, and the grid contactor 13 are, for example, relays. The relays may be mechanical relays or semiconductor relays (solid state relays). The same applies to other contactors described later.

[0016] As shown in Fig. 1, the in-vehicle charging device 10 includes an AC-DC converter 1 that converts power between AC power on the side of an external AC power source 4 and a first DC power on the side of a first DC power source 3, and also converts power between AC power on the side of the external AC power source 4 and a second DC power on the side of a second DC power source 30. An LC filter circuit 1f made of a filter inductor Lf and a filter capacitor Cf is provided at a connection portion of the AC-DC converter 1 with the external AC power source 4 (between a primary side bridge circuit 111 described later and the external AC power source 4). Note that a configuration not including the LC filter circuit 1f is not prohibited.

[0017] The AC-DC converter 1 includes a transformer T having a primary coil T1 and a secondary coil T2. The secondary coil T2 includes a first secondary coil T21 and a second secondary coil T22. A primary circuit 1a including the primary coil T1 is configured on the primary side of the transformer T. A secondary circuit 1b including the first secondary coil T21 and a second secondary coil T22 is configured on the secondary side of the transformer T. The primary circuit 1a includes a primary bridge circuit 111 connected to the primary coil T1 and an LC filter circuit 1f. The secondary circuit 1b includes a secondary first bridge circuit 112 connected to the secondary first coil T21, a secondary second bridge circuit 113 connected to the secondary second coil T22, a secondary first inductor Ls1 arranged between the secondary first coil T21 and the secondary first bridge circuit 112, and a secondary second inductor Ls2 arranged between the secondary second coil T22 and the secondary second bridge circuit 113. That is, the AC-DC converter 1 is a triple active bridge (TAB) circuit including a transformer T having a primary coil T1, a secondary first coil T21, and a secondary second coil T22, a primary bridge circuit 111 connected to the primary coil T1, a secondary first bridge circuit 112 connected to the secondary first coil T21, and a secondary second bridge circuit 113 connected to the secondary second coil T22.

[0018] A first output capacitor Cs1 is arranged on the opposite side of the secondary side first bridge circuit 112 to the secondary side first coil T21. When the first main contactor 11 is closed, the first output capacitor Cs1 is connected in parallel to the first DC power source 3 and functions as a smoothing capacitor that smoothes the output voltage from the AC-DC converter 1 (secondary side first bridge circuit 112). The voltage output from the AC-DC converter 1 may have pulsation of harmonic components of the frequency of the external AC power source 4 superimposed thereon, but the first output capacitor Cs1 reduces the amplitude of this pulsation component. Similarly, a second output capacitor Cs2 is arranged on the opposite side of the secondary side second coil T22 in the secondary side second bridge circuit 113. When the second main contactor 14 is closed, the second output capacitor Cs2 is connected in parallel to the second DC power source 30 and functions as a smoothing capacitor that smoothes the output voltage from the AC-DC converter 1 (secondary side second bridge circuit 113).

[0019] In this embodiment, the switching element 11S constituting the primary side bridge circuit 111 is a bidirectional switching element. That is, the primary side bridge circuit 111 is composed of bidirectional switching elements. The bidirectional switching element is an element that can pass a current in both directions, and has the same withstand voltage for both positive and negative polarity voltages. For this reason, it is easy to construct a current-controlled AC-DC converter using an inductor (filter inductor Lf) as the primary side circuit 1a in the AC-DC converter 1. This inductor acts to pass a constant current. A voltage-controlled AC-DC converter requires a large-capacity capacitor, but a current-controlled AC-DC converter does not require a large-capacity capacitor, and it is possible to reduce component costs and suppress the increase in size of the device. The filter capacitor Cf is a small-capacity capacitor. In addition, the bidirectional switching element is easy to realize soft switching accompanied by zero current switching that makes the current flowing through the switching element zero during switching. Therefore, it is easy to reduce the loss in the vehicle-mounted charging device 10 and to reduce the system costs.

[0020] The switching element 12S constituting the secondary side first bridge circuit 112 and the switching element 13S constituting the secondary side second bridge circuit 113 may not be a bidirectional switching element. In this embodiment, FETs (Field Effect Transistors) are exemplified as the switching elements 12S and 13S. A freewheel diode is connected in parallel to each switching element with the forward direction being the direction from the negative electrode to the positive electrode (the direction from the lower stage to the upper stage). Of course, in the case of using a body diode or in the case of using reverse conduction in a transistor of a wide band gap semiconductor made of enhancement mode gallium nitride (E-GaN), such a freewheel diode may not be provided.

[0021] In this embodiment, the AC-DC converter 1 is configured with the transformer T, so that insulation can be ensured between the external AC power source 4 and the first DC power source 3, between the external AC power source 4 and the second DC power source 30, and between the first DC power source 3 and the second DC power source 30. If the external AC power source 4 is not electrically independent from the first DC power source 3 and the second DC power source 30, the ground is common, and a relatively high leakage current may flow to the ground. Since a user may be present near the vehicle while the first DC power source 3 and the second DC power source 30 are being charged, it is preferable that such leakage current is also taken into consideration. In addition, in a configuration in which the external AC power source 4 is not electrically independent from the first DC power source 3 and the second DC power source 30, when a short circuit failure or the like occurs in the external AC power source 4, a large short circuit current may flow to the first DC power source 3 and the second DC power source 30, and further to the in-vehicle device connected to the first DC power source 3 and the in-vehicle device connected to the second DC power source 30. The in-vehicle charging device 10 of this embodiment is configured to include a dual active bridge circuit using the transformer T, and thereby the external AC power supply 4 is insulated from the first DC power supply 3 and the second DC power supply 30. This makes it easier to ensure the safety of the user while the first DC power supply 3 and the second DC power supply 30 are being charged, and also makes it possible to suppress the impact on the vehicle of a short-circuit failure of the external AC power supply 4 while the first DC power supply 3 and the second DC power supply 30 are being charged.

