Onboard charger

Abstract

To configure an onboard charger for charging an onboard DC power supply using power from an external AC power supply, while suppressing system costs.SOLUTION: An AC-DC converter 1 comprising a triple active bridge circuit comprises a primary side bridge circuit 111 comprising a first leg and a second leg, each of which has two switching elements 11S connected in series, and a third leg which has two switching elements 11S connected in series or two capacitors Cdc1, Cdc2 connected in series. The midpoint a of the first leg is connected to a one end side of a primary side coil T1, the midpoint b of the second leg is connected to the other end side of the primary side coil T1, the midpoint N of the third leg is connected to a first end of an external AC power supply 4, and a second end of the external AC power supply 4 is connected at least one of the midpoint a of the first leg and the midpoint b of the second leg via a filter inductor Lf.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. 14 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 (amount of work) in addition to a rotating electric machine (traction motor) that serves as a driving force source for the wheels. For example, a motor that drives a device (such as a compressor) that constitutes an air conditioner that cools and heats the vehicle interior, and a motor that drives a pump that circulates a fluid (such as oil) for lubricating and cooling a driving device for the wheels (traction motor, gear mechanism, etc.). In order to supply power to these motors, in addition to a DC power supply (first DC power supply) connected to the traction motor, a second DC power supply may also be provided. As illustrated in FIG. 15, it is preferable that not only the first DC power supply (3) but also the second DC power supply (30) can be charged from an external AC power supply (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. 14, the on-board charging device has 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. 15, 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 insulated 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, the primary bridge circuit including a first leg in which two switching elements are connected in series, and a second leg in which two switching elements are connected in series. a second leg having a switching element connected in series to the primary coil, and a third leg having two switching elements connected in series to the primary coil, a midpoint of the first leg being connected to one end of the primary coil, a midpoint of the second leg being connected to the other end of the primary coil, a midpoint of the third leg being connected to a first end which is one end of the external AC power supply, and a second end which is the other end of the external AC power supply being connected to at least one of the midpoint of the first leg and the midpoint of the second leg via a filter inductor, and the triple active bridge circuit is switched-controlled to generate a unity power factor input grid current with a minimum total harmonic distortion, and to generate a first battery voltage and a second battery voltage with a minimum pulsating component in a first battery current flowing in the first DC power supply and a second battery current flowing in the second DC power supply.

[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 AC 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 that converts power between DC and DC, so that the in-vehicle charging device can be configured on a small scale. Therefore, according to this configuration, it is possible to suppress the system cost of an in-vehicle charging device that charges an in-vehicle DC power source with power from an external AC power source.

[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 modification of the first example of the in-vehicle charging device. [Figure 4] A circuit block diagram showing a modified example of the second example of the in-vehicle charging device. [Diagram 5] A circuit block diagram showing a third example of an in-vehicle charging device. [Figure 6] A circuit block diagram showing a fourth example of an in-vehicle charging device. [Figure 7] A circuit block diagram showing a fifth example of an in-vehicle charging device. [Figure 8] Schematic circuit block diagram of a drive control system for a first rotating electric machine [Figure 9] A circuit block diagram showing a sixth example of an in-vehicle charging device. [Figure 10] A circuit block diagram showing a seventh example of an in-vehicle charging device. [Figure 11] A circuit block diagram showing an eighth example of an in-vehicle charging device. [Figure 12] A circuit block diagram showing a ninth example of an in-vehicle charging device. [Figure 13] Circuit block diagram showing a tenth example of an in-vehicle charging device [Figure 14] A circuit block diagram showing an example of a conventional in-vehicle charging device. [Figure 15] 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, for example, when the first DC power source 3 and the second DC power source 30 are lithium ion batteries, 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 (1) prevention of overcharging and overdischarging of cells, (2) prevention of overcurrent flowing through cells, (3) cell temperature management, (4) calculation of the state of charge (SOC), (5) equalization of cell voltages, and the like. As will be described later with reference to FIG. 8, 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] 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. A filter inductor Lf 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). The filter inductor Lf can be arranged as a parallel split inductor (a first filter inductor Lf1 and a second filter inductor Lf2).

[0017] The AC-DC converter 1 includes a transformer T including a primary coil T1 and two secondary coils (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 a filter inductor. The secondary circuit 1b includes a first secondary bridge circuit 112 connected to the first secondary coil T21 and a second secondary bridge circuit 113 connected to the second secondary coil T22. That is, the AC-DC converter 1 is a triple active bridge (TAB) circuit including a transformer T having a primary coil T1, a first secondary coil T21 and a second secondary coil T22, a primary bridge circuit 111 connected to the primary coil T1, a secondary first bridge circuit 112 connected to the first secondary coil T21, and a secondary second bridge circuit 113 connected to the second secondary 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, 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 are MOSFETs (Metal Oxide Semiconductor Field Effect Transistors). The diodes connected in anti-parallel are freewheel diodes or body diodes, and the capacitors connected in parallel are parasitic capacitances.

