Integrated system of electric vehicle on-board charging and drive motor and working method thereof

Abstract

The application discloses an integrated system of vehicle-mounted charging and driving motor of an electric vehicle and a working method thereof, and belongs to the technical field of charging of electric vehicles. The application aims at the fact that the existing charging device and driving device of the electric vehicle are less combined in structure and function, and the working mode is single, so that the power density is low. The application comprises a switching unit, an input unit, a motor unit, an energy conversion unit and a battery unit, and the working method comprises a charging mode, a driving mode, an electric energy feedback mode, a braking energy feedback mode and a fault-tolerant mode. The application effectively improves the power density of the integrated system and different requirements of the electric vehicle.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electric vehicle charging, and particularly relates to an integrated system of vehicle-mounted charging and driving motor of an electric vehicle and a working method thereof. BACKGROUND

[0002] At present, electric vehicles are in a stage of rapid development, and automobile enterprises in various countries have accelerated the pace of developing electric vehicles. The core technical problems of electric vehicles include two aspects: vehicle-mounted charging technology and motor driving technology, which have a deep influence on the performance and development of electric vehicles and are a prerequisite for promoting the development of electric vehicles.

[0003] There are mainly two ways for electric vehicle charging: one is a charging pile which can be fixed on the ground or wall and is installed in public buildings such as public buildings, shopping malls, public parking lots and the like and residential parking lots or charging stations. The input end of the charging pile is directly connected with an alternating current power grid, and the output end is provided with a charging plug for charging the electric vehicle, but there are problems of high construction cost and large occupied area; the other is to charge the power battery through a charging machine installed on the electric vehicle, i.e. a vehicle-mounted charging machine. Compared with the charging pile, the vehicle-mounted charging machine has advantages in power density and information integration and is convenient and flexible.

[0004] The motor driving system of the electric vehicle is a link between the energy storage system and the wheels, and its function is to convert the energy output by the energy storage system into mechanical energy to push the vehicle to overcome various rolling resistance, air resistance, acceleration resistance and climbing resistance, and to convert the kinetic energy into electric energy to feed back to the energy storage system during braking.

[0005] The electric vehicle charging device and driving device in the prior art are not integrated in structure and function, occupy a large volume of the electric vehicle, and the working mode in the working method is single, which cannot meet different needs of the electric vehicle. SUMMARY

[0006] In order to solve the above problems, the application provides an integrated system of vehicle-mounted charging and driving motor of an electric vehicle and a working method thereof, which adopts a modular structure, selects different working modes in the working method, and realizes structural integration and comprehensive functional integration of vehicle-mounted charging and driving motor.

[0007] The application provides an integrated system of vehicle-mounted charging and driving motor of an electric vehicle in the first aspect, which comprises:

[0008] The switch unit comprises a first port group, a second port group and a third port group, the first port group comprises at least three ports, the second port group comprises at least three ports, and the third port group comprises at least three ports;

[0009] The energy conversion unit comprises a power factor correction circuit, a DC bus capacitor, a primary three-phase circuit, a transformer, a high-voltage charging circuit and a low-voltage charging circuit, the second port group of the switch unit is connected with the power factor correction circuit, and the third port group of the switch unit is connected with the primary three-phase circuit.

[0010] The input unit comprises an AC transmission circuit, a DC transmission circuit and a photovoltaic input circuit, the AC transmission circuit is connected with the first port group through a switch K3, the DC transmission circuit is connected across the DC bus capacitor through a switch K2, and the photovoltaic input circuit is connected with the low-voltage charging circuit through a switch K1.

[0011] The battery unit comprises a high-voltage power battery and a low-voltage storage battery, the high-voltage power battery is connected across the high-voltage charging circuit, and the low-voltage storage battery is connected across the low-voltage charging circuit.

[0012] The motor unit comprises a three-phase motor, a single-phase motor and a DC motor, the three-phase motor is connected with the first port group through a switch K4, the single-phase motor is connected with the first port group through a switch K5, and the DC motor is connected across the DC bus capacitor through a switch K6.

[0013] Further, the high-voltage charging circuit comprises a first bridge arm, a second bridge arm and a third bridge arm which are connected in parallel and have the same structure, each bridge arm comprises two field effect tubes connected in series, the low-voltage charging circuit comprises a first-stage step-down chopper circuit and a low-voltage resonant circuit, and the low-voltage resonant circuit is connected across one field effect tube of the third bridge arm.

[0014] Further, the power factor correction circuit comprises three bridge arms connected in parallel, each bridge arm comprises two field effect tubes connected in series, three ports of the second port group of the switch unit are connected with the midpoints of the three bridge arms of the power factor correction circuit respectively, the primary three-phase circuit comprises three bridge arms connected in parallel, each bridge arm comprises two field effect tubes connected in series, and three ports of the third port group of the switch unit are connected with the midpoints of the three bridge arms of the primary three-phase circuit respectively.

[0015] The second aspect of the present application provides a working method of the integrated system of the on-board charging and driving motor of the electric vehicle, and the working method is realized based on the integrated system of the on-board charging and driving motor of the electric vehicle in the first aspect of the present application, and the working method comprises a charging mode.

[0016] The charging mode comprises a parking charging mode, in the parking charging mode, the AC transmission circuit or the DC transmission circuit is turned on, and the parking charging mode comprises a parking high-voltage charging mode and a parking low-voltage charging mode.

[0017] In the parking high-voltage charging mode, the low-voltage charging circuit is disconnected, the primary three-phase circuit and the high-voltage charging circuit form a three-phase CLLC bidirectional DC-DC resonant converter to charge the high-voltage power battery.

[0018] In the parking low-voltage charging mode, the high-voltage power battery is disconnected from the high-voltage charging circuit, the first step-down chopper circuit and the low-voltage resonant circuit of the low-voltage charging circuit are connected, two bridge arms of the primary three-phase circuit and two bridge arms of the high-voltage charging circuit work to form a two-phase CLLC bidirectional DC-DC resonant converter, the third bridge arm of the high-voltage charging circuit and the low-voltage resonant circuit of the low-voltage charging circuit form a second step-down chopper circuit, and the DC bus voltage is regulated by the first step-down chopper circuit and the second step-down chopper circuit to charge the low-voltage storage battery.