[0022] The circuit block diagram in Fig. 2 shows a second example of the on-board charging device 10. In the first example, the external AC power supply 4 is a single-phase AC power supply, whereas in the third example, the external AC power supply 4 is a multi-phase AC power supply. Here, the external AC power supply 4 is connected at a neutral point 4N and is configured with three AC power supplies with phase differences of 2π / 3. Corresponding to the three AC power supplies, the grid contactor 13 is also configured with three contacts.

[0023] The primary side circuit 1a of the second example is configured as a three-phase AC / DC converter to convert power from three-phase AC to DC. The primary side bridge circuit 111 is configured to have three arms corresponding to the three phases. Note that, in the second example, the primary side bridge circuit 111 is also configured using bidirectional switching elements. A filter inductor Lf and a filter capacitor Cf are connected to the connection points of the switching elements 11S in the arms of each phase to form an LC filter circuit 1f. The other configurations are the same as those in the first example, so detailed explanations will be omitted.

[0024] The circuit block diagram of FIG. 3 shows a third example of the vehicle-mounted charging device 10. The vehicle-mounted charging device 10 of the third example is configured to further include a DC-DC converter 2 in addition to the AC-DC converter 1 compared to the first example. In recent years, the performance of rechargeable secondary batteries has improved significantly, and it may become acceptable for a current having a pulsation with a larger amplitude than before to flow into the secondary battery during charging. However, when a cheaper secondary battery is used as the first DC power source 3 and the second DC power source 30, it may be preferable to consider the amplitude of the pulsation component. Therefore, in the third example, the vehicle-mounted charging device 10 is configured to further reduce the pulsation of the charging voltage (battery voltage) applied to the first DC power source 3 and the second DC power source 30 from the vehicle-mounted charging device 10 and the charging current (battery current) supplied to the first DC power source 3 and the second DC power source 30 compared to the first example by including the DC-DC converter 2.

[0025] The first and third examples have the same configuration of the AC-DC converter 1, so detailed description will be omitted. The DC-DC converter 2 includes a first chopper circuit 21 that converts the first DC power into a third DC power, and a second chopper circuit 22 that converts the second DC power into a fourth DC power. The first DC power source 3 is charged by the third DC power, and the second DC power source 30 is charged by the fourth DC power. The first output capacitor Cs1, which was disposed between the AC-DC converter 1 and the first DC power source 3 in the first example and functioned as a smoothing capacitor, is disposed between the DC-DC converter 2 and the first DC power source 3 as the output capacitor of the DC-DC converter 2. Similarly, the second output capacitor Cs2 is disposed between the DC-DC converter 2 and the second DC power source 30 as the output capacitor of the DC-DC converter 2. Note that a first DC link capacitor 6 that smoothes the DC voltage (DC link voltage) between the AC-DC converter 1 and the DC-DC converter 2 (first chopper circuit 21) is arranged at the location (DC side of the AC-DC converter 1) where the first output capacitor Cs1 was arranged in the first example. Similarly, a second DC link capacitor 60 that smoothes the DC voltage (DC link voltage) between the AC-DC converter 1 and the DC-DC converter 2 (second chopper circuit 22) is arranged at the location (DC side of the AC-DC converter 1) where the second output capacitor Cs2 was arranged in the first example.

[0026] The first chopper circuit 21 is configured as a step-down chopper including a first switching circuit 211, a first choke coil Le1, and a first output capacitor Cs1, and converts the first DC power into a third DC power. The second chopper circuit 22 is configured as a step-down chopper including a second switching circuit 212, a second choke coil Le2, and a second output capacitor Cs2, and converts the second DC power into a fourth DC power.

[0027] The first switching circuit 211 has a half-bridge configuration with one arm in which switching elements 21S are connected in series on the upper and lower sides. One end of a first choke coil Le1 is connected to the midpoint of the arm, i.e., the connection point between the upper-side switching element 21S and the lower-side switching element 21S. The other end of the first choke coil Le1 is connected to the positive terminal of the first output capacitor Cs1. The first output capacitor Cs1 is connected in parallel to the first DC power source 3 with the first main contactor 11 closed.

[0028] Similarly, the second switching circuit 212 has a half-bridge configuration including one arm in which the upper and lower switching elements 22S are connected in series. One end of the second choke coil Le2 is connected to the midpoint of the arm, i.e., the connection point between the upper switching element 22S and the lower switching element 22S. The other end of the second choke coil Le2 is connected to the positive terminal of the second output capacitor Cs2. The second output capacitor Cs2 is connected in parallel to the second DC power source 30 with the second main contactor 14 closed.

[0029] According to the third example, even if pulsations of harmonic components of the frequency of the external AC power supply 4 remain in the first DC power and the second DC power, the harmonic components can be reduced by the first chopper circuit 21 and the second chopper circuit 22.

[0030] Incidentally, electric vehicles and hybrid vehicles, which have become widespread in recent years, are equipped with an AC rotating electric machine (Traction Motor) as a driving force source for the wheels. Also, unlike vehicles that use a conventional internal combustion engine as a driving force source for the wheels, in electric vehicles and hybrid vehicles, auxiliary machines such as an oil pump and an air conditioner compressor, which were conventionally driven by the driving force of the internal combustion engine, are often driven by a separate AC rotating electric machine (motor for auxiliary machines). Unlike vehicles that are supplied with power from overhead lines such as railways, in automobiles, the AC rotating electric machine is driven by AC power supplied from a DC power source such as a battery mounted on the vehicle via an inverter. The AC rotating electric machine is equipped with multiple phase coils to generate a rotating magnetic field. Also, the inverter that converts power between DC and AC is configured as a bridge circuit using switching elements. When the DC power source that supplies power to the rotating electric machine is supplied with power from an external AC power source and charged, the vehicle is stopped (parked), so the coil of the rotating electric machine and the inverter that drives the rotating electric machine are not used to drive the rotating electric machine. Therefore, by utilizing a coil of a rotating electric machine and an inverter that drives the rotating electric machine in the vehicle-mounted charging device 10, it is possible to suppress an increase in system costs due to mounting the vehicle-mounted charging device 10 on a vehicle.

