Vehicle-mounted charging device

Abstract

The vehicle-mounted charging device is configured so as to suppress an increase in system cost, and the vehicle-mounted charging device charges the DC power source of a vehicle drive device provided with the rotating electrical machine, the inverter, and the DC power source by means of power from an external AC power source using the coil of the rotating electrical machine and the inverter. A vehicle-mounted charging device for charging a DC power source of a vehicle drive device provided with a winding excitation type rotating electric machine, an inverter, an excitation circuit, and the DC power source by means of power supplied from an external AC power source, the vehicle-mounted charging device being provided with: a first circuit including the excitation circuit; the power conversion unit converts power between the AC power on the side of the external AC power supply and the first DC power. And a second circuit configured to include an inverter, a multi-phase stator coil, and an output capacitor connected between a neutral point of the stator coil and a negative electrode of the direct current, the second circuit generating second direct current power from the first direct current power to charge the direct current power source.

Description

Technical Field

[0001] The invention relates to a vehicle-mounted charging device. Background Art

[0002] Japanese Patent Publication No. 2022-503713 discloses an onboard charging device (onboard charger, Onboardcharger), which charges a DC power source mounted on a vehicle such as an electric vehicle or a hybrid vehicle that has a rotating electric machine as a driving force source for the wheels while being mounted on the vehicle (the reference numerals in parentheses in the background art are reference numerals of the referenced document). Figure 3 An on-vehicle charging device is illustrated in the figure, wherein a single-phase external AC power source (310) is connected to the neutral point of a three-phase coil connected in a Y shape, each arm of the AC side of an inverter (220) is connected to each of the three-phase coils, an input side terminal of a DC converter (DC / DC converter) is connected to the DC side terminal of the inverter (220), and a DC power source is connected to the output side terminal of the DC converter. The three-phase coil and the inverter (220) form an AC / DC converter (AC / DC converter) that converts a sinusoidal grid current from the external AC power source (310) into a DC power source. By switching the inverter (220), the AC / DC converter also functions as a power factor correction (PFC) circuit that corrects the power factor of the DC power converted from the AC power. The current after the AC / DC conversion generates a ripple with a frequency twice the frequency (system frequency) of the external AC power source (310). The DC converter reduces the ripple and generates a battery current for charging the DC power source.

[0003] Patent Document 1: Japanese Patent Application No. 2022-503713

[0004] Here, for example, in an on-board charger of an electric vehicle or a hybrid vehicle, as a three-phase coil, a coil (stator coil) provided in the stator of a rotating electric machine that is a driving force source of the vehicle can be used. However, such a rotating electric machine is designed to have a high power density and a small inductance. Figure 3 As exemplified in FIG. 1 , when an AC-DC converter is formed by connecting a single-phase external AC power supply to a neutral point, the peak value of the harmonic current of the system current of the external AC power supply tends to increase during AC-DC conversion.

[0005] As a method for suppressing this situation, it is possible to consider increasing the control frequency of the inverter constituting the AC-DC converter. Alternatively, in order to reduce the ripple on the DC converter side, it is possible to consider increasing the control frequency of the DC converter. Among them, when the control frequency is increased, it is also necessary to shorten the control cycle (operation frequency) of the control device that controls the inverter and the DC converter. In addition, the switching action at a high frequency accompanied by a fast control cycle increases the loss of the switching elements possessed by the inverter and the DC converter, causing a decrease in the efficiency of the on-board charging device. In addition, as a control device, it is necessary to use a microcomputer capable of high-speed operation, etc., which causes an increase in the cost of the on-board charging device. Alternatively, as another method, it is also considered to add an inductor between the external AC power supply and the neutral point of the multi-phase coil. However, in this case, the cost of the on-board charging device is also increased due to the addition of the inductor. Summary of the invention

[0006] In view of the above, it is desired to construct a vehicle-mounted charging device in a manner that suppresses an increase in system cost, wherein the vehicle-mounted charging device charges a vehicle drive device having a rotating motor, an inverter, and a DC power supply using power from an external AC power supply, and the DC power supply uses the coil of the rotating motor and the inverter to charge the DC power supply.

[0007] In view of the above-mentioned on-vehicle charging device charging the DC power supply of the vehicle drive device by the power supplied from the external AC power supply, the vehicle drive device comprises: a winding-excited rotating electric machine, which has a stator with multi-phase stator coils connected to each other at a neutral point and a rotor with an exciting winding for generating an exciting magnetic flux, and serves as a driving force source for the wheels; the DC power supply; an inverter connected between the stator coil and the DC power supply and converting power between DC and multi-phase AC; and an excitation circuit connected to the exciting coil. The vehicle-mounted charging device is connected between the magnetic winding and the above-mentioned DC power supply and excites the above-mentioned excitation winding. The vehicle-mounted charging device comprises: a first circuit, which is composed of the above-mentioned excitation circuit and converts power between the AC power on the side of the above-mentioned external AC power supply and the first DC power; and a second circuit, which is composed of the above-mentioned inverter, the multi-phase stator coil and the output capacitor, and generates the second DC power for charging the above-mentioned DC power supply from the above-mentioned first DC power, and the above-mentioned output capacitor is connected between the above-mentioned neutral point of the above-mentioned stator coil and the negative pole of the DC.

[0008] According to the present structure, the first circuit is formed using an excitation circuit, and the first circuit is formed using an inverter and a stator coil. Therefore, compared with the case where a circuit for charging a DC power supply is separately provided, a vehicle-mounted charging device can be formed by simplifying the structure. In addition, a suitable inductance is sought for the circuit that converts power between the AC power on the side of the external AC power supply and the first DC power in the circuit constituting the vehicle-mounted charging device. The coil of the rotating motor can be used as an inductor, but the rotating motor is designed to have a high power density, and the inductance of the coil is usually small. According to the present structure, the first circuit that requires a suitable inductance for converting power between the AC power and the first DC power is formed without using the coil of the rotating motor. Therefore, the first circuit can be formed while ensuring sufficient AC-DC conversion performance such as a power factor correction function. In addition, by using the drive system circuit of the rotating motor to form the second circuit that does not require a higher inductance, the cost of the vehicle-mounted charging device can be reduced. Furthermore, it is possible to set a suitable inductance for the AC-DC converter, so that even if the first circuit is a switching power supply circuit, it is not necessary to control the first circuit with a shorter control period (higher control frequency), and the loss of the switching element constituting the first circuit is also easily reduced. Thus, according to this structure, it is possible to configure a vehicle-mounted charging device in a manner that suppresses an increase in system cost, and the vehicle-mounted charging device uses the coil of the rotating electric machine and the inverter to charge the DC power supply of a vehicle drive device having a rotating electric machine, an inverter, and a DC power supply with power from an external AC power supply.