[0019] Further, the charging mode includes a driving charging mode, and the driving charging mode includes a driving low-voltage charging mode and a driving power battery low-voltage charging mode.

[0020] In the driving low-voltage charging mode, the first step-down chopper circuit is disconnected, the photovoltaic input circuit is connected to the second step-down chopper circuit to charge the low-voltage storage battery.

[0021] In the driving power battery low-voltage charging mode, the high-voltage power battery is connected to the first step-down chopper circuit and the second step-down chopper circuit to charge the low-voltage storage battery.

[0022] Further, the working method includes a driving mode, in which the low-voltage charging circuit is disconnected, the high-voltage charging circuit is connected to the high-voltage power battery, the electrical energy of the high-voltage power battery is boosted to the DC bus voltage through the three-phase CLLC bidirectional DC-DC resonant converter formed by the primary three-phase circuit and the high-voltage charging circuit, the DC bus voltage drives the DC motor, and the DC bus voltage is converted into AC power by the power factor correction circuit working in the inverter state to drive the three-phase motor or the single-phase motor.

[0023] Further, the working method includes an electrical energy feedback mode, in which the low-voltage charging circuit is disconnected, the high-voltage charging circuit is connected to the high-voltage power battery, the electrical energy of the high-voltage power battery is boosted to the DC bus voltage through the three-phase CLLC bidirectional DC-DC resonant converter formed by the primary three-phase circuit and the high-voltage charging circuit, and the DC bus voltage is output through the DC transmission circuit; the DC bus voltage is converted into AC power by the power factor correction circuit working in the inverter state, and the AC power is output through the AC transmission circuit.

[0024] Further, the working method comprises a braking energy feedback mode, in the energy feedback mode, the power factor correction circuit works in a rectification state, and electric energy generated in a motor unit braking process is converted into high-voltage direct current; a primary side three-phase circuit and a high-voltage charging circuit form a CLLC bidirectional direct-current-direct-current resonant converter to convert the high-voltage direct current into a voltage required by a high-voltage power battery or a low-voltage storage battery for charging the high-voltage power battery or the low-voltage storage battery.

[0025] Further, the working method comprises a fault-tolerant mode, the fault-tolerant mode comprises a power factor correction circuit fault-tolerant mode, the power factor correction circuit fault-tolerant mode comprises a three-phase state fault-tolerant mode and a single-phase state fault-tolerant mode;

[0026] In the three-phase state fault-tolerant mode, when a certain bridge arm of the power factor correction circuit fails, any port in the third port group is turned on, so that the remaining two bridge arms of the power factor correction circuit and one bridge arm in the primary side three-phase circuit form a three-phase power factor correction circuit, and the remaining two bridge arms of the primary side three-phase circuit and the high-voltage charging circuit form a two-phase CLLC bidirectional direct-current-direct-current resonant converter;

[0027] In the single-phase state fault-tolerant mode, when a certain bridge arm of the power factor correction circuit fails, the remaining two ports of the second port group are turned on; when any two bridge arms of the power factor correction circuit fail, the remaining one port in the second port group and any port in the third port group are turned on, so that the remaining one bridge arm of the power factor correction circuit and one bridge arm in the primary side three-phase circuit form a single-phase power factor correction circuit, and the remaining two bridge arms of the primary side three-phase circuit and the high-voltage charging circuit form a two-phase CLLC bidirectional direct-current-direct-current resonant converter.

[0028] Further, the fault-tolerant mode comprises a primary side three-phase electric circuit fault mode and a high-voltage charging circuit fault mode;

[0029] In the primary side three-phase electric circuit fault mode, the trigger pulse of the fault bridge arm is blocked, and the bridge arm corresponding to the fault bridge arm in the high-voltage charging circuit is also blocked;

[0030] In the high-voltage charging circuit fault mode, the trigger pulse of the fault bridge arm is blocked, and the bridge arm corresponding to the fault bridge arm in the primary side three-phase circuit is also blocked.

[0031] As described above, the application has the following effects:

[0032] 1. Each structural unit in the integrated system of the electric vehicle on-board charging and driving motor adopts a modular structure, and different working modes are realized by changing the working states of the units;

[0033] 2、The integrated system of the present application can not only work in the basic charging mode, but also can realize the motor driving mode, the electric energy feedback mode, the energy feedback mode and the fault tolerance mode, so that the working method contains comprehensive working modes to meet the needs of different working scenes and working environments of the electric vehicle.

[0034] 3、In the charging mode, the bidirectional operation of the field effect tube in the power factor correction circuit can be used as the power factor correction circuit or the voltage type inverter to realize the transmission of electric energy in different directions; and the switching of the switching unit is used to realize the single-phase power factor correction circuit and the three-phase power factor correction circuit to meet the needs of single-phase alternating current input and three-phase alternating current input.

[0035] 4、The high-voltage charging circuit and the low-voltage charging circuit of the present application are integrated, the high-voltage charging circuit and the primary three-phase circuit form a three-phase CLLC bidirectional DC-DC resonant converter, the field effect tube in the high-voltage charging circuit and the primary three-phase circuit is controlled to realize the three-phase CLLC bidirectional DC-DC resonant converter and the two-phase CLLC bidirectional DC-DC resonant converter to meet the use of different voltage grades, and the high-voltage charging and the low-voltage charging two working modes can be realized.

[0036] 5、The integrated system of the present application meets the use requirements under the automobile driving condition, on the one hand, the vehicle-mounted photovoltaic circuit can be selected to charge the storage battery according to the light intensity; on the other hand, the high-voltage power battery pack can charge the storage battery through the low-voltage charging circuit while providing electric energy for the vehicle power system to ensure the vehicle operation. The energy feedback can be realized when the automobile brakes, and the storage to the high-voltage power battery or the low-voltage storage battery can be selected according to the size of the feedback energy.

[0037] 6、The integrated system and the working method of the present application can realize the multidirectional flow of energy, not only the electric energy generated from the power grid, the direct current power supply or the photovoltaic power generation device can be used to charge the high-voltage power battery pack and the storage battery of the electric vehicle, but also the electric energy in the high-voltage power battery pack can be fed back to the input unit to realize the feedback utilization of the electric energy; and the energy feedback when the automobile brakes can be used to convert the feedback energy into electric energy to charge the high-voltage power battery or the low-voltage storage battery.