[0031] The circuit block diagram of FIG. 4 is an example of an in-vehicle charging device 10 using a drive control system of a rotating electric machine, and shows a fourth example of the in-vehicle charging device 10. As is clear from a comparison between FIG. 3 and FIG. 4, the first switching circuit 211 in the first chopper circuit 21 is configured using a first inverter 5 described later. In addition, the first choke coil Le1 in the first chopper circuit 21 is configured using a first stator coil 7 of a first rotating electric machine 70 described later. The first output capacitor Cs1 is connected to a neutral point 7N of the first stator coil 7. Similarly, the second switching circuit 212 in the second chopper circuit 22 is configured using a second inverter 50 described later. In addition, the second choke coil Le2 in the second chopper circuit 22 is configured using a second stator coil 8 of a second rotating electric machine 8M described later. The second output capacitor Cs2 is connected to a neutral point 8N of the second stator coil 8.

[0032] As described above, the rotating electric machine mounted on the vehicle is not limited to a traction motor that drives the wheels, but also includes a motor that drives a compressor of an air conditioner, a motor that drives an electric oil pump, and a motor that drives an electric water pump for circulating cooling water. Here, the term "motor" is used because the focus is on "drive", but the terms "motor" and "rotating electric machine" are synonymous. The on-board air conditioner and the electric oil pump are referred to as auxiliary machines in comparison with the vehicle drive device 9 as the main machine, so in the following description, the motor that serves as the driving force source for the wheels may be referred to as a traction motor, and the motor that serves as the driving force source for the on-board air conditioner and the electric oil pump may be referred to as an auxiliary motor that serves as the driving force source for the auxiliary machines. The first rotating electric machine 70 described above corresponds to the traction motor. The second rotating electric machine 8M corresponds to the auxiliary motor.

[0033] Here, the drive control system of the rotating electric machine will be described. The schematic circuit block diagram of Fig. 7 shows an example of the drive control system of the first rotating electric machine 70. The drive control system of the second rotating electric machine 8M can be easily understood from the description of the drive control system of the first rotating electric machine 70, so here, the drive control system of the first rotating electric machine 70 will be described as a representative example, and the description of the drive control system of the second rotating electric machine 8M will be omitted.

[0034] 7, the vehicle drive device 9 includes a first rotating electric machine 70 that serves as a driving force source for wheels of a hybrid vehicle, an electric vehicle, or the like, and a first inverter 5 that is connected to the first rotating electric machine 70 and a first DC power source 3 to convert power between DC and multiple-phase (here, three-phase) AC. Note that this does not prevent the vehicle drive device 9 from including another driving force source, such as an internal combustion engine (not shown), in addition to the first rotating electric machine 70.

[0035] As shown in FIG. 7, the vehicle drive device 9 includes a control device 80 that controls a first rotating electric machine 70 that is a driving force source for the vehicle, and the control device 80 drives and controls the first rotating electric machine 70 by performing current feedback control. The first rotating electric machine 70 to be driven is an interior permanent magnet type rotating electric machine (IPMSM: Interior Permanent Magnet Synchronous Motor) having a stator in which a first stator coil 7 of multiple phases (N phases, where N is any natural number; in this embodiment, a three-phase form with N=3 is illustrated) is arranged in a stator core, and a rotor in which a permanent magnet is arranged in a rotor core. Such a configuration is well known, and in this embodiment, the stator core, stator, rotor core, rotor, permanent magnets, etc. are not illustrated. In this embodiment, a Y-type (star type) form in which the three-phase first stator coils 7 are short-circuited at a neutral point 7N is illustrated. However, the first rotating electric machine 70 may be, for example, in a form in which two sets of three-phase first stator coils 7 are arranged and driven by six-phase AC. The first rotating electric machine 70 can function both as an electric motor and as a generator. When the first rotating electric machine 70 functions as an electric motor, the first rotating electric machine 70 is in a power running state, and when the first rotating electric machine 70 functions as a generator, the first rotating electric machine 70 is in a regenerative state.

[0036] The first inverter 5 is connected to the first rotating electric machine 70 and the first DC power source 3, and converts power between multiple-phase AC and DC. A pair of DC side terminals of the first inverter 5 are connected to the positive and negative terminals of the first DC power source 3. The multiple-phase AC side terminals of the first inverter 5 are connected to the multiple-phase first stator coils 7, respectively. In this embodiment, the first inverter 5 includes a U-phase arm, a V-phase arm, and a W-phase arm as multiple-phase arms. Each arm is formed by connecting an upper-stage switching element 5U arranged on the positive side and a lower-stage switching element 5L arranged on the negative side in series. The midpoints of each arm, that is, the connection points between the upper-stage switching element 5U and the lower-stage switching element 5L, are connected to the respective first stator coils 7. Specifically, the midpoint of the U-phase arm is connected to the U-phase coil 7u, the midpoint of the V-phase arm is connected to the V-phase coil 7v, and the midpoint of the W-phase arm is connected to the W-phase coil 7w.

[0037] A smoothing capacitor (first DC link capacitor 6) that smoothes the voltage (DC link voltage) between the positive and negative poles is provided on the DC side of the first inverter 5. In addition, a voltage sensor (DC link voltage sensor 61) that detects the DC link voltage is also provided on the DC side of the first inverter 5.

[0038] The first inverter 5 is configured to have a plurality of switching elements 5S. In this embodiment, a FET is used as the switching element 5S. In addition to the FET, an IGBT (Insulated Gate Bipolar Transistor) may be used as the switching element 5S.