[0020] As described above, the AC-DC converter 1 is configured as a triple active bridge circuit. In the first example shown in FIG. 1, the primary side bridge circuit 111 is a three-leg full bridge circuit including a first leg in which two switching elements 11S are connected in series, a second leg in which two switching elements 11S are connected in series, and a third leg in which two capacitors (primary side DC link capacitors: upper side DC link capacitor Cdc1 and lower side DC link capacitor Cdc2) are connected in series. Note that the "leg" may also be referred to as an "arm." The midpoint a of the first leg is connected to one end of the primary side coil T1 via the active bridge inductor Ldab. The midpoint b of the second leg is connected to the other end of the primary side coil T1. The midpoint N of the third leg is a neutral node and is connected to one end (first end, here, negative pole) of an external AC power source. The other end (second end, positive pole here) of the external AC power supply 4 is connected to a midpoint a of the first leg via a first filter inductor Lf1 and is also connected to a midpoint b of the second leg via a second filter inductor Lf2. The first filter inductor Lf1 and the second filter inductor Lf2 are inductors having the same rated inductance. The upper-side DC link capacitor Cdc1 and the lower-side DC link capacitor Cdc2 are capacitors having the same rated capacitance. It can also be said that the primary-side bridge circuit 111 is composed of two half-bridge inverters that share a common capacitive third leg.

[0021] The primary bridge circuit 111 is configured to easily generate a so-called flat-top waveform in which the wave height of a sinusoidal AC waveform is flat, and to have high resistance to changes in input voltage. Therefore, it is suitable for a boost type power converter. In addition, so-called soft switching such as ZVS (Zero Volt Switching) can be easily realized, and circuit loss can be easily reduced.

[0022] The secondary side first bridge circuit 112 and the secondary side second bridge circuit 113 are also configured with full bridge circuits each having two legs with switching elements connected in series. A midpoint c1 of one leg of the secondary side first bridge circuit 112 is connected to one end of the secondary side first coil T21, and a midpoint d1 of the other leg of the secondary side first bridge circuit 112 is connected to the other end of the secondary side first coil T21. A midpoint c2 of one leg of the secondary side second bridge circuit 113 is connected to one end of the secondary side second coil T22, and a midpoint d2 of the other leg of the secondary side second bridge circuit 113 is connected to the other end of the secondary side second coil T22.

[0023] The triple active bridge circuit is controlled by pulse width modulation (PWM) to generate a unity power factor input grid current with minimum total harmonic distortion (THD). In other words, the triple active bridge circuit has a power factor correction (PFC) function and a total harmonic distortion reduction function, and is controlled by pulse width modulation to realize a unity power factor input grid current. The total harmonic distortion is the ratio of the effective value of all harmonics to the fundamental wave of the external AC power source 4. In other words, the total harmonic distortion can be calculated by dividing the sum of the effective values ​​of the harmonic components (second harmonic, third harmonic, etc.) of the fundamental wave (for example, frequencies of 50 [Hz] and 60 [Hz]) of the external AC power source 4 by the effective value of the fundamental wave component.

[0024] The full-bridge power converter is not limited to the form of the first example shown in Fig. 1, and may be configured as in a second example shown in Fig. 2. The primary side bridge circuit 111 of the second example differs from the first example in that the third leg, which is formed by connecting two capacitors (primary side DC link capacitors: upper side DC link capacitor Cdc1 and lower side DC link capacitor Cdc2) in series, is formed by connecting in series a switching element 11S having the same specifications as the first leg and the second leg. The other configurations are the same as those of the first example.

[0025] In the second example, the switching element 11S of the leg to which the filter inductor is connected is switched at a higher speed than the switching element 11S of the leg (third leg) connected to the external AC power supply 4. The switching frequency of the switching element 11S of the third leg having the midpoint N of the neutral node can be reduced to approximately the frequency of the external AC power supply 4. Therefore, the switching elements 11S constituting the first and second legs and the switching element 11S constituting the third leg may be different types of elements depending on the required switching frequency. For example, the first and second legs to which the filter inductor is connected at the midpoint a and the midpoint b are preferably composed of SiC-MOSFET, GaN-MOSFET, or GaN-HEMT (High Electron Mobility Transistor) capable of high-speed switching. The third leg may be composed of Si-MOSFET or IGBT (Insulated Gate Bipolar Transistor) having a lower switching speed than these. Furthermore, the primary side DC link capacitor Cdc is not divided into two capacitors with the neutral node as the midpoint N as in the first example, but is placed as a single capacitor between the positive and negative poles. If the switching frequency of the third leg is set low, a low capacitance of 500μF or less is sufficient for the primary side DC link capacitor Cdc.

