CN210970634U

CN210970634U - Integrated electric drive system and electric vehicle comprising same

Info

Publication number: CN210970634U
Application number: CN201921307428.5U
Authority: CN
Inventors: 鲍博
Original assignee: Vitesco Technologies Holding China Co Ltd
Current assignee: Vitesco Automotive Tianjin Co Ltd
Priority date: 2019-08-13
Filing date: 2019-08-13
Publication date: 2020-07-10
Anticipated expiration: 2029-08-13

Abstract

The utility model relates to an integrated form electric drive system, include: a motor; an energy storage unit; a first conversion unit configured to convert alternating current generated when regenerative feedback is given from a power supply outside the vehicle or the motor into direct current, or convert direct current from the energy storage unit into alternating current; a second conversion unit configured to perform a step-up or step-down operation on the direct current from the first conversion unit or the energy storage unit; a third conversion unit configured to perform a conversion operation on the direct current from the second conversion unit or the energy storage unit, the third conversion unit including an inverter, first and second isolation transformers, and first and second rectifiers; and the control unit is configured to selectively control the modules so as to realize different working modes of the system. The utility model discloses still relate to an electric vehicle including this system. The system and the vehicle realize the multiplexing of power electronic devices; the manufacturing cost of the vehicle is reduced.

Description

Integrated electric drive system and electric vehicle comprising same

Technical Field

The utility model relates to an electric vehicle field, more specifically, the utility model relates to an electric vehicle that is arranged in integrated form electric drive system among the electric vehicle and includes this system.

Background

Driven by the dual pressures of energy crisis and environmental pollution, electric vehicles (and/or hybrid vehicles) are becoming a major trend in the future. Generally, an electric vehicle includes a rechargeable high-voltage battery, a three-phase motor that drives the vehicle to run using power supplied from the high-voltage battery, and an inverter for driving the motor by the high-voltage battery.

When the remaining power (SOC) of the high-voltage battery is too low, the high-voltage battery needs to be charged by a charger equipped in the vehicle, which is usually an ac charger that charges by external single-phase ac power or three-phase ac power.

In addition, an additional DC/DC converter is required to be installed to supply power to a 12V battery, which can supply power to low-voltage devices such as audio, windows, and lamps in a vehicle.

In the existing electric vehicle, an inverter, a charger, a DC/DC converter and the like used in the charging process and the driving process are respectively and independently installed on the vehicle, and the use scene is single, which not only increases the complexity of the circuit and the manufacturing cost of the vehicle, but also causes the waste of power electronic devices.

SUMMERY OF THE UTILITY MODEL

In order to solve the above problems in the prior art, the present invention provides an integrated electric drive system for a vehicle, which integrates a charger, an inverter, a motor and a DC/DC converter, realizes multiplexing of power electronic devices, and can simultaneously support two-phase and three-phase ac charging and DC charging; in addition, the system cancels a separate charger, an inverter and a direct current converter, reduces the fixed load of the vehicle and reduces the manufacturing cost of the vehicle.

Specifically, the utility model provides an integrated form electric drive system, this system includes: a motor configured to drive the vehicle to run by an energy storage unit of the vehicle or to charge the energy storage unit of the vehicle by a power supply external to the vehicle or regenerative feedback energy of the motor under the control of the control unit; an energy storage unit configured to be charged with electric power of a power supply external to the vehicle or to drive the vehicle to run by the motor or to supply power to an in-vehicle load under the control of the control unit; a first conversion unit configured to convert alternating current generated at the time of regenerative feedback from a power supply external to the vehicle or the motor into direct current or convert direct current from the energy storage unit into alternating current under the control of the control unit; a second conversion unit configured to perform a step-up or step-down operation on the direct current from the first conversion unit or the energy storage unit under the control of a control unit; a third converting unit configured to convert the direct current from the second converting unit into direct current for charging the energy storing unit or convert the direct current from the energy storing unit into low-voltage direct current under the control of the control unit; and a control unit configured to selectively control a vehicle external power source, the motor, the first conversion unit, the second conversion unit, the inverter, the first isolation transformer, the second isolation transformer, the first rectifier, the second rectifier, and the energy storage unit to implement different operating modes of the system,

wherein the third conversion unit includes: an inverter configured to convert direct current from the high-voltage battery in the second conversion unit or the energy storage unit into alternating current; a first isolation transformer configured to perform a first isolation transforming operation on the alternating current from the inverter; a first rectifier configured to convert alternating current from the first isolation transformer to direct current for charging a high voltage battery in the energy storage unit; a second isolation transformer configured to perform a second isolation transforming operation on the alternating current from the inverter; and a second rectifier configured to convert the alternating current from the second isolation transformer to direct current for charging a low voltage battery in the energy storage unit.