[0039] The first inverter 5 is controlled by a control device 80. The control device 80 is constructed with a logic circuit such as a microcomputer as a core component. For example, the control device 80 performs current feedback control based on a target torque (torque command) of the first rotating electric machine 70 provided as a request signal from another control device such as a vehicle control device 90, which is one of the higher-level control devices, to drive the first rotating electric machine 70 via the first inverter 5. The operating voltage of a logic circuit element such as a microcomputer is generally 5 volts or less. In this embodiment, although not shown for simplification, a control signal generated by the logic circuit element is transmitted to the first inverter 5 via a drive circuit. Alternatively, the control device 80 may be considered to include a drive circuit.

[0040] The actual current flowing through the first stator coil 7 of each phase of the first rotating electric machine 70 is detected by a current sensor (motor current sensor 81), and the control device 80 acquires the detection result. In addition, the magnetic pole position (electrical angle) of the rotor of the first rotating electric machine 70 at each point in time and the rotation speed (angular velocity) of the rotor are detected by a rotation sensor 82 such as a resolver or an inductive position sensor, and the control device 80 acquires the detection result. The control device 80 executes current feedback control using the detection results of the motor current sensor 81 and the rotation sensor 82. The control device 80 is configured to have various functional units for current feedback control, and each functional unit is realized by cooperation between hardware such as a microcomputer and software (program).

[0041] As described above, the first rotating electric machine 70 connected to the first DC power source 3 via the first inverter 5 functions as an electric motor by the power supplied from the first DC power source 3, and can also function as a generator to charge the first DC power source 3. For example, in a hybrid vehicle, it is possible to supply mechanical energy to the first rotating electric machine 70 by the power of an internal combustion engine or the like to cause the first rotating electric machine 70 to generate electricity, but there are cases where the first DC power source 3 cannot be sufficiently charged because there are few opportunities for power generation. Also, in an electric vehicle equipped with only the first rotating electric machine 70 as a driving force source, power generation is limited to mechanical energy from the wheels during inertial running, and the first DC power source 3 cannot be sufficiently charged in many cases. Also, in a hybrid vehicle, it may be more energy efficient to supply power from an external source than to have the first rotating electric machine 70 generate electricity. For this reason, it is preferable that the first DC power source 3 be configured to be chargeable by an external power source when the first DC power source 3 is equipped on the vehicle.

[0042] When the first DC power supply 3 is charged by the external AC power supply 4, it is preferable that the vehicle is equipped with an on-board charging device 10 as in this embodiment. As described above with reference to the first to third examples, the on-board charging device 10 equipped with a power conversion circuit tends to have a large circuit size, but there are fewer opportunities to charge the first DC power supply 3 compared to driving the wheels. When the first DC power supply 3 is charged by the external AC power supply 4, the vehicle is stopped (parked). In the fourth example, the on-board charging device 10 is configured using a first inverter 5 and a first stator coil 7.

[0043] As described above, the vehicle-mounted charging device 10 of this embodiment is configured to be able to charge the first DC power source 3 and the second DC power source 30. The first rotating electric machine 70 and the first inverter 5 are insulated from the primary side circuit 1a of the AC-DC converter 1 by the transformer T. Similarly, the second rotating electric machine 8M and the second inverter 50 are insulated from the primary side circuit 1a of the AC-DC converter 1 by the transformer T. Meanwhile, the first rotating electric machine 70 and the first inverter 5 are connected to the first DC power source 3 connected to the first chopper circuit 21, and the second rotating electric machine 8M and the second inverter 50 are connected to the second DC power source 30 connected to the second chopper circuit 22. In other words, the first DC power source 3 is connected to the first rotating electric machine 70 having the first stator coils 7 of multiple phases connected to each other at the neutral point 7N via the first inverter 5 that converts power between DC and AC. In addition, a second DC power supply 30 is connected to a second rotating electric machine 8M having multiple phases of second stator coils 8 connected to each other at a neutral point 8N via a second inverter 50 that converts power between DC and AC.

[0044] Therefore, in the fourth example, the first chopper circuit 21 is configured using the first inverter 5 and the first stator coil 7, and the second chopper circuit 22 is configured using the second inverter 50 and the second stator coil 8. Specifically, the first chopper circuit 21 is configured to include a first switching circuit configured using the first inverter 5, a first choke coil configured using the first stator coil 7 of multiple phases, and a first output capacitor Cs1 connected to the neutral point 7N of the first stator coil 7 of multiple phases. The second chopper circuit 22 is configured to include a second switching circuit configured using the second inverter 50, a second choke coil configured using the second stator coil 8 of multiple phases, and a second output capacitor Cs2 connected to the neutral point 8N of the second stator coil 8 of multiple phases.

[0045] The first inverter 5 is configured with one phase of arms in which the upper-stage switching element 5U and the lower-stage switching element 5L are connected in series, the number of which corresponds to the number of phases of the multi-phase AC (here, three for three phases), in parallel. Similarly, the second inverter 50 is configured with one phase of arms in which the upper-stage switching element 50U and the lower-stage switching element 50L are connected in series, the number of which corresponds to the number of phases of the multi-phase AC (here, three for three phases), in parallel. When the first inverter 5 functions as a switching circuit of the first chopper circuit 21, all the upper-stage switching elements 5U of the arms of the multi-phase are simultaneously and similarly controlled to be turned on and off, and all the lower-stage switching elements 5L of the arms of the multi-phase are simultaneously and similarly controlled to be turned on and off. Therefore, the first inverter 5 having multiple arms apparently functions as a first switching circuit 211 configured with one arm in which the upper-stage switching element 5U and the lower-stage switching element 5L are connected in series. Similarly, the second inverter 50 apparently functions as a second switching circuit 212 configured with one arm in which an upper-stage switching element 50U and a lower-stage switching element 50L are connected in series.