[0026] In the embodiment shown in FIG. 1 and FIG. 2, the filter inductor Lf is a parallel divided inductor consisting of a first filter inductor Lf1 and a second filter inductor Lf2 having the same rated inductance. However, the filter inductor Lf may be a single inductor as shown in the modified example of the first example in FIG. 3 and the modified example of the second example in FIG. 4. That is, the primary side bridge circuit 111 may be configured such that the second end of the external AC power source 4 is connected to at least one of the midpoint a of the first leg and the midpoint b of the second leg via the filter inductor Lf. In this embodiment, the second end of the external AC power source 4 is connected to the midpoint b of the second leg via the filter inductor Lf. However, this does not prevent a configuration in which the second end of the external AC power source 4 is connected to the midpoint a of the first leg via the filter inductor Lf depending on the polarity of the active bridge inductor Ldab. The same applies to the third to tenth examples described later with reference to FIG. 5 to FIG. 7 and FIG. 9 to FIG. 13. Although examples such as those shown in Figures 3 and 4 corresponding to the first and second examples are omitted, the filter inductor Lf may be a single inductor rather than a parallel divided inductor consisting of a first filter inductor Lf1 and a second filter inductor Lf2.

[0027] 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 multi-port dual active bridge circuit using a transformer T, i.e., a triple active bridge circuit, so that 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 of a short-circuit fault of the external AC power supply 4 on the vehicle while the first DC power supply 3 and the second DC power supply 30 are being charged.

[0028] The triple active bridge circuit is switched by a control device not shown in Fig. 1 and Fig. 2 through pulse width modulation control. The control device may be, for example, a control device 80 or a vehicle control device 90 described later with reference to Fig. 8. Even if the first stator coil 7 of the first rotating electric machine 7M, the second stator coil 8 of the second rotating electric machine 8M, the first inverter 5, and the second inverter 50 are not used in the on-vehicle charging device 10 as in Figs. 1 and 2, the control device 80 or the vehicle control device 90 shown in Fig. 8 may have the function of a control device that controls the on-vehicle charging device 10. Of course, a control device other than the control device 80 and the vehicle control device 90 may be provided. The control device of the in-vehicle charging device 10 controls the switching of the triple active bridge circuit so as to generate a unity power factor input grid current with a minimum total harmonic distortion, and to generate a first battery voltage (a voltage between the terminals of the first output capacitor Cs1) and a second battery voltage (a voltage between the terminals of the second output capacitor Cs2) with a minimum pulsating component in the first battery current flowing through the first DC power source 3 and the second battery current flowing through the second DC power source 30. The pulsation in the first battery current and the second battery current includes at least the second harmonic component of the grid current of the external AC power source 4. In the first and second examples shown in FIG. 1 and FIG. 2, the current in the first DC power corresponds to the first battery current, and the current in the second DC power corresponds to the second battery current.

[0029] The circuit block diagram of FIG. 5 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 in 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.

[0030] 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.

[0031] 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.

[0032] The first switching circuit 211 has a half-bridge configuration with one leg in which switching elements are connected in series on the upper and lower sides. One end of the first choke coil Le1 is connected to the midpoint of the leg, i.e., the connection point between the upper switching element and the lower switching element. 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.

[0033] Similarly, the second switching circuit 212 has a half-bridge configuration with one leg in which switching elements are connected in series on the upper and lower sides. One end of the second choke coil Le2 is connected to the midpoint of the leg, i.e., the connection point between the upper switching element and the lower switching element. 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.

[0034] The first switching circuit 211 and the second switching circuit 212 are switched and controlled to generate a first battery voltage (a voltage between the terminals of the first output capacitor Cs1) and a second battery voltage (a voltage between the terminals of the second output capacitor Cs2) that minimize the pulsating components in the first battery current flowing through the first DC power source 3 and the second battery current flowing through the second DC power source 30. In many cases, the pulsating components include at least the second harmonic components of the grid current of the external AC power source 4, but the first switching circuit 211 and the second switching circuit 212 reduce the amplitude of the pulsating components. In the configurations (first example and second example) shown in FIG. 1 and FIG. 2, the current in the first DC power corresponds to the first battery current, and the current in the second DC power corresponds to the second battery current. In the third example shown in FIG. 5, the current in the third DC power corresponds to the first battery current, and the current in the fourth DC power corresponds to the second battery current. Similarly, in the fourth, fifth, and sixth examples described later with reference to Figures 6, 7, and 9, the current in the third DC power corresponds to the first battery current, and the current in the fourth DC power corresponds to the second battery current.