[0009] Further features and advantages of the vehicle-mounted charging device will become apparent from the following description of exemplary and non-limiting embodiments described with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic circuit block diagram of a drive control system of a rotating electrical machine.

[0011] Figure 2 This is a circuit block diagram showing a first example of the vehicle-mounted charging device.

[0012] Figure 3 This is a circuit block diagram showing a second example of the on-vehicle charging device.

[0013] Figure 4 This is a circuit block diagram showing a third example of the vehicle-mounted charging device.

[0014] Figure 5 This is a circuit block diagram showing a fourth example of the vehicle-mounted charging device.

[0015] Figure 6 Yes Figure 4 and Figure 5 The functional block diagram of the circuit block diagram shown is deformed.

[0016] Figure 7 1 is a circuit block diagram showing a comparative example of an in-vehicle charging device.

[0017] Description of Reference Numerals

[0018] 1...1st circuit; 2...2nd circuit; 3...DC power supply; 4...external AC power supply; 5...inverter; 7...coil (stator coil); 7N...neutral point; 9...vehicle drive device; 10...on-board charger; 11...main contactor (1st contactor); 12...OBC contactor (2nd contactor); 14...excitation contactor (3rd contactor); 50...excitation circuit; 70...rotating electric machine; Cs...output capacitor; T1d...DC side terminal; T5d...DC side terminal. DETAILED DESCRIPTION

[0019] Hereinafter, embodiments of the vehicle-mounted charging device will be described with reference to the drawings. Figure 1 The circuit block diagram schematically shows the drive control system of the rotating electrical machine 70. Figures 2 to 5 The circuit block diagram of FIG. 1 shows an example of an on-vehicle charging device 10 using a drive control system of a rotating electric machine 70. The on-vehicle charging device 10 is a device mounted on a vehicle and used to charge a rotating electric machine 70. Figure 1 A device for charging the DC power supply 3 provided in the vehicle drive device 9 as shown. Figure 1 As shown, the vehicle drive device 9 of this embodiment includes: a rotating electric machine 70 that becomes a driving force source for wheels of a hybrid vehicle, an electric vehicle, etc., an inverter 5 that converts power between direct current and multi-phase alternating current (here, three phases), and a direct current power source 3 connected to the inverter 5. In addition, the vehicle drive device 9 may also include other driving force sources such as an internal combustion engine (not shown) in addition to the rotating electric machine 70.

[0020] like Figures 2 to 5 As shown, the onboard charging device 10 is a device that charges the DC power supply 3 of the vehicle drive device 9 with power supplied from the external AC power supply 4 (grid power supply, single-phase here), and is a so-called onboard charger. In this embodiment, the onboard charging device 10 is configured to be partially shared with the vehicle drive device 9. Specifically, the inverter 5, the coil 7 (stator coil) of the rotating motor 70, and the excitation circuit 50 are shared.

[0021] like Figure 1As shown, the vehicle drive device 9 includes a control device 8, and the control device 8 controls the rotating electric machine 70 that is the driving force source of the vehicle as a control object, and the control device 8 drives and controls the rotating electric machine 70 by performing current feedback control. The rotating electric machine 70 to be driven is a stator 71 having a stator core with a multi-phase (N is an arbitrary natural number, N phases, and in this embodiment, a three-phase form of N=3 is exemplified) coil 7 (stator coil) and a winding excitation type rotor 72 (EESM: Electrically Excited Synchronous Motor). The winding excitation type synchronous rotating electric machine has a rotor structure in which an electromagnet having an excitation winding 7r is used as an excitation source instead of a permanent magnet. The excitation magnetic flux generated by the electromagnet can be adjusted by the excitation current supplied to the excitation winding 7r from the excitation circuit 50 controlled by the control device 8. The excitation circuit 50 is configured with a switching element, and adjusts (transforms) the DC voltage supplied from the DC power supply 3 and applies it to the excitation winding 7r. Compared with the permanent magnet type rotating machine (PMSM: Permanent Magnet Synchronous Motor), the winding excitation type synchronous rotating machine has the advantages of (1) the efficiency in the medium-high speed and low torque operation area is expected to be improved due to the variable excitation magnetic flux, and the constant output range can be expanded, and (2) it is not affected by the unstable supply of permanent magnets using rare earths, etc. Therefore, in recent years, the use of the winding excitation type synchronous rotating machine as a driving force source for wheels in electric vehicles and hybrid vehicles has also been expanding.

[0022] As described above, the winding-excitation type synchronous rotating electric machine excites the rotor 72 by passing an excitation current through the excitation winding 7r of the rotor 72. However, since the rotor 72 rotates, a structure is required to pass an excitation current in the same direction through the excitation winding 7r. Figure 1 The structure with brush 73 as a mechanical switching structure is exemplified in FIG. Figure 2 and Figure 4 The rotating motor 70 is also provided with a brush 73. Figure 3 and Figure 5 The drive circuit 74 is provided in place of the brush 73 to electrically change the direction of the exciting current like the rotating electric machine 70 of the present invention (brushless EESM). The drive circuit 74 is provided with, for example, a rotary transformer 75 and a rectifier circuit 76. The structure of such a winding-excitation type synchronous rotating electric machine is well known, and therefore, a detailed description thereof is omitted.

[0023] In the present embodiment, the stator 71 is exemplified as a Y-type (star) form in which the three-phase coils 7 are short-circuited at the neutral point 7N. However, the rotating electric machine 70 may also be a form in which it is provided with two sets of, for example, three-phase coils 7 and is driven by a six-phase alternating current. In addition, the rotating electric machine 70 can function as a motor and can also function as a generator. When the rotating electric machine 70 functions as a motor, the rotating electric machine 70 is in a power running state, and when the rotating electric machine 70 functions as a generator, the rotating electric machine 70 is in a regeneration state.

[0024] like Figure 1 As shown, the vehicle drive device 9 includes an inverter 5. The inverter 5 is connected to the AC rotating electric machine 70 and the DC power supply 3, and converts power between multi-phase AC and DC. A pair of DC side terminals (DC side terminals T5d) of the inverter 5 are connected to the positive and negative terminals of the DC power supply 3. Specifically, the terminal on the positive side of the pair of DC side terminals T5d (inverter positive terminal T5P) is connected to the positive pole of the DC power supply 3, and the terminal on the negative side of the pair of DC side terminals T5d (inverter negative terminal T5N) is connected to the negative pole of the DC power supply 3. In addition, the multi-phase AC side terminals of the inverter 5 are respectively connected to the multi-phase coils 7. In the present embodiment, the inverter 5 includes a U-phase arm, a V-phase arm, and a W-phase arm as multi-phase arms. Each arm is formed by connecting the upper switching element 5U arranged on the positive side and the lower switching element 5L arranged on the negative side in series. The midpoint of each arm, i.e., the connection point between the upper switching element 5U and the lower switching element 5L, is connected to each coil 7. Specifically, the midpoint of the U-phase arm is connected to the U-phase coil 7u, the midpoint of the V-phase arm is connected to the V-phase coil 7v, and the midpoint of the W-phase arm is connected to the W-phase coil 7w.