[0046] The first stator coil 7 and the second stator coil 8 of each of the multiple phases have one end connected to the midpoint of the arm corresponding to the respective phase, and the other end connected to the respective neutral point 7N and neutral point 8N. As described above, since each arm of the multiple phases is similarly switched and controlled, the first stator coil 7 of each phase has a current flowing between the arm and the neutral point 7N in the same manner, and the second stator coil 8 of each phase has a current flowing between the arm and the neutral point 8N in the same manner. Therefore, the first stator coil 7 of the multiple phases can be regarded as one coil, and the first stator coil 7 functions as a first choke coil Le1 with one end connected to the midpoint of the switching circuit in the chopper circuit and the other end connected to the output capacitor Cs. The second stator coil 8 of the multiple phases can also be regarded as one coil, and functions as a second choke coil Le2.

[0047] As shown in FIG. 4, the on-board charging device 10 of the fourth example includes a first function switching contactor 12 and a second function switching contactor 15 for switching between the control function of the rotating electric machine and the charging function of the DC power source in addition to the first main contactor 11, the second main contactor 14, and the grid contactor 13. These contactors are controlled by the control device 80, or the control device 80 and the vehicle control device 90, or a control device (not shown) that controls the second rotating electric machine 8M in addition to the above. The contactors of the first to third examples are also controlled by the vehicle control device 90 or a control device (not shown) that controls the on-board charging device 10 in the same manner. As described above with reference to FIG. 7, the control device 80 and the vehicle control device 90 are also included in the drive control system of the rotating electric machine, and it can be said that the control device 80, the vehicle control device 90, and the control device (not shown) that controls the second rotating electric machine 8M are also used in common for the drive control of the rotating electric machine and the charge control by the on-board charging device 10. As is apparent from FIGS. 3, 4 and 7, the first DC link capacitor 6 and the second DC link capacitor 60 can also be said to be used in common for drive control of the rotating electric machine and charge control by the on-board charging device 10.

[0048] As described above with reference to FIG. 7, the first main contactor 11 is installed so as to be able to electrically connect and disconnect the first DC power source 3 and the first inverter 5. When the first inverter 5 and the first stator coil 7 of the first rotating electric machine 70 are also used as the in-vehicle charging device 10, the connection form to the first DC power source 3 is switched. For this reason, the first main contactor 11 has a first main contactor first contact 11a and a first main contactor second contact 11b. When the first inverter 5 functions as the vehicle drive device 9, the first main contactor first contact 11a is closed and the first main contactor second contact 11b is opened. When the first inverter 5 functions as the in-vehicle charging device 10, the first main contactor second contact 11b is closed and the first main contactor first contact 11a is opened. When the first DC power source 3 is not being charged and the vehicle is parked, the first main contactor 11 can be put into an open state by putting both the first main contactor first contact 11a and the first main contactor second contact 11b into an open state.

[0049] In a closed state, the first function switching contactor 12 electrically connects the output of the first chopper circuit 21 serving as the DC-DC converter 2 to the first DC power source 3. Specifically, in a closed state, the first function switching contactor 12 connects the neutral point 7N to the positive electrode of the first DC power source 3, and also connects the positive terminal of the first output capacitor Cs1 to the positive electrode of the first DC power source 3. As described above, the grid contactor 13 electrically connects and disconnects the AC-DC converter 1 to the external AC power source 4.

[0050] When the first inverter 5 is used for drive control of the first rotating electric machine 70, the first main contactor first contact 11a is closed, and the first function switching contactor 12 and the grid contactor 13 are controlled to be in an open state, and power is converted between the first DC power source 3 and the first rotating electric machine 70 via the first inverter 5. When the first inverter 5 is used as the in-vehicle charging device 10, the first main contactor second contact 11b is closed, and the first function switching contactor 12 and the grid contactor 13 are controlled to be in a closed state, and the first DC power source 3 is charged by the external AC power source 4.

[0051] As shown in FIG. 4, the second main contactor 14 is installed so as to be able to electrically connect and disconnect the second DC power source 30 and the second inverter 50. When the second inverter 50 and the second stator coil 8 of the second rotating electric machine 8M are also used as the in-vehicle charging device 10, the connection form to the second DC power source 30 is switched. For this reason, the second main contactor 14 has a second main contactor first contact 14a and a second main contactor second contact 14b. When the second inverter 50 functions as the vehicle drive device 9, the second main contactor first contact 14a is closed and the second main contactor second contact 14b is opened. When the second inverter 50 functions as the in-vehicle charging device 10, the second main contactor second contact 14b is closed and the second main contactor first contact 14a is opened. When the second DC power source 30 is not being charged and, for example, the vehicle's main switch (ignition switch) is turned off and the accessories are also stopped, the second main contactor 14 can be opened by opening both the second main contactor first contact 14a and the second main contactor second contact 14b.

[0052] In a closed state, the second function switching contactor 15 electrically connects the output of the second chopper circuit 22 serving as the DC-DC converter 2 to the second DC power source 30. Specifically, in a closed state, the second function switching contactor 15 connects the neutral point 8N to the positive electrode of the second DC power source 30, and also connects the positive terminal of the second output capacitor Cs2 to the positive electrode of the second DC power source 30. As described above, the grid contactor 13 electrically connects and disconnects the AC-DC converter 1 to the external AC power source 4.

[0053] When the second inverter 50 is used for driving control of the second rotating electric machine 8M, the second main contactor first contact 14a is closed, and the second function switching contactor 15 and the grid contactor 13 are controlled to be in an open state, and power is converted between the second DC power source 30 and the second rotating electric machine 8M via the second inverter 50. When the second inverter 50 is used as the in-vehicle charging device 10, the second main contactor second contact 14b is closed, and the second function switching contactor 15 and the grid contactor 13 are controlled to be in a closed state, and the second DC power source 30 is charged by the external AC power source 4.