[0035] 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.

[0036] The circuit block diagram of FIG. 6 shows a fourth example of the vehicle-mounted charging device 10. The vehicle-mounted charging device 10 of the fourth example is configured to further include a DC-DC converter 2 in addition to the AC-DC converter 1 in the second example. This relationship is similar to the relationship between the first example and the third example, and the third example and the fourth example also have the same configuration of the added DC-DC converter 2 (chopper circuit), so detailed description will be omitted. In the fourth example, by including the DC-DC converter 2, it is possible to further reduce pulsation of the charging voltage (battery voltage) applied from the vehicle-mounted charging device 10 to the first DC power source 3 and the second DC power source 30 and the charging current (battery current) supplied to the first DC power source 3 and the second DC power source 30 compared to the second example.

[0037] Incidentally, electric vehicles and hybrid vehicles, which have become widespread in recent years, are equipped with AC rotating electric machines (traction motors) 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, AC rotating electric machines are 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 coils 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 using 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.

[0038] The circuit block diagram of FIG. 7 is an example of the on-board charging device 10 using the drive control system of the rotating electric machine, and shows a fifth example of the on-board charging device 10. As is clear from a comparison between FIG. 5 and FIG. 7, the first switching circuit 211 constituting the first chopper circuit 21 in the third example of FIG. 5 is configured using a first inverter 5 described later in the fifth example of FIG. 7. Also, the first choke coil Le1 constituting the first chopper circuit 21 in the third example of FIG. 5 is configured using a first stator coil 7 of a first rotating electric machine 7M described later in the fifth example of FIG. 7. The first output capacitor Cs1 is connected to the neutral point 7N of the first stator coil 7. Similarly, the second switching circuit 212 constituting the second chopper circuit 22 is configured using a second inverter 50 described later. Also, the second choke coil Le2 constituting 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 the neutral point 8N of the second stator coil 8.

[0039] As described above, the rotating electric machine mounted on the vehicle is not limited to the 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 above-mentioned first rotating electric machine 7M corresponds to the traction motor. And the second rotating electric machine 8M corresponds to the auxiliary motor.

[0040] Here, the drive control system of the rotating electric machine will be described. The schematic circuit block diagram of Fig. 8 shows an example of the drive control system of the first rotating electric machine 7M. 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 7M, so here, the drive control system of the first rotating electric machine 7M 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.

[0041] 8, the vehicle drive device 9 includes a first rotating electric machine 7M that serves as a drive power 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 7M 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 drive power source, such as an internal combustion engine (not shown), in addition to the first rotating electric machine 7M.

[0042] As shown in FIG. 8, the vehicle drive device 9 includes a control device 80 that controls a first rotating electric machine 7M that is a driving force source for the vehicle, and the control device 80 drives and controls the first rotating electric machine 7M by performing current feedback control. The first rotating electric machine 7M 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 7M may be, for example, provided with two sets of three-phase first stator coils 7 and driven by six-phase AC. The first rotating electric machine 7M can function both as an electric motor and as a generator. When the first rotating electric machine 7M functions as an electric motor, the first rotating electric machine 7M is in a power running state, and when the first rotating electric machine 7M functions as a generator, the first rotating electric machine 7M is in a regenerative state.

[0043] The first inverter 5 is connected to the first AC rotating electric machine 7M and the first DC power source 3, and converts power between multiple phase AC and DC. The first inverter 5 is configured with multiple 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. A pair of DC side terminals of the first inverter 5 are connected to a positive terminal and a negative terminal of the first DC power source 3. In addition, the multiple phase AC side terminals of the first inverter 5 are connected to the multiple phase first stator coils 7, respectively.

[0044] In this embodiment, the first inverter 5 includes a U-phase leg, a V-phase leg, and a W-phase leg as multiple-phase legs. Each leg 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 midpoint of each leg, i.e., the connection point between the upper-stage switching element 5U and the lower-stage switching element 5L, is connected to the corresponding first stator coil 7. Specifically, the midpoint of the U-phase leg is connected to the U-phase coil 7u, the midpoint of the V-phase leg is connected to the V-phase coil 7v, and the midpoint of the W-phase leg is connected to the W-phase coil 7w.

[0045] 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.

[0046] 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 7M 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 7M 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.

[0047] The actual current flowing through the first stator coil 7 of each phase of the first rotating electric machine 7M is detected by a current sensor (motor current sensor 81), and the control device 80 acquires the detection results. In addition, the magnetic pole position (electrical angle) of the rotor of the first rotating electric machine 7M 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 results. 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 (programs).