[0025] The DC side of the inverter 5 includes a smoothing capacitor (DC link capacitor 6) for smoothing the voltage between the positive and negative electrodes (DC link voltage Vdc). The DC side of the inverter 5 also includes a voltage sensor (DC link voltage sensor 61) for detecting the DC link voltage Vdc.

[0026] The DC power supply 3 is composed of, for example, a rechargeable secondary battery (battery) such as a lithium-ion battery, an electric double-layer capacitor, or the like. As in the present embodiment, when the rotating motor 70 is the driving force source of the vehicle, the DC power supply 3 is a high-voltage and large-capacity DC power supply, and the rated power supply voltage is, for example, 200 to 400 [V]. In most cases, the DC power supply 3 is configured so that it can be electrically connected and disconnected with respect to the inverter 5 and the rotating motor 70 by operating the main switch (ignition switch) of the vehicle, etc. For example, the DC power supply 3 is connected to the inverter 5 and the rotating motor 70 via a main contactor 11 (first contactor) composed of a relay, etc. In addition, the DC power supply 3 also has a function of detecting the input and output current (battery current Ibat: refer to Figure 6 ) of the current sensor (battery current sensor 31), detecting the terminal voltage of the DC power supply 3 (battery voltage Vbat: refer to Figure 6 ) voltage sensor (battery voltage sensor 32).

[0027] Although not shown in the figure, in the case where the DC power source 3 is a lithium-ion battery, for example, a battery management system (BMS) is usually provided. Secondary batteries such as lithium-ion batteries are composed of a plurality of cells (battery cells). The battery management system is a management and control system for the battery that performs the following processes: (1) prevention of overcharging and overdischarging of cells; (2) prevention of overcurrent flowing into cells; (3) temperature management of cells; (4) calculation of the state of charge (SOC); (5) equalization of cell voltages; etc. The above-mentioned battery current sensor 31 and battery voltage sensor 32 may also constitute part of the battery management system.

[0028] like Figure 1 As shown, the inverter 5 is configured to have a plurality of switching elements 5S. It is preferred that the switching element 5S use power semiconductor elements such as IGBT (Insulated Gate Bipolar Transistor), Power-MOSFET (Metal Oxide Semiconductor Field Effect Transistor), SiC-MOSFET (Silicon Carbide-Metal Oxide Semiconductor FET), SiC-SIT (SiC-Static Induction Transistor), GaN-MOSFET (Gallium Nitride-MOSFET) that can operate at high frequency. In the present embodiment, the form of using FET is exemplified as the switching element 5S. In addition, in the present embodiment, in each switching element 5S, a freewheeling diode is connected in parallel with the direction from the negative electrode toward the positive electrode (the direction from the lower side toward the upper side) as the forward direction. Of course, it is also possible that in the case of using a body diode, in the case of reverse conduction of a transistor of a wide bandgap semiconductor composed of enhancement mode gallium nitride (E-GaN), etc., such a freewheeling diode is not provided.

[0029] like Figure 1As shown, the inverter 5 is controlled by the control device 8. The control device 8 is constructed with a logic circuit such as a microcomputer as a core component. For example, the control device 8 performs current feedback control using a vector control method based on the target torque (torque command) of the rotating motor 70 provided as a request signal from other control devices such as the vehicle control device 90 as one of the upper control devices, and drives the rotating motor 70 via the inverter 5. In the vector control method, the current flowing to the coil 7 of each phase (in this embodiment, the U-phase current Iu, the V-phase current Iv, and the W-phase current Iw: refer to Figure 6 Feedback control is performed by transforming the coordinates of the direction of the magnetic field generated by the rotor 72, i.e., the d-axis and the q-axis in the direction orthogonal to the d-axis (the direction in which the electrical angle advances by π / 2 relative to the direction of the magnetic field) into a vector component of the q-axis. The coordinate system of the coordinate transformation target is called the dq-axis orthogonal coordinate system. In addition, the operating voltage of logic circuit elements such as microcomputers is about 3.3 to 5 volts. In this embodiment, for simplicity, the illustration is omitted, but the control signal generated by the logic circuit element is transmitted to the inverter 5 via the drive circuit. Alternatively, it can also be considered that the control device 8 includes a drive circuit.

[0030] The actual current flowing in the coil 7 of each phase of the rotating motor 70 is detected by the current sensor (motor current sensor 81), and the control device 8 obtains the detection result. In addition, the rotational position of the rotor 72 of the rotating motor 70 at each moment and the rotational speed (angular velocity) of the rotor are detected by a rotation sensor 82 such as a rotary transformer and an inductive position sensor (Inductive Position Sensor), and the control device 8 obtains the detection result. The control device 8 performs current feedback control using the detection results of the motor current sensor 81 and the rotation sensor 82. The control device 8 is configured to have various functional units for current feedback control, and each functional unit is implemented by the cooperative action between hardware such as a microcomputer and software (program).

[0031] As described above, the rotating electric machine 70 connected to the DC power source 3 via the inverter 5 functions as a motor due to the power supplied from the DC power source 3, and can also function as a generator to charge the DC power source 3. For example, in a hybrid vehicle, it is also possible to supply mechanical energy to the rotating electric machine 70 by the power of an internal combustion engine, etc., so that the rotating electric machine 70 generates electricity, but sometimes there are few opportunities for power generation and the DC power source 3 cannot be fully charged. In addition, for an electric vehicle that only carries the rotating electric machine 70 as a driving force source, it is limited to power generation by mechanical energy from the wheels in the case of inertial driving, etc., and there are many cases where the DC power source 3 cannot be fully charged. In addition, in a hybrid vehicle, it is also possible that the energy efficiency is higher when power is supplied from the outside than when the rotating electric machine 70 generates electricity. Therefore, it is preferably configured so that the DC power source 3 can be charged by an external power source when the DC power source 3 is mounted on the vehicle.

[0032] The vehicle-mounted charging device 10 of this embodiment charges the DC power supply 3 of the vehicle drive device 9 with the power supplied from the external AC power supply 4. Figures 2 to 5 As shown, the vehicle-mounted charging device 10 includes: a first circuit 1 connected to an external AC power source 4 and converting AC power from the external AC power source 4 into a first DC power; and a second circuit 2 generating a second DC power for charging the DC power source 3 from the first DC power. The first circuit 1 is composed of an excitation circuit 50. The second circuit 2 is composed of an inverter 5, a multi-phase coil 7 and an output capacitor Cs. The output capacitor Cs is connected between the neutral point 7N of the coil 7 and the negative pole of the DC. As described later, the first circuit 1 is an AC-to-DC converter (AC / DC converter), and the second circuit 2 is a DC-to-AC converter (DC / AC converter) or an active decoupling circuit.