[0038] 7、The integrated system of the present application further includes a fault tolerance mode, when the bridge arm in the power factor correction circuit, the primary three-phase circuit and the high-voltage charging circuit fails, the system operation is not affected in the charging mode, the driving mode or the energy feedback mode, and the fault tolerance rate of the system is improved. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 It is the circuit principle diagram of the integrated system of the electric vehicle vehicle-mounted charging and driving motor of the embodiment of the present application;

[0040] Figure 2 Circuit schematic for three-phase AC input mode of embodiment of the invention;

[0041] Figure 3 Circuit schematic for single-phase AC input mode of embodiment of the invention;

[0042] Figure 4 Circuit schematic for DC input mode of embodiment of the invention;

[0043] Figure 5 Circuit schematic for photovoltaic input mode of embodiment of the invention;

[0044] Figure 6 Circuit schematic for parked high-voltage charging mode of embodiment of the invention;

[0045] Figure 7 Circuit schematic for parked low-voltage charging mode of embodiment of the invention;

[0046] Figure 8 Circuit schematic for driving low-voltage charging mode of embodiment of the invention;

[0047] Figure 9 Circuit schematic for driving low-voltage charging mode of embodiment of the invention;

[0048] Figure 10 Circuit schematic for three-phase motor drive mode of embodiment of the invention;

[0049] Figure 11 Circuit schematic for single-phase motor drive mode of embodiment of the invention;

[0050] Figure 12 Circuit schematic for DC motor drive mode of embodiment of the invention;

[0051] Figure 13 Circuit schematic for three-phase AC energy feedback mode of embodiment of the invention;

[0052] Figure 14 Circuit schematic for DC energy feedback mode of embodiment of the invention;

[0053] Figure 15 Circuit schematic for single-phase AC energy feedback mode of embodiment of the invention;

[0054] Figure 16 Circuit schematic for braking energy feedback mode for charging high-voltage traction battery of embodiment of the invention;

[0055] Figure 17 Circuit diagram for charging low voltage battery in braking energy feedback mode of embodiment of the present application;

[0056] Figure 18 Circuit diagram for one bridge arm fault tolerant mode of power factor correction circuit in single phase working state of embodiment of the present application;

[0057] Figure 19 Circuit diagram for one bridge arm fault tolerant mode of power factor correction circuit in single phase working state of embodiment of the present application;

[0058] Figure 20 Circuit diagram for two bridge arm fault tolerant mode of power factor correction circuit in single phase working state of embodiment of the present application;

[0059] Figure 21 Circuit diagram for one bridge arm fault tolerant mode of primary side three phase circuit of embodiment of the present application. DETAILED DESCRIPTION

[0060] The present application is herein described, by way of example only, with reference to certain embodiments thereof. It is to be understood that variations and modifications of the embodiments can be made while still remaining within the spirit and scope of the present application. The embodiments and features of the present application as described herein can be combined with each other, as appropriate, without departing from the spirit and scope of the present application.

[0061] It is to be understood that the above description is intended to be illustrative and not restrictive. Many embodiments as well as many applications besides the examples provided can be made by one skilled in the art without departing from the scope of the disclosure. It will be apparent to those having ordinary skill in the art that various modifications and variations can be made to the specific embodiments without departing from the spirit or scope of the disclosure. Like reference numerals can be used to denote like elements throughout the specification and figures.

[0062] As shown in FIG. 1, the integrated system of the present application includes a switch unit, an input unit, a motor unit, an energy conversion unit and a battery unit. Figure 1

[0063] The switch unit includes a first port group, a second port group and a third port group, each of which includes at least three ports. In the present embodiment, the first port group includes ports N1, N2 and N3, the second port group includes ports N4, N5 and N6, and the third port group includes ports N7, N8 and N9. 6a 6b 6c 7a 7b ​​​​​and port N 7c Three ports, the third port group includes port N 8a , port N 8b and port N 8c Three ports, the three ports of the first port group can be connected and conducted with the three ports of the second port group two by two, and the three ports of the first port group can also be connected and conducted with the three ports of the third port group two by two. In the specific application process, the number of port groups can be increased as needed, and the number of ports in the port group can also be increased as needed to increase the expansion of other circuits or existing circuits.

[0064] The input unit includes an alternating current transmission circuit, a direct current transmission circuit and a photovoltaic input circuit. The alternating current transmission circuit is connected to the port N 6a , port N 6b and port N 6c of the first port group through switch K3. The direct current transmission circuit is connected to both ends of the direct current bus capacitor C dc through switch K2. The photovoltaic input circuit is connected to the low-voltage charging circuit through switch K1.

[0065] The motor unit includes a three-phase motor, a single-phase motor and a direct current motor. The three-phase motor is connected to the port N 6a , port N 6b and port N 6c of the first port group through switch K4. The single-phase motor is connected to the port N 6b and port N 6c of the first port group through switch K5. The direct current motor is connected to both ends of the direct current bus capacitor C dc through switch K6.

[0066] The energy conversion unit includes a power factor correction circuit, a direct current bus capacitor C dc , a primary three-phase circuit, a transformer, a high-voltage charging circuit and a low-voltage charging circuit.

[0067] In a specific embodiment, the power factor correction circuit includes three bridge arms with the same structure and connected in parallel, each bridge arm includes two silicon carbide field effect transistors connected in series. As shown in the figure, the three bridge arms are a bridge arm composed of field effect transistor S1 and field effect transistor S4, a bridge arm composed of field effect transistor S3 and field effect transistor S6, and a bridge arm composed of field effect transistor S5 and field effect transistor S2. For the sake of description, the three bridge arms of the power factor correction circuit are defined as S1-S4 bridge arm, S3-S6 bridge arm and S5-S2 bridge arm, and the three ports N 7a , N 7b and N 7cThe midpoints of the S1-S4 bridge arm, the S3-S6 bridge arm and the S5-S2 bridge arm are connected respectively, and the two ends of the DC bus capacitor C dc are connected to the two ends of the S5-S2 bridge arm.

[0068] The transformer comprises a transformer T1, a transformer T2 and a transformer T3, and each of the three transformers comprises a primary winding and a secondary winding.