[0048] As described above, the first rotating electric machine 7M 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 7M by the power of an internal combustion engine or the like to cause the first rotating electric machine 7M 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 7M 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 7M generate electricity. For this reason, it is preferable that the first DC power source 3 be configured to be charged by an external power source when the first DC power source 3 is equipped on the vehicle.

[0049] 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 fourth 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 fifth example, the on-board charging device 10 is configured using a first inverter 5 and a first stator coil 7.

[0050] 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 7M 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 7M 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 7M 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.

[0051] Therefore, in the fifth 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 211 configured using the first inverter 5, a first choke coil Le1 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 212 configured using the second inverter 50, a second choke coil Le2 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.

[0052] The first inverter 5 is configured with one-phase legs 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 legs 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 multi-phase legs are simultaneously and similarly controlled to be turned on and off, and all the lower-stage switching elements 5L of the multi-phase legs are simultaneously and similarly controlled to be turned on and off. Therefore, the first inverter 5 having multiple legs apparently functions as a first switching circuit 211 (see FIG. 5) configured with one leg 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 (see FIG. 5) configured with one leg in which an upper-stage switching element 50U and a lower-stage switching element 50L are connected in series.

[0053] 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 leg 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 leg of the multiple phases is similarly switched and controlled, the first stator coil 7 of each phase has a current flowing between the leg and the neutral point 7N in the same manner, and the second stator coil 8 of each phase has a current flowing between the leg 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 (see FIG. 5) having one end connected to the midpoint of the switching circuit in the chopper circuit and the other end connected to the output capacitor (first output capacitor Cs1). The second stator coil 8 of the multiple phases can also be regarded as one coil, and functions as a second choke coil Le2 (see FIG. 5).

[0054] As shown in FIG. 7, the on-board charging device 10 of the fifth example includes a first main contactor 11, a second main contactor 14, and a grid contactor 13, as well as 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. These contactors are controlled by a control device 80, or the control device 80 and a 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 fourth examples are also controlled by the vehicle control device 90 or a control device (not shown) that controls the on-board charging device 10. As described above with reference to FIG. 8, 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 drive control of the rotating electric machine and charge control by the on-board charging device 10. As is apparent from FIGS. 5 to 8, 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.

[0055] As described above with reference to FIG. 8, the first main contactor 11 is installed so as to be able to make and break an electrical connection between 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 7M 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, as shown in FIG. 7 and other figures, 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.

[0056] 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.

[0057] When the first inverter 5 is used for drive control of the first rotating electric machine 7M, 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 7M 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.

[0058] As shown in FIG. 7, 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] In addition, when 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 as in this embodiment, the second DC power source 30 can be charged by power supplied from the first DC power source 3 or the first rotating electric machine 7M. 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 7M runs by power supplied from the first DC power source 3, or, if the first rotating electric machine 7M is equipped with wheels or an internal combustion engine, generates power by power transmitted from the internal combustion engine and runs regeneratively to supply power to the first DC power source 3.

[0063] 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 is supplied to the second DC power source 30 via the secondary side first bridge circuit 112, the transformer T, and the secondary side second bridge circuit 113.

[0064] 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.

[0065] 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. 7, but even in the vehicle-mounted charging device 10 illustrated in Figs. 1 to 6 that 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 an 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. 7, and therefore detailed description thereof will be omitted.

[0066] 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 may have the same storage capacity. In addition, the first rotating electric machine 7M and the second rotating electric machine 8M may be, for example, both traction motors (such as a two-motor automobile) 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. Of course, it may be possible to switch between a case in which the second DC power source 30 is charged with the power of the first DC power source 3 and a case in which the first DC power source 3 is charged with the power of the second DC power source 30.

[0067] The circuit block diagram of FIG. 9 shows a sixth example of the on-board charging device 10. The on-board charging device 10 of the sixth example is a form in which the drive control system of the rotating electric machine in the fourth example shown in FIG. 6 is used. As is clear from a comparison between FIG. 6 and FIG. 9, the first switching circuit 211 (see FIG. 6) in the first chopper circuit 21 is configured using the first inverter 5. Moreover, the first choke coil Le1 (see FIG. 6) in the first chopper circuit 21 is configured using the first stator coil 7 of the first rotating electric machine 7M. The first output capacitor Cs1 is connected to the neutral point 7N of the first stator coil 7. Similarly, the second switching circuit 212 (see FIG. 6) in the second chopper circuit 22 is configured using the second inverter 50. Moreover, the second choke coil Le2 (see FIG. 6) in the second chopper circuit 22 is configured using the second stator coil 8 of the second rotating electric machine 8M. The second output capacitor Cs2 is connected to the neutral point 8N of the second stator coil 8. As other points are apparent from the above description with reference to FIGS. 1 to 8, detailed description thereof will be omitted.