[0033] The first circuit 1 (AC-DC converter) and the second circuit 2 (DC converter or active decoupling circuit) are composed of switching elements (switching elements shown by reference numerals 1S and 5S), and these switching elements are controlled by the control device 8 that drives and controls the rotating electric machine 70 via the inverter 5. In addition, as described later, the vehicle-mounted charging device 10 is composed of contactors (main contactor 11, OBC contactor 12 (second contactor), grid contactor 13, excitation contactor 14 (third contactor)). These contactors are composed of relays, for example, and these contactors are also controlled by the control device 8 or by the control device 8 and the vehicle control device 90. As shown in FIG. Figure 1 As described above, the control device 8 is included in the drive control system of the rotating electrical machine, and the control device 8 is also commonly used in the drive control of the rotating electrical machine 70 and the charge control of the DC power source 3 .

[0034] When charging the DC power supply 3, power is supplied from the external AC power supply 4 to the DC power supply 3. Therefore, in terms of circuit structure, the first circuit 1 (AC-DC converter) arranged on the side (upstream side) of the external AC power supply 4 may be referred to as a front-end circuit, and the second circuit 2 (DC converter or active decoupling circuit) arranged on the side (downstream side) of the DC power supply 3 may be referred to as a back-end circuit. In the present embodiment, the front-end circuit connected to the external AC power supply 4, i.e., the first circuit 1 (AC-DC converter) and the back-end circuit arranged closer to the DC power supply 3 than the first circuit 1, i.e., the second circuit 2 (DC converter or active decoupling circuit) are configured as a driving system circuit (excitation circuit 50, coil 7 and inverter 5) of the common rotating electric machine 70. In addition, in the present embodiment, AC power is supplied from the external AC power supply 4 to the vehicle-mounted charging device 10 via an EMI filter FLT that reduces EMI (Electro Magnetic Interference) noise.

[0035] Hereinafter, a specific circuit configuration will be described by way of example. Figure 2 and Figure 3 The second circuit 2 is exemplified as a vehicle-mounted charging device 10 in the form of a DC converter. Figure 4 and Figure 5 The in-vehicle charging device 10 is exemplified in which the second circuit 2 is an active decoupling circuit. Figure 2 A first example of the vehicle-mounted charging device 10 is shown. Figure 3 A second example of the vehicle-mounted charging device 10 is shown. Figure 4 A third example of the vehicle-mounted charging device 10 is shown. Figure 5 A fourth example of the vehicle-mounted charging device 10 is shown. Figure 2 and Figure 4 As an example, the excitation current is switched mechanically by means of brush 73. Figure 3 and Figure 5 This example shows a mode in which the excitation current is switched in an electrical structure by the drive circuit 74.

[0036] like Figure 2 and Figure 3As shown, the on-vehicle charging device 10 includes a main contactor 11, an OBC contactor 12, a grid contactor 13, and an excitation contactor 14. The main contactor 11 disconnects and connects the electrical connection between the output capacitor Cs and the DC power supply 3, and disconnects and connects the electrical connection between the DC power supply 3 and the DC side terminal T5d of the inverter 5 and the electrical connection between the DC power supply 3 and the excitation circuit 50 in a complementary manner to the output capacitor Cs. The OBC contactor 12 disconnects and connects the electrical connection between the neutral point 7N and the output capacitor Cs. The grid contactor 13 selectively connects the AC side terminal T1a of the first circuit 1 (AC / DC converter) to the external AC power supply 4 (disconnects and connects the AC side terminal T1a to the external AC power supply 4). The excitation contactor 14 disconnects and connects the electrical connection between the excitation circuit 50 and the excitation winding 7r.

[0037] When the grid contactor 13 is closed, the grid contactor 13 is turned on, and the external AC power source 4 is electrically connected to the vehicle charger 10 (AC / DC converter). AC power is supplied to the vehicle charger 10 via the grid contactor 13 and the EMI filter FLT.

[0038] The main contactor 11 has two contacts, a main contactor first contact 11a and a main contactor second contact 11b. When the inverter 5 functions as the vehicle-mounted charging device 10, the main contactor second contact 11b is closed and the main contactor first contact 11a is opened. When the inverter 5 is used for driving control of the rotating electrical machine 70, the main contactor first contact 11a is closed and the main contactor second contact 11b is opened, and the inverter positive terminal T5P of the inverter 5 is connected to the DC power supply 3 via the main contactor 11, and the excitation circuit 50 is connected to the DC power supply 3 via the main contactor 11. In addition, when the vehicle is stopped or the power supply to the rotating electrical machine 70 needs to be cut off due to an abnormality, the main contactor first contact 11a and the main contactor second contact 11b can both be in an open state.

[0039] As shown by the dotted line in the figure, the main contactor 11 (first contactor) is closed on the side of the first contact point 11a of the main contactor and the excitation contactor 14 (third contactor) is closed to electrically connect the DC power supply 3 to the DC side terminal T5d of the inverter 5, and the DC power supply 3 is electrically connected to the excitation winding 7r. When the OBC contactor 12 (second contactor) is opened, power is converted between the DC power supply 3 and the rotating electric machine 70 via the inverter 5, and the excitation winding 7r is excited. In other words, the rotating electric machine 70 is driven and controlled via the inverter 5. Of course, at this time, the grid contactor 13 is opened. Furthermore, as shown by the solid line in the figure, the main contactor 11 is closed on the side of the second contact point 11b of the main contactor to electrically connect the DC power source 3 to the output capacitor Cs and the excitation contactor 14 is disconnected. When the OBC contactor 12 is closed, power is converted between the external AC power source 4 and the DC power source 3 via the AC-DC converter (first circuit 1) and the DC converter (second circuit 2) including the inverter 5. Of course, at this time, the grid contactor 13 is closed.

[0040] In this way, by simply changing the connection form between the coil 7 and the exciting winding 7r using the main contactor 11, the OBC contactor 12, and the excitation contactor 14, a circuit capable of switching between the function of driving and controlling the rotating electric machine 70 and the function of charging the DC power supply 3 through the external AC power supply 4 can be realized. That is, the vehicle-mounted charging device 10 can be configured with a simple structure.

[0041] The structure of the AC-DC converter, that is, the first circuit 1, is common to all the first, second, third, and fourth examples, and all of these examples include the excitation circuit 50. Figure 2 As shown in the figures, the first circuit 1 is configured with an inductor L1. In AC-DC conversion, a phase difference is generated between the voltage phase and the current phase due to inductive impedance and capacitive impedance, and the power factor is reduced due to the phase difference. The first circuit 1 as an AC-DC converter is configured with a switching element 1S, and by controlling the switching element 1S, for example, adjusting the current phase, the phase difference can be compensated to correct the power factor. That is, the first circuit 1 is configured to also function as a power factor correction (PFC: Power Factor Correction) circuit that corrects the power factor of the DC power converted from the AC power supplied by the external AC power source 4.