[0069] The primary three-phase circuit comprises three parallel bridge arms which are connected in parallel and have the same structure, each bridge arm comprising two field effect tubes connected in series, as shown in the figure, the three bridge arms are a bridge arm composed of a field effect tube Q1 and a field effect tube Q2, a bridge arm composed of a field effect tube Q3 and a field effect tube Q4, and a bridge arm composed of a field effect tube Q5 and a field effect tube Q6, for the sake of description, the three bridge arms of the primary three-phase circuit are named as a Q1-Q2 bridge arm, a Q3-Q4 bridge arm and a Q5-Q6 bridge arm, the two ends of the Q1-Q2 bridge arm are connected to the two ends of the DC bus capacitor C dc , a first primary side resonant circuit is arranged on the Q1-Q2 bridge arm, the first primary side resonant circuit is composed of a resonant inductor L rp1 , a resonant capacitor C rp1 and an excitation inductor L m1 , a second primary side resonant circuit composed of a resonant inductor L rp2 , a resonant capacitor C rp2 and an excitation inductor L m2 is arranged on the Q3-Q4 bridge arm, and a third primary side resonant circuit composed of a resonant inductor L rp3 , a resonant capacitor C rp3 and an excitation inductor L m3 is arranged on the Q5-Q6 bridge arm, the excitation inductors L m1 , L m2 and L m3 are connected to the two sides of the primary windings of the transformer T1, the transformer T2 and the transformer T3 respectively, and the three ports N 8a , N 8b and N 8c of the third port group of the switch unit are connected to the midpoints a, b and c of the three bridge arms of the primary three-phase circuit respectively, and one end of the resonant inductors L rp1 , L rp2 and L rp3 is connected to the midpoints a, b and c of the three bridge arms respectively.

[0070] The high-voltage charging circuit comprises a maintenance capacitor C0 and three parallel bridge arms which are connected in parallel and have the same structure, each bridge arm comprising two field effect tubes connected in series, as shown in the figure, the three bridge arms are a bridge arm composed of a field effect tube Q7 and a field effect tube Q8, a bridge arm composed of a field effect tube Q9 and a field effect tube Q 10The bridge arm is formed by the field-effect transistor Q. 11 and field-effect transistor Q 12 For ease of description, the three bridge arms of the primary-side three-phase circuit are named Q7-Q8 bridge arms, Q9-Q8 bridge arms, and Q9-Q8 bridge arms, respectively. 10 Bridge arm and Q 11 -Q 12 The bridge arm, wherein the sustaining capacitor C0 is connected in parallel to Q 11 -Q 12 Both ends of the bridge arm; a first secondary resonant circuit is provided on the Q7-Q8 bridge arm, the first secondary resonant circuit being composed of a resonant inductor L rs1 and resonant capacitor C rs1 Composition, Q9-Q 10 The bridge arm is equipped with a resonant inductor L rs2 and resonant capacitor C rs2 This forms the second secondary resonant circuit, Q 11 -Q 12 The bridge arm is equipped with a resonant inductor L rs3 and resonant capacitor C rs3 This forms the third secondary resonant circuit, with resonant capacitor C. rs1 C rs2 C rs3 One end of the capacitor is connected to the midpoints d, e, and f of the three bridge arms, respectively, and the resonant capacitor C... rs3 A switch N1 is provided between the point and the midpoint f.

[0071] The low-voltage charging circuit includes a first-stage buck chopper circuit and a low-voltage resonant circuit, as shown in the figure. The first-stage buck chopper circuit includes a field-effect transistor Q. 13 Freewheeling diode D1, filter inductor L4 and sustaining capacitor C1, field-effect transistor Q 13 After being connected in series with the freewheeling diode D1, it is connected in parallel to Q9-Q. 10 At both ends of the bridge arm, the two ends of the holding capacitor C1 are connected in parallel to Q. 11 -Q 12 At both ends of the bridge arm, the sustaining capacitor C1 and the field-effect transistor Q 11 A switch N2 is provided between them, and one end of the filter inductor L4 is connected to the field-effect transistor Q. 13 Between the freewheeling diode D1 and the filter inductor L4, the other end is connected between the sustaining capacitor C1 and the switch N2; the low-voltage resonant circuit includes a filter inductor L5 and a sustaining capacitor C2, which are connected in series and then in parallel to the field-effect transistor Q. 12 At both ends, the filter inductor L5 and the field-effect transistor Q 12 A switch N3 is installed between them;

[0072] The battery unit comprises a high-voltage power battery and a low-voltage storage battery, the high-voltage power battery is connected across the high-voltage charging circuit, and the low-voltage storage battery is connected across the low-voltage charging circuit; as shown in the figure, the positive electrode end and the negative electrode end of the high-voltage power battery are connected with a field effect tube Q 13 and a freewheeling diode D1, the positive electrode end of the high-voltage power battery is connected with the field effect tube Q 13 through a switch N4, the connection point of the positive electrode end of the high-voltage power battery and the field effect tube Q 13 is a point g, the connection point of the switch N2 and the field effect tube Q 11 is a point h, a switch N5 is arranged between the point g and the point h, and the low-voltage storage battery is connected across the maintaining capacitor C2.

[0073] Based on the integrated system of the electric vehicle on-board charging and the driving motor according to the embodiment of the present application, in a specific embodiment, a working method of the integrated system of the electric vehicle on-board charging and the driving motor is provided, the working method comprises a charging mode, a driving mode, an electric energy feedback mode, a braking energy feedback mode and a fault-tolerant mode, and different working modes meet different requirements of the electric vehicle.

[0074] The charging mode is used to realize the charging function of the high-voltage power battery and / or the low-voltage storage battery, and according to the source of the electric energy, the charging mode is divided into a three-phase alternating current input mode, a single-phase alternating current input mode, a direct current input mode and a vehicle-mounted photovoltaic charging mode;

[0075] As shown in the figure, Figure 2 in the three-phase alternating current input mode, the switch K3 is closed, the switch K4 and the switch K5 are disconnected, three ports of the first port group in the switch unit are connected with three ports of the second port group in correspondence, that is, the port N 6a is connected with the port N 7a , the port N 6b is connected with the port N 7b , the port N 6c is connected with the port N 7c , and three-phase alternating current is input from the U a , U b , U c port, at this time, the S1-S4 bridge arm, the S3-S6 bridge arm and the S5-S2 bridge arm constitute a three-phase six-switch power factor correction circuit, the on-off of the silicon carbide field effect tube S1 to S6 is controlled, so that the phase of the input current is the same as that of the input voltage, the waveform is approximately sinusoidal, and the purpose of power factor correction is achieved.