[0068] As described above, the second DC power source 30 can be charged by power supplied from the first DC power source 3 or the first rotating electric machine 7M, and the first DC power source 3 can be charged by power supplied from the second DC power source 30 or the second rotating electric machine 8M. Therefore, the vehicle-mounted charging device 10 does not need to include a DC-DC converter 2 (chopper circuit) in both of the multi-port outputs, and may include a DC-DC converter 2 in only one of them. That is, the third example shown in FIG. 5 may be configured as the seventh example shown in FIG. 10, and the fourth example shown in FIG. 6 may be configured as the eighth example shown in FIG. 11. In addition, the fifth example shown in FIG. 7 may be configured as the ninth example shown in FIG. 12, and the sixth example shown in FIG. 9 may be configured as the tenth example shown in FIG. 13.

[0069] Here, the characteristics of the seventh to tenth examples will be described with the seventh example as a representative example. The in-vehicle charging device 10 of the seventh example shown in FIG. 10 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 in-vehicle 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, the first DC link capacitor 6 is arranged as in the third example. It can be said that the in-vehicle charging device 10 of the seventh example is configured without including the second chopper circuit 22 in relation to the in-vehicle charging device 10 of the third example. The in-vehicle charging device 10 of the seventh 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.

[0070] 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.

[0071] The on-board charging device 10 of the seventh to tenth examples shown in Fig. 10 to Fig. 13 is configured such that 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, it may be configured such that 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.

[0072] That is, the in-vehicle charging device 10 of the seventh to tenth examples 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 and second examples, 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 and second examples, the second DC link capacitor 60 is arranged as in the third and fourth examples. It can be said that the in-vehicle charging device 10 of the seventh to tenth examples is configured without including the first chopper circuit 21 in relation to the third to sixth examples. 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.

[0073] In this way, the on-vehicle charging device 10 of the seventh to tenth examples 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 to the third DC power or converts the second DC power to the fourth DC power. When the chopper circuit (the first chopper circuit 21) converts the first DC power to 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.

[0074] The switching circuit (the first switching circuit 211 or the second switching circuit 212) is switched and controlled so as to generate a first battery voltage (a voltage between the terminals of the first output capacitor Cs1) and a second battery voltage (a voltage between the terminals of the second output capacitor Cs2) that minimizes the pulsating components in the first battery current flowing through the first DC power source 3 and the second battery current flowing through the second DC power source 30. In many cases, the pulsating components include at least the second harmonic components of the grid current of the external AC power source 4, but the amplitude of the pulsating components is further reduced by one switching circuit connected to one of the secondary bridge circuits of the AC-DC converter 1. In the seventh to tenth examples shown in FIGS. 10 to 13 in which the chopper circuit is the first chopper circuit 21, the current in the third DC power corresponds to the first battery current, and the current in the second DC power corresponds to the second battery current. When the chopper circuit is the second chopper circuit 22, the current in the first DC power corresponds to the first battery current, and the current in the fourth DC power corresponds to the second battery current.

[0075] 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 second coil T22 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.

[0076] Similarly to the relationship between the third and fourth examples and the fifth and sixth examples, in the seventh and eighth examples, as in the on-board charging devices 10 of the ninth and tenth examples illustrated in Figs. 12 and 13, for example, the stator coil of the rotating electric machine and the 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 7M 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).

[0077] 12 and 13 show a ninth example and a tenth example of the in-vehicle 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 7M having the first stator coils 7 of the multiple phases connected to each other at the neutral point 7N via the first inverter 5 that converts 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 the multiple phases, and the first output capacitor Cs1 connected to the neutral point 7N of the first stator coils 7 of the multiple phases. Details of the function switching method and the like are as described above, so detailed description will be omitted.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] The in-vehicle charging device (10) according to this embodiment will be briefly summarized below.