[0042] In the present embodiment, the first circuit 1 as an AC-DC converter is configured with an inductor L1 and a full-bridge circuit using a switching element 1S. By providing a full-bridge circuit, the first circuit 1 can function as a bidirectional converter capable of performing AC-DC conversion and DC-AC conversion. For example, the vehicle-mounted charging device 10 can be used as a device having two functions: a function of charging the DC power supply 3 with power supplied from the external AC power supply 4, and a function of supplying AC power to a device outside the vehicle with power stored in the DC power supply 3.

[0043] In recent years, it is advocated to use the DC power supply 3 of electric vehicles and hybrid vehicles as an emergency power supply in the event of a disaster. The first circuit 1 has a full-bridge circuit, thereby making it possible to use the DC power supply 3 as such an emergency power supply. Of course, it is also possible that, in the case where the use of such a DC power supply 3 is not considered, the first circuit 1 is configured as a unidirectional converter that only performs AC-DC conversion. In this case, it is also possible that the first circuit 1 is configured, for example, with a half-bridge circuit.

[0044] Figure 7 The circuit block diagram shows a charging device 10X of a comparative example of the vehicle-mounted charging device 10 that utilizes the drive control system of the rotating electric machine 70. In addition, in the comparative example, the EMI filter FLT is omitted for simplification. In addition, in this comparative example, the structure (excitation circuit 50) unique to the winding excitation type rotating electric machine is omitted. Like the vehicle-mounted charging device 10 of the present embodiment, the charging device 10X of the comparative example also charges the DC power supply 3 of the vehicle drive device 9 by the power supplied from the external AC power supply 4. Like the vehicle-mounted charging device 10 of the first and second examples, the charging device 10X of the comparative example also has an AC-DC converter (comparative example AC-DC converter 100) and a DC converter (comparative example DC converter 200). Among them, in the vehicle-mounted charging device 10 of the first and second examples, the DC converter (second circuit 2) shares the drive system circuit of the rotating electric machine 70, but in the charging device 10X of the comparative example, it is not the DC converter, but the AC-DC converter (comparative example AC-DC converter 100) that shares the drive system circuit of the rotating electric machine 70. Furthermore, when the rotating electrical machine 70 is a winding-excitation type rotating electrical machine, it is preferable that the DC converter 200 of the comparative example shares the exciting circuit 50 .

[0045] The comparative example AC-DC converter 100 is composed of an inverter 5, a multi-phase coil 7, a single-phase arm 105 connected in parallel to the inverter 5, and an inductor L1 (first inductor). The multi-phase coil 7 is short-circuited at a neutral point 7N, and the inductor L1 (first inductor) and the external AC power supply 4 are connected in series between the neutral point 7N and the midpoint of the single-phase arm 105. The three-phase arms constituting the inverter 5 are connected in parallel to form one arm, and form a full-bridge circuit together with the single-phase arm 105.

[0046] The comparative example DC converter 200 is a step-down DC converter having an arm having a switching element connected in series in a complementary switching control manner and a second inductor L2 connected to the midpoint of the arm. In addition, the comparative example DC converter 200 may be a step-up converter or a step-up / step-down converter. In addition, as described above, when the rotating electrical machine 70 is a winding excitation type rotating electrical machine, the comparative example DC converter 200 may be configured to include an excitation circuit 50.

[0047] The charging device 10X of the comparative example also has the main contactor 11 and the grid contactor 13 which are the same as the vehicle-mounted charging device 10 of the first example and the second example. In addition, the charging device 10X of the comparative example further has an OBC contactor 12 which selectively connects the comparative example AC-DC converter 100 (inverter 5) to the DC power source 3 or connects the comparative example AC-DC converter 100 (inverter 5) to the comparative example DC converter 200. The OBC contactor 12 has two contacts, a first contact 12a of the OBC contactor and a second contact 12b of the OBC contactor. When the inverter 5 functions as the vehicle-mounted charging device (charging device 10X of the comparative example), the second contact 12b of the OBC contactor is closed and the first contact 12a of the OBC contactor is opened. When the inverter 5 is used for driving control of the rotating electrical machine 70 , the OBC contactor first contact 12 a is closed, the OBC contactor second contact 12 b is opened, and the inverter positive terminal T5P of the inverter 5 is connected to the DC power supply 3 via the OBC contactor 12 and the main contactor 11 .

[0048] The rotating electric machine that is the driving force source of the vehicle is set to have a high power density and a small inductance. Therefore, when an external AC power source 4 is connected to the neutral point 7N to form an AC-DC converter as in the charging device 10X of the comparative example, the peak value of the harmonic current of the system current of the external AC power source 4 tends to increase during the AC-DC conversion.

[0049] As a method for suppressing the above-mentioned trend, it is conceivable to increase the control frequency of the inverter 5 and the DC converter 200 included in the comparative example AC-DC converter 100. In the case of increasing their control frequencies, it is also necessary to shorten the control cycle (control frequency) of the control device 8. The high-frequency switching action increases the loss of the switching elements of the comparative example AC-DC converter 100 (inverter 5) and the DC converter 200, resulting in a decrease in the efficiency of the charging device 10X of the comparative example. In addition, as the control device 8, it is necessary to use a microcomputer capable of high-speed operation, etc., resulting in an increase in the cost of the charging device 10X of the comparative example. In view of this, in the charging device 10X of the comparative example, although the coil 7 is used as an inductor, in order to supplement the insufficient inductance in the coil 7, an additional inductor L1 is configured between the external AC power supply 4 and the neutral point 7N of the multi-phase coil 7 to ensure the required inductance. In the charging device 10X of the comparative example, an inductor (second inductor L2 ) is also arranged in the DC converter 200 of the comparative example. Compared with the vehicle-mounted charging device 10 of the first and second examples, the number of inductors increases, and the system cost is likely to increase.

[0050] In view of this, the vehicle-mounted charging device 10 of the first and second examples is configured to suppress the increase in system cost. Specifically, the AC-DC converter (first circuit 1) that requires appropriate inductance in the AC-DC converter and the DC converter that constitute the charging device is configured so as not to use the drive system circuit of the rotating motor 70 (the coil 7 of the rotating motor 70 and the inverter 5 that drives the rotating motor 70). That is, the vehicle-mounted charging device 10 of the first and second examples sets the AC-DC converter (first circuit 1) with appropriate inductance by using the inductor L1 that is independent of the drive system circuit of the rotating motor 70 (the inverter 5, the coil 7, the exciting winding 7r), and can constitute an AC-DC converter that can perform AC-DC conversion while ensuring sufficient performance such as the power factor correction function. In addition, the second circuit 2 (for example, a DC converter) that does not require high inductance is configured to share the drive system circuit (inverter 5, coil 7) of the rotating motor 70, which can reduce the cost of the vehicle-mounted charging device 10. Furthermore, in the first circuit (AC / DC converter), since an appropriate inductance is set for the AC / DC converter by the inductor L1, it is not necessary to control the AC / DC converter with a short control cycle (higher control frequency).