[0054] In this way, by simply changing the connection form to the inverter and the stator coil, a circuit can be realized that can switch between a function of driving and controlling the rotating electric machine and a function of charging the DC power source with the external AC power source 4. That is, the DC power source connected to the rotating electric machine can be used to charge both the coil of the rotating electric machine and the inverter that drives and controls the rotating electric machine. By using these functions in combination, the vehicle-mounted charging device 10 can be configured on a small scale.

[0055] The second DC power source 30 can also be charged by power supplied from the first DC power source 3 or the first rotating electric machine 70. For example, in a state where the external AC power source 4 is not connected and the first DC power source 3 is not charged (the grid contactor 13 and the first function switching contactor 12 are in an open state), the first main contactor first contact 11a is closed for the first DC power source 3, and the second main contactor second contact 14b and the second function switching contactor 15 are closed for the second DC power source 30. In this state, the first rotating electric machine 70 runs by power supplied from the first DC power source 3, or, if the first rotating electric machine 70 is equipped with wheels or an internal combustion engine, generates power by power transmitted from the internal combustion engine and runs in a regenerative manner to supply power to the first DC power source 3.

[0056] The secondary-side first bridge circuit 112 of the AC-DC converter 1 is connected to the first DC link capacitor 6, the first DC power source 3, and the DC side of the first inverter 5. Power from the first DC link capacitor 6, the first DC power source 3, and the first inverter 5 can be transmitted to the secondary-side second coil T22 via the secondary-side first coil T21 to which the secondary-side first bridge circuit 112 is connected, and the primary-side coil T1. The secondary-side second coil T22 is connected to the secondary-side second bridge circuit 113, and the secondary-side second bridge circuit 113 is connected to the second DC link capacitor 60 and the second chopper circuit 22. The power supplied from the secondary-side second bridge circuit 113 is supplied to the second DC power source 30 via the second chopper circuit 22 as described above.

[0057] When the second rotating electric machine 8M is an auxiliary motor for an air conditioner, and the air conditioner is not in use, as described above, the second DC power source 30 can be charged by the power of the first DC power source 3 (including both the power supplied from the first DC power source 3 and the power regenerated to the first DC power source 3) without connecting the external AC power source 4. Here, an auxiliary motor for an air conditioner is exemplified, but the same applies when the second rotating electric machine 8M is another auxiliary motor.

[0058] Further, in the above description, the second DC power source 30 is charged by the power of the first DC power source 3 in the vehicle-mounted charging device 10 illustrated in Fig. 4, but even in the vehicle-mounted charging device 10 illustrated in Figs. 1 to 3 which does not use a rotating electric machine, the second DC power source 30 can be charged by the power of the first DC power source 3 (in this case, the power supplied from the first DC power source 3) without connecting the external AC power source 4. The open / closed state of the contactor and the flow of power are as described above with reference to Fig. 4, and therefore detailed description thereof will be omitted.

[0059] In addition, in the present embodiment, the first DC power source 3 is a high-voltage DC power source, and the second DC power source 30 is a low-voltage DC power source, so that the second DC power source 30 is charged with the power of the first DC power source 3. However, as described above, the first DC power source 3 and the second DC power source 30 may have the same rated voltage and the same storage capacity. In addition, the first rotating electric machine 70 and the second rotating electric machine 8M may be, for example, both driving motors (such as a two-motor automobile or an open-winding type rotating electric machine having two inverters) or both auxiliary motors. Therefore, the present embodiment is not limited to a configuration in which the second DC power source 30 is charged with the power of the first DC power source 3, and may be a configuration in which the first DC power source 3 is charged with the power of the second DC power source 30. Naturally, it may be possible to switch between charging the second DC power supply 30 with the power of the first DC power supply 3 and charging the first DC power supply 3 with the power of the second DC power supply 30.

[0060] As described above, the second DC power supply 30 can be charged by power supplied from the first DC power supply 3 or the first rotating electric machine 70, and the first DC power supply 3 can be charged by power supplied from the second DC power supply 30 or the second rotating electric machine 8M. Therefore, the third example of the in-vehicle charging device 10 shown in Fig. 3 may be configured as the fifth example shown in Fig. 5, and the fourth example of the in-vehicle charging device 10 shown in Fig. 4 may be configured as the sixth example shown in Fig. 6.

[0061] The on-board charging device 10 of the fifth example shown in FIG. 5 includes a switching circuit (first switching circuit 211), a choke coil (first choke coil Le1), and an output capacitor (first output capacitor Cs1) in comparison with the on-board charging device 10 of the first example, and further includes a chopper circuit (first chopper circuit 21) that converts the first DC power into the third DC power. In the place where the first output capacitor Cs1 was arranged in the first example, a first DC link capacitor 6 is arranged as in the third example. It can be said that the on-board charging device 10 of the fifth example is configured without including the second chopper circuit 22 in relation to the on-board charging device 10 of the third example. And, the on-board charging device 10 of the fifth example charges the first DC power source 3 with the third DC power, and charges the second DC power source 30 with the second DC power.

[0062] By providing the DC-DC converter 2 having a chopper circuit (for example, the first chopper circuit 21), the pulsation component in the third DC power can be suppressed compared to the first DC power. In addition, the third DC power and the second DC power are both powers on the secondary side of the transformer T. The primary coil T1 and the secondary first coil T21 are electromagnetically coupled, and the pulsation of the third DC power in the first chopper circuit 21 connected to the secondary first coil T21 is suppressed, so that the pulsation of the DC power (second DC power) appearing in the secondary second coil T22 electromagnetically coupled to the primary coil T1 is also suppressed.

[0063] In the fifth example of the on-board charging device 10 described above with reference to Fig. 5, the first DC power source 3 is charged with DC power obtained by two-stage power conversion from AC power via the AC-DC converter 1 and the DC-DC converter 2, and the second DC power source 30 is charged with DC power obtained by one-stage power conversion from AC power only via the AC-DC converter 1. However, although not shown in the drawings, a configuration may also be adopted in which the second DC power source 30 is charged with DC power obtained by two-stage power conversion from AC power via the AC-DC converter 1 and the DC-DC converter 2, instead of the first DC power source 3, and the first DC power source 3 is charged with DC power obtained by one-stage power conversion from AC power only via the AC-DC converter 1.