[0084] In one embodiment, an in-vehicle charging device (10) charges a first DC power source (3) and a second DC power source (30) electrically insulated from the first DC power source (3) with power supplied from an external AC power source (4), and includes an AC-DC converter (1) that converts power between AC power on the side of the external AC power source (4) and a first DC power on the side of the 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 the second DC power source (30), and the AC-DC converter (1) ) is a triple active bridge 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), and the primary bridge circuit (111) includes a first leg in which two switching elements (11S) are connected in series, The inverter circuit includes a second leg in which two switching elements (11S) are connected in series, and a third leg which is a leg in which two switching elements (11S) are connected in series or a leg in which two capacitors are connected in series, and a midpoint (a) of the first leg is connected to one end side of the primary coil (T1), a midpoint (b) of the second leg is connected to the other end side of the primary coil (T1), a midpoint (N) of the third leg is connected to a first end which is one end side of the external AC power supply (4), and a second end which is the other end side of the external AC power supply (4) is connected to a fuse. The triple active bridge circuit is configured as a full-bridge power converter connected to at least one of the midpoint (N) of the first leg and the midpoint (N) of the second leg via a filter inductor (Lf), and the triple active bridge circuit is switching controlled to generate a unity power factor input grid current with minimal total harmonic distortion, and to generate a first battery voltage and a second battery voltage with minimal pulsating components in a first battery current flowing in the first DC power source (3) and a second battery current flowing in the second DC power source (30).

[0085] According to this configuration, since the AC-DC converter (1) is configured with the transformer (T), it is possible to ensure insulation 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). In this state where insulation is ensured, the first DC power source (3) and the second DC power source (30) are charged with the first DC power and the second DC power converted by the AC-DC converter (1) without providing a separate converter for converting power between DC and DC, so that the in-vehicle charging device (10) can be configured on a small scale. Therefore, according to this configuration, it is possible to suppress the system cost of the in-vehicle charging device (10) that charges the in-vehicle DC power sources (3, 30) with power from the external AC power source (4).

[0086] Furthermore, it is preferable that the filter inductor (Lf) of the in-vehicle charging device (10) includes a first filter inductor (Lf1) and a second filter inductor (Lf2) connected in parallel to the second end of the external AC power supply (4), and the second end of the external AC power supply (4) is connected to a midpoint (N) of the first leg via the first filter inductor (Lf1) and is connected to a midpoint (N) of the second leg via the second filter inductor (Lf2).

[0087] According to this configuration, by connecting the filter inductors (Lf) in parallel, the filter effect can be enhanced, and the noise superimposed on the first DC power and the second DC power can be further suppressed.

[0088] It is preferable that the on-board charging device (10) includes a first chopper circuit (21) having a first switching circuit (211), a first choke coil (Le1), and a first output capacitor (Cs1) and converting the first DC power into a third DC power, and a second chopper circuit (22) having a second switching circuit (212), a second choke coil (Le2), and a second output capacitor (Cs2) and converting the second DC power into a fourth DC power, wherein the first DC power source (3) is charged with the third DC power and the second DC power source (30) is charged with the fourth DC power, and the first switching circuit (211) and the second switching circuit (212) are switched and controlled to generate the first battery voltage and the second battery voltage such that pulsating components in the first battery current and the second battery current are minimized.

[0089] According to this configuration, even if pulsation of harmonic components of the frequency of the external AC power supply (4) remains 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).

[0090] In addition, when the in-vehicle charging device (10) includes the first chopper circuit (21) and the second chopper circuit (22), the first DC power source (3) is connected to a first rotating electric machine (7M) including first stator coils (7) of multiple phases connected to each other at a neutral point (7N) via a first inverter (5) that converts power between DC and AC, and the second DC power source (30) is connected to a second rotating electric machine (8M) including second stator coils (8) of multiple phases connected to each other at a neutral point (8N) via a second inverter (50) that converts power between DC and AC, and the first chopper circuit (21) is configured using the first inverter (5). It is preferable that the second chopper circuit (22) is configured to include the second switching circuit (212) configured using the second inverter (50), the second choke coil (Le2) configured using the second stator coil (8) of multiple phases, and the second output capacitor (Cs2) connected to the neutral point (8N) of the second stator coil (8) of multiple phases.

[0091] According to this configuration, the DC power supply (3, 30) connected to the rotating electric machine (7M, 8M) can be charged by using a stator coil (7, 8) provided in the rotating electric machine (7M, 8M) and an inverter (5, 50) that drives and controls the rotating electric machine (7M, 8M). By using a combined inverter (5, 50) and stator coil (7, 8), the in-vehicle charging device (10) can be configured to be small in size.

[0092] The vehicle-mounted charging device (10) includes a switching circuit (211 or 212), a choke coil (Le1 or Le2), and an output capacitor (Cs1 or Cs2), and includes a chopper circuit (21 or 22) that converts the first DC power into a third DC power or converts the second DC power into a fourth DC power. When the chopper circuit is a circuit (21) that 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 fourth DC power. with the second DC power, and in the case where the chopper circuit is a circuit (22) that converts the second DC power into the fourth DC power, it is preferable that 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, and the switching circuit (211 or 212) is switching controlled to generate the first battery voltage and the second battery voltage such that pulsating components in the first battery current and the second battery current are minimized.