[0051] However, in the vehicle-mounted charging device 10 of the first and second examples, the first circuit 1 that generates the first DC power and the second circuit 2 that generates the second power are connected via the DC link capacitor 6. In the AC-DC conversion formed based on the first circuit 1, the pulsation of the second harmonic component of the frequency of the AC mostly remains in the first DC power. In the vehicle-mounted charging device 10 of the first and second examples, the pulsation component of the first DC power is reduced by the smoothing effect of the DC link capacitor 6. Therefore, the DC link capacitor 6 seeks to have a higher capacity than that of a smoothing capacitor in the drive system of the rotating motor 70. As a result, it is easy to need to make the electrostatic capacitance of the DC link capacitor 6 larger than that in the case of using it only in the rotating motor drive system, which may lead to a larger outer shape of the capacitor and an increase in cost.

[0052] for Figure 4 and Figure 5 For the vehicle-mounted charging device 10 of the third and fourth examples shown, the second circuit 2 is configured as an active decoupling circuit, and the pulsating component of the first DC power is reduced by the active decoupling circuit. Therefore, the first circuit 1 and the second circuit 2 are connected in a manner not passing through other passive components such as the DC link capacitor 6. According to the inventor's experiments and simulations, it can be seen that: compared with the DC link capacitor 6 of the vehicle-mounted charging device 10 of the third and fourth examples, the DC link capacitor 6 of the vehicle-mounted charging device 10 of the first and second examples requires about twice the capacity. Therefore, compared with the vehicle-mounted charging device 10 of the first and second examples, the vehicle-mounted charging device 10 of the third and fourth examples is easy to achieve miniaturization and reduction of system cost.

[0053] Next, the vehicle-mounted charging device 10 of the third and fourth examples will be described. Figure 4 and Figure 5As shown in FIG. 1 , the vehicle-mounted charging device 10 includes a main contactor 11 that disconnects and connects the electrical connection between the DC power source 3 and the DC side terminal T5d of the inverter 5 and the electrical connection between the DC power source 3 and the excitation circuit 50, an OBC contactor 12 that disconnects and connects the electrical connection between the neutral point 7N and the output capacitor Cs, an excitation contactor 14 that disconnects and connects the electrical connection between the excitation circuit 50 and the excitation winding 7r, and a grid contactor 13 that selectively connects the AC side terminal T1a of the first circuit 1 (AC / DC converter) to the external AC power source 4 (disconnects and connects the AC side terminal T1a to the external AC power source 4). In the first and second examples, the main contactor 11 includes two contacts. Since large currents flow through both the first contact 11a and the second contact 11b of the main contactor, the component size of the main contactor 11 tends to become relatively large. In the third and fourth examples of the vehicle charging device 10, the main contactor 11 has only one contact point. Therefore, the main contactor 11 is prevented from becoming larger in size, and the vehicle charging device 10 is prevented from becoming larger in size, and the system cost can be easily reduced.

[0054] As described above, the first circuit 1 is an AC-DC converter, and in the third and fourth examples, the second circuit 2 is an active decoupling circuit. In addition, as described above, in the third and fourth examples, the main contactor 11 is configured with only one contact. The DC side terminal T1d of the first circuit 1 as an AC-DC converter is connected to the DC side terminal T5d of the inverter 5 without passing through other passive components (for example, the DC link capacitor 6). As shown by the dotted line in the figure, when the main contactor 11 and the excitation contactor 14 are closed and the OBC contactor 12 is opened, power is converted between the DC power supply 3 and the rotating electric machine 70 via the inverter 5 and the excitation winding 7r is excited, and the rotating electric machine 70 is driven and controlled. Furthermore, as shown by the solid line in the figure, when the main contactor 11 and the OBC contactor 12 are both closed and the excitation contactor 14 is open, power is converted between the external AC power source 4 and the DC power source 3 via the first circuit 1 as an AC-DC converter and the second circuit 2 as an active decoupling circuit including the inverter 5. Of course, at this time, the grid contactor 13 is closed.

[0055] like Figure 4 and Figure 5As shown, the on-board charging device 10 includes an OBC contactor 12 that disconnects and connects the electrical connection between the neutral point 7N of the coil 7 and the output capacitor Cs. If the OBC contactor 12 is closed, the OBC contactor 12 is turned on, and the neutral point 7N is connected to the negative pole of the DC via the output capacitor Cs. In addition, as described above, the drive control system of the rotating electric machine 70 and the on-board charging device 10 share the main contactor 11. When the grid contactor 13 is closed and the inverter 5 functions as the on-board charging device 10, the main contactor 11 is controlled to be closed and the OBC contactor 12 is closed. That is, in a state where both the main contactor 11 and the OBC contactor 12 are closed and the excitation contactor 14 is opened, power is converted between the external AC power supply 4 and the DC power supply 3 via the AC-DC converter and the active decoupling circuit including the inverter 5.

[0056] When the grid contactor 13 is disconnected and the inverter 5 is used for driving control of the rotating electric machine 70, the control is such that the main contactor 11 and the excitation contactor 14 are closed and the OBC contactor 12 is opened. That is, in a state where the main contactor 11 and the excitation contactor 14 are closed and the OBC contactor 12 is opened, power is converted between the DC power supply 3 and the rotating electric machine 70 via the inverter 5.

[0057] Thus, in the third and fourth examples, only by changing the connection form between the coil 7 and the exciting winding 7r using the OBC contactor 12 and the excitation contactor 14, a circuit capable of switching between the function of driving and controlling the rotating electric machine 70 and the function of charging the DC power supply 3 through the external AC power supply 4 can be realized. That is, the vehicle-mounted charging device 10 can be configured with a simple structure.

[0058] Figure 6 The circuit diagram is shown in Figure 1 for easy understanding. Figure 4 and Figure 5 The circuit block diagram is shown separately by function. The AC-DC converter (first circuit 1) performs voltage boosting and adjusts the power factor of the grid current Igrid supplied from the external AC power source 4 to a value close to "1". Among them, a pulsating component caused by the AC frequency of the external AC power source 4 is superimposed on the first DC power output from the AC-DC converter. Specifically, the pulsation of the second harmonic component of the AC frequency of the external AC power source 4 is superimposed. The second circuit 2, which functions as an active decoupling circuit, reduces the pulsation of the second harmonic component, and supplies the second DC power with suppressed pulsation, preferably the second DC power with pulsation removed, to the DC power source 3 to charge the DC power source 3.