[0076] As shown in the figure, Figure 3 in the single-phase alternating current input mode, the switch K3 is closed, the switch K4 and the switch K5 are disconnected, two ports of the first port group of the switch unit are connected with two ports of the second port group, as shown in the figure, the port N 6aand port N 7a connection, port N 6b and port N 7b connection, single-phase alternating current from U a , U b Port input, at this time S1-S4 bridge arm, S3-S6 bridge arm constitutes a single-phase power factor correction circuit, by controlling S1, S3, S4, S6 on-off makes the input voltage and current in phase, to achieve the purpose of power factor correction.

[0077] As Figure 4 shown, in the DC input mode, switch K2 is closed, so that the DC source is connected, at this time, the DC bus capacitor C dc provides stable high-voltage DC power for the latter stage.

[0078] As Figure 5 shown, in the vehicle-mounted photovoltaic input mode, switch K1 is closed, so that the vehicle-mounted photovoltaic charging circuit is connected, at this time, the vehicle-mounted photovoltaic panel converts sunlight into DC power, and the DC / DC converter outputs stable DC voltage.

[0079] In the above input mode, the charging mode includes a parking charging mode and a driving charging mode, and the parking charging mode includes a parking high-voltage charging mode and a parking low-voltage charging mode.

[0080] As Figure 6 shown, in the parking high-voltage charging mode, the power input mode can adopt the above-mentioned three-phase alternating current input mode and DC input mode, and in the charging process, switches N1, N4 and N5 are closed, at this time, the Q1-Q2 bridge arm, Q3-Q4 bridge arm and Q5-Q6 bridge arm of the primary three-phase circuit are all turned on, the Q7-Q8 bridge arm, Q9-Q 10 bridge arm and Q 11 -Q 12 bridge arm of the high-voltage charging circuit are all turned on, and the primary three-phase circuit, transformer T1, transformer T2, transformer T3 and high-voltage charging circuit constitute a three-phase CLLC bidirectional DC-DC resonant converter, which raises the DC bus voltage to the required voltage to charge the power battery.

[0081] As Figure 7As shown, in the parking low-voltage charging mode, the power input mode adopts a single-phase AC input mode. Switches N2 and N3 are closed, and switch N5 is open, disconnecting the high-voltage power battery from the high-voltage charging circuit and connecting the low-voltage charging circuit. This connects the low-voltage battery to the low-voltage charging circuit, and the Q1-Q2 and Q3-Q4 bridge arms of the primary three-phase circuit are connected. The third secondary resonant circuit of the high-voltage input circuit is disconnected. At this time, the primary three-phase circuit, transformers T1 and T2, and the high-voltage charging circuit constitute a two-phase CLLC bidirectional DC-DC resonant circuit. However, since the input voltage is still relatively high in the single-phase AC input mode, in order to reduce the input voltage to the usable voltage of the low-voltage battery, the field-effect transistor Q... 13 A single-stage buck chopper circuit consisting of freewheeling diode D1, filter inductor L4, and holding capacitor C1, and Q... 11 -Q 12 The two-stage step-down chopper circuit, composed of the bridge, filter inductor L5, and holding capacitor C2, charges the low-voltage battery after two-stage step-down regulation.

[0082] Since the low-voltage battery continuously supplies power to the vehicle's low-voltage electrical equipment while the vehicle is in motion, the charging of the low-voltage battery during vehicle operation needs to be considered. The driving charging modes include a driving low-voltage charging mode and a driving power battery charging mode.

[0083] like Figure 8 As shown, the power source for the vehicle's low-voltage photovoltaic charging mode is photovoltaic input mode. Due to the special requirements of the photovoltaic power generation system, the vehicle's low-voltage photovoltaic charging mode can only be used when there is sunlight. In the vehicle's low-voltage photovoltaic charging mode, switches K1 and N3 are closed. Since the voltage level of the power generated by the photovoltaic circuit is relatively low, the low-voltage charging circuit utilizes the field-effect transistor Q. 11 Q 12 The two-stage buck chopper circuit, consisting of filter inductor L5 and holding capacitor C2, reduces the voltage input to the photovoltaic input circuit to charge the low-voltage battery.

[0084] like Figure 9 As shown, in the vehicle's power battery charging mode, switches N2, N3, and N4 are closed, and switch N5 is open. At this time, the field-effect transistor Q... 13 When the freewheeling diode D1, filter inductor L4, and holding capacitor C1 form a first-stage step-down chopper circuit, Q is turned on. 11 -Q 12 The bridge, filter inductor L5, and holding capacitor C2 form a two-stage step-down chopper circuit. During driving, the high-voltage DC power from the high-voltage power battery charges the low-voltage battery after being stepped down and regulated by the two stages.

[0085] The driving modes include a three-phase motor driving mode, a single-phase motor driving mode and a direct current motor driving mode. In the driving modes, the low-voltage charging circuit is disconnected, the high-voltage charging circuit is connected with the high-voltage power battery, the electric energy of the high-voltage power battery is lifted to the DC bus voltage through the primary three-phase circuit and the high-voltage charging circuit to form a three-phase CLLC bidirectional DC-DC resonant converter, the DC bus voltage drives a direct current motor, and the DC bus voltage is converted into an alternating current through the power factor correction circuit working in an inverting state to drive the three-phase motor or the single-phase motor to meet different driving needs.

[0086] As shown in Figure 10 , in the three-phase motor driving mode, the switches N1, N4 and N5 are closed, the first port group in the switch unit is connected with the second port group, i.e. the port N 6a is connected with the port N 7a , the port N 6b is connected with the port N 7b , and the port N 6c is connected with the port N 7c , at this time, the S1-S4 bridge arm, the S3-S6 bridge arm and the S5-S2 bridge arm form a three-phase six-switch power factor correction circuit, the primary three-phase circuit and the high-voltage charging circuit form a three-phase CLLC bidirectional DC-DC resonant converter to lift the electric energy in the power battery to the DC bus voltage, the field effect tubes S1 to S6 are adjusted to make the power factor correction circuit work in a three-phase inverting state to invert the DC bus voltage into a three-phase alternating current to drive the three-phase motor.