[0064] That is, the in-vehicle charging device 10 may further include a switching circuit (second switching circuit 212), a choke coil (second choke coil Le2), and an output capacitor (second output capacitor Cs2) in addition to the first example configuration, and may further include a chopper circuit (second chopper circuit 22) that converts the second DC power into a fourth DC power. In the location where the second output capacitor Cs2 was arranged in the first example, a second DC link capacitor 60 is arranged as in the third example. In relation to the third example configuration, it can be said that the in-vehicle charging device 10 is configured without including the first chopper circuit 21. In this case, the in-vehicle charging device 10 charges the first DC power source 3 with the first DC power, and charges the second DC power source 30 with the fourth DC power.

[0065] In this manner, the in-vehicle charging device 10 of the fifth example includes a switching circuit (the first switching circuit 211 or the second switching circuit 212), a choke coil (the first choke coil Le1 or the second choke coil Le2), and an output capacitor (the first output capacitor Cs1 or the second output capacitor Cs2), and includes a chopper circuit (the first chopper circuit 21 or the second chopper circuit 22) that converts the first DC power into the third DC power or converts the second DC power into the fourth DC power. When the chopper circuit (the first chopper circuit 21) converts the first DC power into the third DC power, the first DC power source 3 is charged with the third DC power, and the second DC power source 30 is charged with the second DC power. When the chopper circuit (second chopper circuit 22) converts the second DC power into the fourth DC power, the first DC power source 3 is charged with the first DC power, and the second DC power source 30 is charged with the fourth DC power.

[0066] By providing the DC-DC converter 2 having a chopper circuit (first chopper circuit 21) between the AC-DC converter 1 and the first DC power source 3, the pulsation component in the third DC power can be suppressed compared to the first DC power. The third DC power and the second DC power are both powers on the secondary side of the transformer T. The primary coil T1 and the secondary first coil T21 are electromagnetically coupled, and the pulsation of the third DC power in the first chopper circuit 21 connected to the secondary first coil T21 is suppressed, so that the pulsation of the DC power (second DC power) appearing in the secondary second coil T22 electromagnetically coupled to the primary coil T1 is also suppressed. Similarly, by providing the DC-DC converter 2 having a chopper circuit (second chopper circuit 22) between the AC-DC converter 1 and the second DC power source 30, the pulsation component in the fourth DC power can be suppressed compared to the second DC power. The fourth DC power and the first DC power are both powers on the secondary side of the transformer T. The primary coil T1 and the secondary first coil T21 are electromagnetically coupled, and the pulsation of the fourth DC power in the second chopper circuit 22 connected to the secondary second coil T22 is suppressed, so that the pulsation of the DC power (first DC power) appearing in the secondary first coil T21 electromagnetically coupled to the primary coil T1 is also suppressed. That is, by providing the DC-DC converter 2 having a chopper circuit either between the secondary first bridge circuit 112 and the first DC power source 3 or between the secondary second bridge circuit 113 and the second DC power source 30, the pulsation of the DC power for charging supplied to both the first DC power source 3 and the second DC power source 30 can be appropriately suppressed.

[0067] Similarly to the relationship between the third and fourth examples, in the fifth example, as in the on-board charging device 10 of the sixth example described later with reference to FIG. 6, for example, a stator coil of a rotating electric machine and an inverter driving the rotating electric machine can be used for the switching circuit and choke coil constituting the chopper circuit. That is, when a DC power source to be charged via a chopper circuit (first chopper circuit 21 or second chopper circuit 22) among the first DC power source 3 and the second DC power source 30 is connected to a rotating electric machine (first rotating electric machine 70 or second rotating electric machine 8M) having a multi-phase stator coil (first stator coil 7 or second stator coil 8) connected to each other at a neutral point (7N or 8N) via an inverter (first inverter 5 or second inverter 50) that converts power between DC and AC, the chopper circuit (first chopper circuit 21 or second chopper circuit 22) is connected to the inverter (first inverter 5 or second inverter 50). The inverter circuit may be configured to include a switching circuit (first switching circuit 211 or second switching circuit 212) configured using a multi-phase stator coil (first stator coil 7 or second stator coil 8), a choke coil (first choke coil Le1 or second choke coil Le2) configured using a multi-phase stator coil (first stator coil 7 or second stator coil 8), and an output capacitor (first output capacitor Cs1 or second output capacitor Cs2) connected to the neutral point (7N or 8N) of the multi-phase stator coil (first stator coil 7 or second stator coil 8).

[0068] FIG. 6 shows a sixth example of the vehicle-mounted charging device 10. In the case where the first DC power source 3 charged via the first chopper circuit 21 is connected to the first rotating electric machine 70 having the first stator coils 7 of multiple phases connected to each other at the neutral point 7N via the first inverter 5 for converting power between DC and AC, the first chopper circuit 21 is configured to include the first switching circuit 211 configured using the first inverter 5, the first choke coil Le1 configured using the first stator coils 7 of multiple phases, and the first output capacitor Cs1 connected to the neutral point 7N of the first stator coils 7 of multiple phases. Details of the function switching method and the like are as described above with reference to FIG. 4 and FIG. 7 for the vehicle-mounted charging device 10 of the fourth example, and therefore will not be described in detail.

[0069] Similarly, although not shown in the figure, when a first DC power source 3 charged via a second chopper circuit 22 is connected to a second rotating electric machine 8M having a multi-phase second stator coil 8 connected to each other at a neutral point 8N via a second inverter 50 that converts power between DC and AC, the second chopper circuit 22 may be configured to include a second switching circuit 212 configured using the second inverter 50, a second choke coil Le2 configured using the multi-phase second stator coil 8, and a second output capacitor Cs2 connected to the neutral point 8N of the multi-phase second stator coil 8.