[0059] Here, if the AC voltage supplied from the external AC power source 4 is set to "grid voltage Vgrid" and the AC current is set to "grid current Igrid", the input power Pin supplied from the external AC power source 4 is expressed by the following formula (1). Furthermore, if it is assumed that the input power Pin is converted into the first DC power with a power factor of "1", the relationship between the input power Pin and the first DC power can be approximated by the following formula (2). Formula (2) shows that the first DC power includes a DC component Pdc and an AC component Prpl.

[0060] Pin=Vgrid·Igrid···(1)

[0061] Pin≈Pdc+Prpl···(2)

[0062] The active decoupling circuit has the following function: a current corresponding to the AC component Prpl included in the formula (2), that is, the AC component Prpl included in the first DC power, flows in the active decoupling circuit so that the output power Pout output to the DC power supply 3 becomes only the DC component Pdc included in the formula (2) (formula (3)). As shown in the following formula (4), the second circuit 2 as the active decoupling circuit operates in a manner that the power in the output capacitor Cs, that is, the capacitor power Pcs, is consistent with the AC component Prpl of the first DC power.

[0063] Pout=Pdc···(3)

[0064] Prpl=Pcs···(4)

[0065] Since the capacitor power Pcs satisfies the relationship of the following equation (5) between the capacitor voltage Vcs and the capacitor current Ics, the capacitor power Pcs can be controlled by appropriately controlling the capacitor current Ics.

[0066] Pcs=Vcs·Ics···(5)

[0067] As described above, the inductance of the coil 7 of the rotating electric machine 70 is small, and therefore, in the active decoupling circuit, the inductor (coil 7) is used not for storing energy but for passing current. In the vehicle-mounted charging device 10 of the third and fourth examples, the capacitor current Ics is made not a so-called continuous current but a discontinuous current based on pulse width modulation to achieve the decoupling effect by the active decoupling circuit.

[0068] As described above, the inverter 5 is configured to have an arm in which an upper switching element 5U and a lower switching element 5L are connected in series in a manner that multiple arms are connected in parallel between the positive and negative poles of the DC in correspondence with the number of phases of the multi-phase AC. In the present embodiment, the inverter 5 is configured to have three arms. When the inverter 5 functions as an active decoupling circuit, multiple upper switching elements 5U are simultaneously switched and controlled, and multiple lower switching elements 5L are simultaneously switched and controlled. That is, the inverter 5 having a multi-phase arm corresponding to the multi-phase AC can be used as an inverter (switching circuit) having a single-phase arm. The current is dispersed and flows in multiple arms, so even if the inverter 5 is used as part of the vehicle-mounted charging device 10, it is easy to suppress the consumption of the inverter 5.

[0069] In addition, in the switch control, the capacitor current command I ＊ cs, generating a switch control signal (switching pulse) for the upper switching element 5U and the lower switching element 5L. ＊ The phase of cs is consistent with the phase of the grid voltage Vgrid and the phase of the grid current Igrid. In addition, the phase of the capacitor voltage Vcs is delayed by π / 2 relative to the capacitor current Ics.

[0070] As described above, the inverter 5 performs switching control on the plurality of upper switching elements 5U and the plurality of lower switching elements 5L so that the phase of the current flowing in the output capacitor Cs is consistent with the phase of the AC current in the AC-DC converter. The active decoupling circuit attenuates the AC harmonic components in the AC-DC converter by causing the AC harmonic components to flow in the output capacitor Cs. The phase of the current flowing in the output capacitor Cs can be made consistent with the phase of the AC current in the AC-DC converter, thereby improving the attenuation effect.

[0071] In addition, as described above, in this embodiment, it is necessary to allow a current (capacitor current Ics) corresponding to the pulsating component of the first DC power, that is, the AC component Prpl, to flow through the active decoupling circuit. Therefore, the capacitor current command Ics is set in consideration of the magnitude relationship with the output voltage (=battery voltage Vbat) for the DC power supply 3. ＊ cs.

[0072] The capacitor voltage Vcs needs to be a voltage lower than the battery voltage Vbat. In addition, a pulsation corresponding to the AC component Prpl of the first DC power is generated in the capacitor voltage Vcs, and therefore, the capacitor voltage Vcs is set to a voltage lower than the battery voltage Vbat in consideration of the amplitude of the pulsation. That is, the command value of the capacitor voltage Vcs, i.e., the capacitor voltage command V ＊ The amplitude of cs is "V ＊cs_peak" is preferably set so that the following formula (6) is satisfied when the amplitude (value from the amplitude center to the peak value) of the AC component "Vrpl" of the voltage in the first DC power is set to "Vrpl_peak".

[0073] V ＊ cs_peak<Vbat-Vrpl_peak ··· (6)

[0074] In addition, as the charging of the DC power supply 3 proceeds, the battery voltage Vbat increases. Therefore, if the capacitor voltage command V ＊ If cs is constant, the difference between the capacitor voltage Vcs and the battery voltage Vbat increases, the capacitor current Ics increases, and the loss also increases. Therefore, the capacitor voltage Vcs preferably satisfies equation (6) and increases as the battery voltage Vbat increases. That is, the capacitor voltage command V ＊ cs is set so as to satisfy the expression (6) and increase as the battery voltage Vbat increases.

[0075] In addition, regarding the third and fourth examples, the following cases are described: when the inverter 5 functions as an active decoupling circuit, the plurality of upper switching elements 5U are simultaneously switched and the plurality of lower switching elements 5L are simultaneously switched. Regarding the first and second examples in which the second circuit 2 is a DC converter, since they are well-known structures, detailed descriptions of the operation of the DC converter are omitted, but similarly to the third and fourth examples, the plurality of upper switching elements 5U are simultaneously switched and the plurality of lower switching elements 5L are simultaneously switched.

[0076] However, if currents of different magnitudes flow to the coil 7, torque is generated in the rotor 72. The charging of the DC power supply 3 is performed when the vehicle is stopped, so it is not preferred to generate torque on the rotor 72. For example, it is also considered to cut off the power transmission from the rotor 72 to the wheel by a clutch, etc., or to limit the rotation of the output member connected to the wheel and the rotation of the rotor 72 by a so-called parking brake, etc. However, in these cases, the mechanism of the vehicle drive device 9 is also complicated, or a mechanical load is generated on the gears of the vehicle drive device 9. The commonality in the first to fourth examples is that multiple upper switching elements 5U are switched at the same time, and multiple lower switching elements 5L are switched at the same time, so that almost the same magnitude of current flows to each of the multi-phase coils 7. Therefore, using the coil 7 for the vehicle-mounted charging device 10 can also make the rotor 72 generate almost no torque.