[0087] As shown in Figure 11 , in the single-phase motor driving mode, the switches K5, N1 and N4 are closed, the port N 6b and the port N 6c in the first port group in the switch unit are respectively connected with the port N 7a and the port N 7b in the second port group to make the single-phase motor connected with the power factor correction circuit, in this working mode, the primary three-phase circuit and the high-voltage charging circuit form a three-phase CLLC bidirectional DC-DC resonant converter to lift the electric energy in the power battery to the DC bus voltage, the trigger pulses of the field effect tube S5 and the field effect tube S2 in the power factor correction circuit are blocked, and the field effect tube S1, the field effect tube S4, the field effect tube S3 and the field effect tube S6 work in a single-phase inverting state to invert the DC bus voltage into a single-phase alternating current to drive the single-phase motor.

[0088] As shown in Figure 12 , in the direct current motor driving mode, the switches K6, N1, N4 and N5 are closed to make the direct current motor connected with the DC bus capacitor C dcAt both ends, in this operating mode, the primary three-phase circuit and the high-voltage charging circuit form a three-phase CLLC bidirectional DC-DC resonant converter. By changing the field-effect transistor Q7 to the field-effect transistor Q... 12 The switching frequency of the power battery is adjusted to boost the electrical energy in the power battery to the required DC bus voltage, thereby driving the DC motor.

[0089] During the use of electric vehicles, the electrical energy in the high-voltage power battery can be transmitted to the AC transmission circuit and DC transmission circuit through the power feedback method, and then the AC or DC power can be output for other needs. The power feedback mode includes grid-connected mode, DC feedback mode and single-phase feedback mode.

[0090] like Figure 13 As shown, the grid-connected mode is used to enable energy to flow from the high-voltage power battery of the electric vehicle to the grid side. In this mode, switches K3, N1, N4, and N5 are closed, and port N of the switching unit is closed. 6a With port N 7a Connection, Port N 6b With port N 7b Connection, Port N 6c With port N 7c The three-phase power grid is connected, and the primary three-phase circuit and the high-voltage charging circuit form a three-phase CLLC bidirectional DC-DC resonant converter, which boosts the electrical energy in the power battery to the DC bus voltage. At this time, the power factor correction circuit works in the inverter state, converting the DC power into AC power with the same amplitude and phase as the power grid, and feeding energy back to the power grid side.

[0091] like Figure 14 As shown, the DC feedback mode is used to output DC power to provide DC power to external devices. For example, when other electric vehicles need emergency charging, DC power can be output in this working mode to provide DC power to other electric vehicles, realizing the rescue of electric vehicles that have broken down due to insufficient power. In this mode, switches N1, N4, N5, and K2 are closed, and the primary three-phase circuit and the high-voltage charging circuit form a three-phase CLLC bidirectional DC-DC resonant converter, which boosts the electrical energy in the power battery to the DC bus voltage and outputs DC power through the DC transmission circuit.

[0092] like Figure 15 As shown, the single-phase feedback mode outputs single-phase AC power to provide power to single-phase AC appliances in emergency environments such as outdoors. In this mode, switches N1, N4, N5, and K3 are closed, and port N of the switching unit... 6a With port N 7b Connection, port N 6b With port N 7cThe three-phase primary circuit and the high-voltage charging circuit are connected to form a three-phase CLLC bidirectional DC-DC resonant converter, which boosts the electrical energy in the power battery to the DC bus voltage. The power factor correction circuit works in single-phase inverter mode, converting DC power into 220V single-phase AC power, which is then output through the single-phase transmission circuit.

[0093] When the motor is working or braking, it generates reverse braking torque and back electromotive force. The system can use energy feedback mode to feed energy back to the high-voltage power battery or low-voltage storage battery according to the magnitude of the back electromotive force generated by the motor braking.

[0094] Three-phase motors, single-phase motors, and DC motors can all generate back electromotive force during braking. Taking a three-phase motor as an example, we will analyze the energy feedback mode, such as... Figure 16 As shown, in energy feedback mode, when charging the high-voltage power battery, and feeding the motor's braking energy back to the high-voltage power battery, switches K4, N1, N4, and N5 are closed, and port N in the switching unit... 6a and port N 7a Connection, port N 6b and port N 7b Port N 6c and port N 7c Connect and adjust MOSFETs S1 to S6 to enable the power factor correction circuit to operate in rectification mode, converting the electrical energy generated during the braking process of the three-phase motor into high-voltage DC power. The primary three-phase circuit and the high-voltage charging circuit form a three-phase CLLC bidirectional DC-DC resonant converter, converting the DC bus voltage to the required voltage to charge the power battery. The braking energy recovery mode of single-phase motors and DC motors is similar to that of three-phase motors and will not be described further here.

[0095] like Figure 17 As shown, when charging the low-voltage battery in energy feedback mode, switches K4, N2, and N3 are closed, and port N of the switching unit is closed. 6a and port N 7a Connection, port N 6b and port N 7b Connection, port N 6c and port N 7c When connected, the power factor correction circuit operates in rectification mode, converting the electrical energy generated during the braking process of the three-phase motor into high-voltage DC power. Since the battery voltage level is relatively low, the input voltage can be stepped down three times before the battery is charged. At this time, the primary three-phase circuit and the high-voltage charging circuit form a two-phase CLLC bidirectional DC-DC resonant converter to step down the input voltage once. The two-stage cascaded step-down chopper circuit of the low-voltage charging circuit steps down the input voltage twice, thereby realizing the charging of the low-voltage battery.