[0070] In other words, the DC power source connected to the rotating electric machine can be used to charge the coil of the rotating electric machine and the inverter that drives and controls the rotating electric machine. By using these in combination, the vehicle-mounted charging device 10 can be configured on a small scale.

[0071] In recent years, it has been proposed to use the DC power source of an electric vehicle or a hybrid vehicle as an emergency power source in the event of a disaster or the like. The first chopper circuit 21 and the second chopper circuit 22 are bidirectional chopper circuits, which function as a step-down converter from the AC-DC converter 1 to the first DC power source 3 and the second DC power source 30, and function as a step-up converter from the first DC power source 3 and the second DC power source 30 to the AC-DC converter 1 (which performs DC-AC conversion in this case). As shown in FIG. 1 and other figures, the AC-DC converter 1 includes a full bridge circuit, so that the AC-DC converter 1 can function not only as a function of converting AC to DC, but also as a bidirectional power converter having a function of converting DC to AC. That is, the AC-DC converter 1 can perform DC-AC conversion, and commercial AC power can be output from the AC-DC converter 1, and the first DC power source 3 and the second DC power source 30 can be used as emergency power sources.

[0072] When the in-vehicle charging device 10 charges the first DC power source 3 and the second DC power source 30 using the external AC power source 4, the AC-DC converter 1 functions as a triple active bridge AC-DC boost converter (AC / DC TAB Boost Converter), and the DC-DC converter 2 functions as a DC / DC Buck Converter. When the in-vehicle charging device 10 functions as an emergency AC power source that outputs AC power using power stored in the first DC power source 3 and the second DC power source 30, the DC-DC converter 2 functions as a DC / DC Boost Converter, and the AC-DC converter 1 functions as a triple active bridge DC-AC Buck Converter.

[0073] As described above by way of example of various aspects, according to the present embodiment, an on-board charging device that charges an on-board DC power supply with power from an external AC power supply can be configured while keeping system costs down. [Explanation of symbols]

[0074] 1: AC-DC converter, 3: first DC power source, 4: external AC power source, 4N: neutral point, 5: first inverter (inverter), 7: first stator coil (stator coil), 7N: neutral point, 8: second stator coil (stator coil), 8M: second rotating electric machine (rotating electric machine), 8N: neutral point, 10: on-board charging device, 21: first chopper circuit (chopper circuit), 22: second chopper circuit (chopper circuit), 30: second DC power source (DC power source), 50: second inverter (inverter), 70: first rotating electric machine (rotating electric machine), 111 : primary side bridge circuit, 112: secondary side first bridge circuit, 113: secondary side second bridge circuit, 211: first switching circuit (switching circuit), 212: second switching circuit (switching circuit), Cs1: first output capacitor (output capacitor), Cs2: second output capacitor (output capacitor), Le1: first choke coil (choke coil), Le2: second choke coil (choke coil), T: transformer, T1: primary side coil, T21: secondary side first coil, T22: secondary side second coil

Claims

1. An in-vehicle charging device that charges a first DC power source and a second DC power source electrically insulated from the first DC power source with power supplied from an external AC power source, an AC / DC converter that converts power between AC power on the external AC power supply side and a first DC power on the first DC power supply side, and converts power between AC power on the external AC power supply side and a second DC power on the second DC power supply side, The AC / DC converter comprises: a transformer including a primary coil, a first secondary coil, and a second secondary coil; A primary bridge circuit connected to the primary coil; a secondary side first bridge circuit connected to the secondary side first coil; a secondary side second bridge circuit connected to the secondary side second coil; A triple active bridge circuit comprising: The primary bridge circuit is configured with a bidirectional switching element.

2. a first chopper circuit including a first switching circuit, a first choke coil, and a first output capacitor, and configured to convert the first DC power into a third DC power; a second chopper circuit including a second switching circuit, a second choke coil, and a second output capacitor, and configured to convert the second DC power into a fourth DC power; charging the first DC power source with the third DC power; The vehicle-mounted charging device according to claim 1 , wherein the second DC power source is charged with the fourth DC power.

3. a first rotating electric machine including a first stator coil of a plurality of phases connected to each other at a neutral point, the first DC power source being connected via a first inverter that converts power between DC and AC; the second DC power supply is connected to a second rotating electric machine including a second stator coil of a plurality of phases connected to each other at a neutral point via a second inverter that converts power between DC and AC; The first chopper circuit includes: the first switching circuit configured using the first inverter; The first choke coil is configured using the first stator coil of a plurality of phases; the first output capacitor connected to a neutral point of the first stator coil of a plurality of phases, The second chopper circuit is the second switching circuit configured using the second inverter; The second choke coil is configured using the second stator coil of a plurality of phases; the second output capacitor connected to a neutral point of the second stator coil of a plurality of phases, The vehicle-mounted charging device according to claim 2 .

4. a chopper circuit including a switching circuit, a choke coil, and an output capacitor, and configured to convert the first DC power into a third DC power or convert the second DC power into a fourth DC power; When the chopper circuit converts the first DC power into the third DC power, charging the first DC power source with the third DC power; charging the second DC power source with the second DC power; When the chopper circuit converts the second DC power into the fourth DC power, charging the first DC power source with the first DC power; The vehicle-mounted charging device according to claim 1 , wherein the second DC power source is charged with the fourth DC power.

5. a rotating electric machine including a plurality of stator coils connected to each other at a neutral point, the DC power source being one of the first DC power source and the second DC power source and being charged via the chopper circuit is connected via an inverter that converts power between DC and AC; The chopper circuit includes: The switching circuit is configured using the inverter; and The choke coil is configured using the stator coils of multiple phases; The on-board charging device according to claim 4 , further comprising: the output capacitor connected to a neutral point of the stator coils of a plurality of phases.

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