[0077] Among them, when the magnitude of the current flowing through the multi-phase coils 7 differs due to individual differences or errors of the coils 7, even a small difference may generate torque on the rotor 72. For example, when the rotating electrical machine 70 is a permanent magnet type rotating electrical machine (PMSM) having permanent magnets in the rotor 72, the rotor 72 is always magnetized, and therefore torque may be generated on the rotor 72. However, as in the present embodiment, when the rotating electrical machine 70 is a winding excitation type synchronous rotating electrical machine (EESM), as long as the exciting winding 7r is not energized, no exciting is generated on the rotor 72. When the inverter 5 and the coil 7 are used as the on-vehicle charging device 10, the exciting contactor 14 is disconnected and the exciting winding 7r is not excited, and no exciting is generated on the rotor 72. Therefore, even if the magnitude of the current flowing through the multi-phase coils 7 differs due to individual differences or errors of the coils 7, it is possible to prevent the rotor 72 from generating torque in common in the first to fourth examples. That is, in the vehicle-mounted charging device 10 of the present embodiment in which the rotating electric machine 70 is a winding-excitation type synchronous rotating electric machine, the rotor 72 is more likely not to generate torque than in the case in which the rotating electric machine 70 is a permanent magnet type rotating electric machine. Therefore, the concern about the mechanical load generated by the gears of the vehicle drive device 9 and the like is further reduced, and the vehicle-mounted charging device 10 can be appropriately configured.

[0078] According to the first and second examples described above, the AC-DC converter and the DC converter that constitute the vehicle-mounted charging device 10, which require appropriate inductance, are configured by using the excitation circuit 50 instead of the driving system circuit of the rotating electric machine 70 (the coil 7 of the rotating electric machine 70 and the inverter 5 that drives the rotating electric machine 70). In the case where the vehicle-mounted charging device 10 uses the coil 7 of the rotating electric machine 70, the inductance of the coil 7 is small, and it is sometimes difficult to ensure the required performance. However, according to this structure, by using the excitation circuit 50 instead of the coil 7 of the rotating electric machine 70 and setting a circuit with appropriate inductance, it is possible to configure an AC-DC converter that can perform AC-DC conversion while ensuring sufficient performance such as a power factor correction function. In addition, a DC converter that does not require high inductance can be configured using the stator coil (coil 7) and the inverter 5, and the cost of the vehicle-mounted charging device 10 can be reduced. In addition, since it is possible to set an appropriate inductance for the AC-DC converter, it is not necessary to control the AC-DC converter with a short control cycle (higher control frequency), and the loss of the switching element 1S constituting the AC-DC converter is also easily reduced. Therefore, the system efficiency of the vehicle-mounted charging device 10 can also be easily improved.

[0079] According to the third and fourth examples described above, the AC-DC converter that requires appropriate inductance is configured without using the driving system circuit of the rotating electric machine 70 (the coil 7 of the rotating electric machine 70 and the inverter 5 that drives the rotating electric machine 70). In the case where the on-vehicle charging device 10 uses the coil 7 of the rotating electric machine 70, the inductance of the coil 7 is small, and thus it is sometimes difficult to ensure the required performance. However, according to this configuration, by using the excitation circuit 50 without using the coil 7 of the rotating electric machine 70 and setting a circuit with appropriate inductance, it is possible to configure an AC-DC converter that can perform AC-DC conversion while ensuring sufficient performance such as a power factor correction function. In addition, it is possible to set an appropriate inductance for the AC-DC converter, thereby eliminating the need to control the AC-DC converter with a shorter control cycle (higher control frequency), and the loss of the switching element 1S constituting the AC-DC converter is also easily reduced. Therefore, the system efficiency of the on-vehicle charging device 10 is also easily improved. In addition, since a pulsating component is superimposed on the DC converted from the AC by the AC-DC converter, it is often the case that a DC converter is configured via a decoupling capacitor for reducing the pulsating component at the rear stage of the AC-DC converter. According to this structure, the pulsation component can be reduced by the active decoupling circuit connected to the AC-DC converter without passing through the decoupling capacitor, so the circuit scale can be easily suppressed to be small. In addition, as the switching element and inductor constituting the active decoupling circuit, the inverter 5 for driving the rotating electric machine 70 and the coil 7 of the rotating electric machine 70 can be used together, and the circuit scale of the entire vehicle-mounted system can also be easily suppressed to be small.

Claims

1. An on-vehicle charging device that charges a DC power supply of a vehicle drive device by power supplied from an external AC power supply, the vehicle drive device comprising: a winding-excited rotating electric machine having a stator having multi-phase stator coils interconnected at a neutral point and a rotor having an exciting winding that generates an exciting magnetic flux and serves as a driving force source for wheels; the DC power supply; an inverter that is connected between the stator coil and the DC power supply and converts power between DC and multi-phase AC; and an excitation circuit that is connected between the exciting winding and the DC power supply and excites the exciting winding, The vehicle-mounted charging device is characterized by comprising: a first circuit including the excitation circuit and converting power between the AC power of the external AC power source and a first DC power; and a second circuit including the inverter, the multi-phase stator coils, and an output capacitor, and generating a second DC power for charging the DC power supply from the first DC power, The output capacitor is connected between the neutral point of the stator coil and a negative pole of direct current.

2. The vehicle-mounted charging device according to claim 1, characterized in that: have: a first contactor that disconnects and connects the electrical connection between the DC power supply and the DC side terminal of the inverter and the electrical connection between the DC power supply and the excitation circuit; a second contactor that disconnects and connects the electrical connection between the neutral point and the output capacitor; as well as a third contactor, which disconnects and connects the electrical connection between the excitation circuit and the excitation winding, The first circuit is an AC-DC converter, The second circuit is an active decoupling circuit. The DC side terminal of the AC-DC converter is connected to the DC side terminal of the inverter without passing through other passive components, In a state where the first contactor and the third contactor are closed and the second contactor is open, power is converted between the DC power supply and the rotating electric machine via the inverter, and the field winding is excited. In a state where the first contactor and the second contactor are both closed and the third contactor is open, power is converted between the external AC power source and the DC power source via the AC-DC converter and the active decoupling circuit including the inverter.

3. The vehicle-mounted charging device according to claim 1, characterized in that: have: a first contactor that opens and closes the electrical connection between the output capacitor and the DC power supply, and opens and closes the electrical connection between the DC power supply and the DC side terminal of the inverter and between the DC power supply and the excitation circuit in a manner complementary to the output capacitor; a second contactor that disconnects and connects the electrical connection between the neutral point and the output capacitor; as well as a third contactor, which disconnects and connects the electrical connection between the excitation circuit and the excitation winding, The first circuit is an AC-DC converter, The second circuit is a DC converter, In a state where the first contactor is closed and the DC power supply is electrically connected to the DC side terminal of the inverter, and the third contactor is closed and the second contactor is open, power is converted between the DC power supply and the rotating electric machine via the inverter and the field winding is excited. In a state where the first contactor is closed and the DC power supply is electrically connected to the output capacitor, and the third contactor is open and the second contactor is closed, power is converted between the external AC power supply and the DC power supply via the AC-DC converter and the DC converter including the inverter.

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