[0096] The field effect tube failure can cause any bridge arm of the power factor correction circuit, the primary side three-phase circuit or the high voltage charging circuit to fail, in order to make the failure not affect the normal operation of the above various working modes, the working method of the application includes a fault tolerance mode, which can also make the integrated system of the application keep normal operation when the field effect tube fails, the fault tolerance mode includes a power factor correction circuit fault tolerance mode and a primary side three-phase electric circuit fault mode and a high voltage charging circuit fault mode, the power factor correction circuit fault tolerance mode includes a three-phase state fault tolerance mode and a single-phase state fault tolerance mode;

[0097] When the power factor correction circuit works in three phases, if one bridge arm in the power factor correction circuit fails, the three-phase state fault tolerance mode is adopted, for example, as shown in the figure, Figure 18 When the S5-S2 bridge arm fails, in this mode, the port N 7c in the switch unit is switched to any one of the port N 8a , the port N 8b or the port N 8c When it is switched to the N 8b connection, then the S1-S4 bridge arm, the S3-S6 bridge arm and the Q3-Q4 bridge arm form a new power factor correction circuit, at this time, the primary side three-phase circuit and the high voltage charging circuit form a two-phase CLLC bidirectional DC-DC resonant converter.

[0098] When the power factor correction circuit works in single phase, at most two bridge arms can fail, when a bridge arm fails, the single-phase fault tolerance mode is adopted. When a bridge arm of the power factor correction circuit fails, the remaining two ports of the second port group are turned on, for example, as shown in the figure, Figure 19 When the S1-S4 bridge arm fails, in this mode, the N 7a in the switch unit is switched to the port N 7c , that is, the port N 7b and the port N 7c are turned on, and the S3-S6 bridge arm and the S5-S2 bridge arm form a new power factor correction circuit, as shown in the figure. Figure 19

[0099] When any two bridge arms of the power factor correction circuit fail, the remaining one port in the second port group and any port in the third port group are turned on, so that the remaining one bridge arm of the power factor correction circuit and one bridge arm in the primary side three-phase circuit form a new single-phase power factor correction circuit, for example, when the S1-S4 bridge arm and the S3-S6 bridge arm fail, the port N 7a and the port N 7b in the switch unit are disconnected, and the port N 8a , the port N 8b and the port N 8c ​If any port is connected, such as Figure 20 As shown, when switching to port N 8a When connected, the S5-S2 bridge arm and Q1-Q2 bridge arm of the field effect transistor form a new single-phase power factor correction circuit. At this time, the primary three-phase circuit and the high-voltage charging circuit are transformed from a three-phase CLLC bidirectional DC-DC resonant converter to a two-phase CLLC bidirectional DC-DC resonant converter.

[0100] In the primary-side three-phase circuit fault mode, the trigger pulse of the faulty bridge arm is blocked, and the bridge arm corresponding to the faulty bridge arm in the high-voltage charging circuit is also blocked. In the high-voltage charging circuit fault mode, the trigger pulse of the faulty bridge arm is blocked, and the bridge arm corresponding to the faulty bridge arm in the primary-side three-phase circuit is also blocked. The three-phase CLLC bidirectional DC-DC resonant converter is converted into a two-phase CLLC bidirectional DC-DC resonant converter to ensure the normal operation of the system.

[0101] Since the power devices in various modes are the same, only the power flow direction is different, such as Figure 21 As shown, taking a fault in bridge arm Q3-Q4 as an example, when bridge arm Q3-Q4 fails, bridge arm Q3-Q4 and the corresponding Q9-Q in the high-voltage charging circuit are blocked. 10 When the bridge arm triggers a pulse, a fault in the primary three-phase circuit or the high-voltage charging circuit will cause a two-phase CLLC bidirectional DC-DC resonant converter to be formed.

[0102] This invention achieves system integration and bidirectional operation of power devices while meeting diverse operating conditions and adapting to different environments, effectively reducing costs. By effectively combining the motor drive system with the on-board charger, this invention increases the overall power density of both and reduces their overall size. Therefore, the integrated on-board charging and motor control solution for electric vehicles of this invention will be the optimal choice for electric vehicles and will become an important direction for the development of the electric vehicle industry.

[0103] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. An integrated system of on-board charging of an electric vehicle and a drive motor, characterized in that, The system comprises: a switch unit comprising a first port group, a second port group and a third port group, the first port group comprising at least three ports, the second port group comprising at least three ports, and the third port group comprising at least three ports; an energy conversion unit comprising a power factor correction circuit, a DC bus capacitor, a primary side three-phase circuit, a transformer, a high-voltage charging circuit and a low-voltage charging circuit, the second port group of the switch unit being connected to the power factor correction circuit, and the third port group of the switch unit being connected to the primary side three-phase circuit; The high-voltage charging circuit includes three bridge arms with identical structures connected in parallel. The three bridge arms are the Q7-Q8 bridge arm composed of field-effect transistors Q7 and Q8, the bridge arm composed of field-effect transistors Q9 and Q8, and the bridge arm composed of field-effect transistors Q9 and Q8. 10 The Q9-Q structure 10 Bridge arm and Q-type field-effect transistor 11 and field-effect transistor Q 12 The Q constituting 11 -Q 12 Bridge arm; the low-voltage charging circuit includes a first-stage buck chopper circuit and a low-voltage resonant circuit, the low-voltage resonant circuit being connected in parallel across a field-effect transistor in the third bridge arm; the first-stage buck chopper circuit includes a field-effect transistor Q. 13 Freewheeling diode D1, filter inductor L4 and sustaining capacitor C1, field-effect transistor Q 13 After being connected in series with the freewheeling diode D1, it is connected in parallel to Q9-Q. 10 At both ends of the bridge arm, the two ends of the holding capacitor C1 are connected in parallel to Q. 11 -Q 12 At both ends of the bridge arm, the sustaining capacitor C1 and the field-effect transistor Q 11 A switch N2 is provided between them, and one end of the filter inductor L4 is connected to the field-effect transistor Q. 13 Between the freewheeling diode D1 and the filter inductor L4, the other end is connected between the sustaining capacitor C1 and the switch N2; the low-voltage resonant circuit includes a filter inductor L5 and a sustaining capacitor C2, which are connected in series and then in parallel to the field-effect transistor Q. 12 At both ends, the filter inductor L5 and the field-effect transistor Q 12 A switch N3 is installed between them; an input unit comprising an AC transmission circuit, a DC transmission circuit and a photovoltaic input circuit, the AC transmission circuit being connected to the first port group through a switch K3, the DC transmission circuit being connected across the DC bus capacitor through a switch K2, and the photovoltaic input circuit being connected to the low-voltage charging circuit through a switch K1; The battery unit comprises a high-voltage power battery and a low-voltage storage battery, the high-voltage power battery is connected at two ends of a high-voltage charging circuit, and the low-voltage storage battery is connected at two ends of a low-voltage charging circuit; a positive electrode end of the high-voltage power battery is connected with a connection point g of a field effect tube Q 13 , a connection point between a switch N2 and the field effect tube Q 11 is a connection point h, and a switch N5 is arranged between the connection point g and the connection point h. a motor unit comprising a three-phase motor, a single-phase motor and a DC motor, the three-phase motor being connected to the first port group through a switch K4, the single-phase motor being connected to the first port group through a switch K5, and the DC motor being connected across the DC bus capacitor through a switch K6.