[0093] When the chopper circuit (21) is provided 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 chopper circuit (21) connected to the secondary first coil (T21) is suppressed, so that the pulsation of the second DC power appearing in the secondary second coil (T22) electromagnetically coupled to the primary coil (T1) is also suppressed. Similarly, when the chopper circuit (22) is provided 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 second coil (T22) 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, whereby the pulsation of the 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 chopper circuits (21, 22) 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 supplied to both the first DC power source (3) and the second DC power source (30) can be appropriately suppressed.

[0094] In addition, when the on-board charging device (10) includes the chopper circuit (21 or 22), it is preferable that the DC power source (3 or 30) of the first DC power source (3) and the second DC power source (30), which is charged via the chopper circuit (21 or 22), is connected to a rotating electric machine (7M or 8M) including multiple-phase stator coils (7 or 8) connected to each other at a neutral point (7N or 8N) via an inverter (5 or 50) that converts power between DC and AC, and the chopper circuit (21 or 22) is configured to include the switching circuit (211 or 212) configured using the inverter (5 or 50), the choke coil (Le1 or Le2) configured using the multiple-phase stator coils (7 or 8), and the output capacitor (Cs) connected to the neutral point (7N or 8N) of the multiple-phase stator coils (7 or 8).

[0095] According to this configuration, the inverter (5 or 50) and the stator coil (7 or 8) are combined, so that the in-vehicle charging device (10) can be configured to be small in size. [Explanation of symbols]

[0096] 1: AC-DC converter, 3: first DC power source, 4: external AC power source, 5: first inverter, 5S: switching element, 7: first stator coil, 7M: first rotating electric machine, 7N: neutral point, 8: second stator coil, 8M: second rotating electric machine, 8N: neutral point, 10: on-board charging device, 11S: switching element, 12S: switching element, 13S: switching element, 21: first chopper circuit, 21S: switching element, 22: second chopper circuit, 22S: switching element, 30: second DC power source, 50: second inverter, 111: primary side bridge circuit, 112: secondary side first bridge circuit, 113: secondary side second bridge circuit, 211: first switching circuit, 212: second chopper circuit, switching circuit, Cdc1: upper DC link capacitor (capacitor connected in series to the third leg), Cdc2: lower DC link capacitor (capacitor connected in series to the third leg), Cs: output capacitor, Cs1: first output capacitor, Cs2: second output capacitor, Ldab: inductor, Le1: first choke coil, Le2: second choke coil, Lf: filter inductor, Lf1: first filter inductor, Lf2: second filter inductor, N: midpoint (midpoint of the third leg), T: transformer, T1: primary coil, T21: first secondary coil, T22: second secondary coil, a: midpoint (midpoint of the first leg), b: midpoint (midpoint of the first leg)

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, The primary side bridge circuit includes: a first leg in which two switching elements are connected in series; a second leg in which two switching elements are connected in series; a third leg, the third leg being a leg in which two switching elements are connected in series or a leg in which two capacitors are connected in series; The midpoint of the first leg is connected to one end of the primary coil, The midpoint of the second leg is connected to the other end of the primary coil, a midpoint of the third leg is connected to a first end which is one end side of the external AC power source; a second end of the external AC power supply is connected to at least one of a midpoint of the first leg and a midpoint of the second leg via a filter inductor, The triple active bridge circuit comprises: Producing unity power factor input grid current with minimal total harmonic distortion while an on-board charging device that is switching controlled to generate a first battery voltage and a second battery voltage that minimize the pulsating components in a first battery current flowing through the first DC power supply and a second battery current flowing through the second DC power supply.

2. the filter inductor includes a first filter inductor and a second filter inductor connected in parallel to the second end of the external AC power supply; 2. The on-board charging device according to claim 1, wherein the second end of the external AC power supply is connected to a midpoint of the first leg via the first filter inductor and is connected to a midpoint of the second leg via the second filter inductor.

3. 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; charging the second DC power source with the fourth DC power; 3. The in-vehicle charging device according to claim 1, wherein the first switching circuit and the second switching circuit are switching-controlled to generate the first battery voltage and the second battery voltage such that pulsating components in the first battery current and the second battery current are minimized.

4. 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 in-vehicle charging device according to claim 3 , further comprising: the second output capacitor connected to a neutral point of the second stator coil of a plurality of phases.

5. 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; charging the second DC power source with the fourth DC power; 3. The on-board charging device according to claim 1, wherein the switching circuit is switched and controlled to generate the first battery voltage and the second battery voltage such that pulsating components in the first battery current and the second battery current are minimized.

6. 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 5 , further comprising: the output capacitor connected to a neutral point of the stator coils of a plurality of phases.

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