2. The integrated system for charging and driving electric vehicle motors as claimed in claim 1 wherein, The power factor correction circuit comprises three parallel bridge arms, each bridge arm comprising two field effect transistors connected in series, and the three ports of the second port group of the switch unit being connected to the midpoints of the three bridge arms of the power factor correction circuit, respectively; and the primary side three-phase circuit comprises three parallel bridge arms, each bridge arm comprising two field effect transistors connected in series, and the three ports of the third port group of the switch unit being connected to the midpoints of the three bridge arms of the primary side three-phase circuit, respectively.

3. Method of operation of an integrated system of on-board charging of an electric vehicle and drive motor, characterised in that, The integrated system for charging and driving a motor of an electric vehicle based on the system of claim 2, wherein the working method comprises a charging mode and a fault-tolerant mode; the charging mode comprises a parking charging mode, and the parking charging mode comprises a parking high-voltage charging mode and a parking low-voltage charging mode; in the parking high-voltage charging mode, the low-voltage charging circuit is disconnected, the primary side three-phase circuit and the high-voltage charging circuit form a three-phase CLLC bidirectional DC-DC resonant converter to charge the high-voltage power battery; in the parking low-voltage charging mode, the high-voltage power battery is disconnected from the high-voltage charging circuit, the primary side three-phase circuit and the high-voltage charging circuit are connected to form a two-phase CLLC bidirectional DC-DC resonant converter, the third bridge arm of the high-voltage charging circuit and the low-voltage resonant circuit of the low-voltage charging circuit form a secondary voltage reduction chopper circuit, and the DC bus voltage is regulated by the primary voltage reduction chopper circuit and the secondary voltage reduction chopper circuit to charge the low-voltage storage battery; the fault-tolerant mode comprises a power factor correction circuit fault-tolerant mode, a primary side three-phase circuit fault mode and a high-voltage charging circuit fault mode, and the power factor correction circuit fault-tolerant mode comprises a three-phase state fault-tolerant mode and a single-phase state fault-tolerant mode. In the three-phase fault-tolerant mode, when a bridge arm of the power factor correction circuit fails, any port in the third port group is turned on, so that the remaining two bridge arms of the power factor correction circuit and one bridge arm in the primary three-phase circuit form a three-phase power factor correction circuit, and the remaining two bridge arms in the primary three-phase circuit and the high-voltage charging circuit form a two-phase CLLC bidirectional DC-DC resonant converter; In the single-phase fault-tolerant mode, when a bridge arm of the power factor correction circuit fails, the remaining two ports of the second port group are turned on; when any two bridge arms of the power factor correction circuit fail, the remaining one port of the second port group and any port of the third port group are turned on, so that the remaining one bridge arm of the power factor correction circuit and one bridge arm in the primary three-phase circuit form a single-phase power factor correction circuit, and the remaining two bridge arms in the primary three-phase circuit and the high-voltage charging circuit form a two-phase CLLC bidirectional DC-DC resonant converter; In the primary three-phase circuit fault mode, the trigger pulse of the fault bridge arm is blocked, and the bridge arm corresponding to the fault bridge arm in the high-voltage charging circuit is also blocked; In the high-voltage charging circuit fault mode, the trigger pulse of the fault bridge arm is blocked, and the bridge arm corresponding to the fault bridge arm in the primary three-phase circuit is also blocked.

4. The method of claim 3, wherein the method further comprises: The charging mode includes a driving charging mode, and the driving charging mode includes a driving low-voltage charging mode and a driving power battery low-voltage charging mode; In the driving low-voltage charging mode, the first-stage voltage reduction chopper circuit is disconnected, the photovoltaic input circuit is connected to the second-stage voltage reduction chopper circuit, and the low-voltage storage battery is charged. In the driving power battery low-voltage charging mode, the high-voltage power battery is connected to the first-stage voltage reduction chopper circuit and the second-stage voltage reduction chopper circuit, and the low-voltage storage battery is charged.

5. The method of claim 3, wherein the method further comprises: The working method includes a driving mode, in which the low-voltage charging circuit is disconnected, the high-voltage charging circuit is connected to the high-voltage power battery, the electric energy of the high-voltage power battery is boosted to a DC bus voltage through the three-phase CLLC bidirectional DC-DC resonant converter formed by the primary three-phase circuit and the high-voltage charging circuit, the DC bus voltage drives a DC motor, and the DC bus voltage is converted into AC power through the power factor correction circuit working in the inverter state, so as to drive a three-phase motor or a single-phase motor.

6. The method of claim 3, wherein the method further comprises: The working method includes an electric energy feedback mode, in which the low-voltage charging circuit is disconnected, the high-voltage charging circuit is connected to the high-voltage power battery, the electric energy of the high-voltage power battery is boosted to a DC bus voltage through the three-phase CLLC bidirectional DC-DC resonant converter formed by the primary three-phase circuit and the high-voltage charging circuit, and the DC bus voltage is output through a DC transmission circuit; the DC bus voltage is converted into AC power through the power factor correction circuit working in the inverter state, and the AC power is output through an AC transmission circuit.

7. The method of claim 3, wherein the method further comprises: The working method comprises a braking energy feedback mode, in the energy feedback mode, the power factor correction circuit works in a rectification state, converts the electric energy generated in the motor unit braking process into high-voltage direct current, and the primary three-phase circuit and the high-voltage charging circuit constitute a CLLC bidirectional direct-current-direct-current resonant converter to convert the high-voltage direct current into the voltage required by the high-voltage power battery or the low-voltage storage battery for charging the high-voltage power battery or the low-voltage storage battery.

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