Wherein the different operating modes of the system include one or more of driving a motor with the energy storage unit, charging a low voltage battery in the energy storage unit with a high voltage battery in the energy storage unit, charging the energy storage unit with a vehicle external power source, and charging a high voltage battery in the energy storage unit with motor regenerative feedback energy.

Wherein the electric machine comprises a plurality of coil inductances, each coil inductance having a first end connected to a vehicle external power source by means of a first switch and to a neutral point by means of a second switch, a second end connected to an alternating current end of the first conversion unit, and the control unit is configured to selectively control the switching of the first and second switches in different operating modes of the system.

Wherein the energy storage unit includes a high voltage battery for driving the motor and a low voltage battery for supplying power to low voltage devices in the vehicle.

Wherein the first conversion unit comprises six semiconductor switch tubes, and the control unit is configured to selectively control the on-off of the six semiconductor switch tubes in different operation modes of the system.

The second conversion unit comprises two semiconductor switching tubes and a choke inductor, a freewheeling diode is connected in parallel to two ends of the inductor, and the control unit is configured to selectively control the on and off of the two semiconductor switching tubes in different operation modes of the system.

The system further comprises: a third switch connected between a direct current terminal of the first conversion unit and a first terminal of the second conversion unit; a fourth switch connected between the second terminal of the second conversion unit and the input terminal of the third conversion unit; a fifth switch connected between a dc terminal of the first conversion unit and a second terminal of the second conversion unit; and a sixth switch connected between the first terminal of the second conversion unit and the input terminal of the third conversion unit, wherein the control unit is configured to selectively control on/off of the third, fourth, fifth, and sixth switches so that the second conversion unit performs a step-up or step-down operation on the direct current from the high-voltage battery of the first conversion unit or the energy storage unit, wherein the control unit is configured to open the second, third, and fourth switches and close the first, fifth, and sixth switches so that the vehicle external power supply is stepped down for charging the energy storage unit; or the control unit is configured to open the second switch, the fifth switch and the sixth switch and close the first switch, the third switch and the fourth switch, so that the vehicle external power supply is used for charging the energy storage unit after being boosted.

Wherein the inverter includes four semiconductor switching tubes, the first and second isolation transformers are connected in parallel to an output terminal of the inverter, and the first rectifier includes two semiconductor switching tubes and two diodes, an input terminal of the first rectifier is connected to the first isolation transformer, and an output terminal thereof is connected to a high voltage battery of the energy storage unit; the second rectifier comprises two semiconductor switching tubes and two diodes, the input end of the second rectifier is connected to the second isolation transformer, and the output end of the second rectifier is connected to the low-voltage battery of the energy storage unit.

The system further comprises: and a seventh switch connected between the dc terminal of the first conversion unit and the high-voltage battery of the energy storage unit, wherein the control unit is configured to selectively control on/off of the first to seventh switches to implement different operation modes of the system, wherein the control unit is configured to close the second and seventh switches and open the first, third and fifth switches to charge the high-voltage battery of the energy storage unit by driving the motor with the high-voltage battery of the energy storage unit or by regenerating feedback energy with the motor.

The system further comprises: and an eighth switch connected between the high-voltage battery of the energy storage unit and the input terminal of the third conversion unit, wherein the control unit is configured to selectively control the on/off of the first to eighth switches to realize different operation modes of the system, and wherein the control unit is configured to close the eighth switch and open the fourth and sixth switches to charge the low-voltage battery of the energy storage unit by means of the high-voltage battery of the energy storage unit.

Wherein the control unit selectively controls charging of the high voltage battery of the energy storage unit or the low voltage battery of the energy storage unit in accordance with states of charge of the high voltage battery of the energy storage unit and the low voltage battery of the energy storage unit.

The system further comprises a first L C filter connected in parallel to the output end of the first rectifier and used for filtering harmonic waves in the output signal of the first rectifier, a second L C filter connected in parallel to the output end of the second rectifier and used for filtering harmonic waves in the output signal of the second rectifier, a first filter capacitor connected in parallel to the direct current end of the first conversion unit and used for filtering harmonic waves in the direct current end signal of the first conversion unit, and/or a second filter capacitor connected in parallel to the input end of the third conversion unit and used for filtering harmonic waves in the input signal of the third conversion unit.

The first to eighth switches are controlled switches or semiconductor switches, the semiconductor switch tubes are field effect transistors or insulated gate bipolar transistors, and a freewheeling diode is connected in parallel to each semiconductor switch tube.

The utility model also provides an electric vehicle, it includes the above integrated form electric drive system.

Drawings

Fig. 1 shows a schematic block diagram of an integrated electric drive system for a vehicle according to the present invention; and

fig. 2 shows a circuit diagram of the integrated electric drive system shown in fig. 1.

Detailed Description

An integrated electric drive system according to the invention will be described below by way of example with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention to those skilled in the art. It will be apparent, however, to one skilled in the art that the present invention may be practiced without some of these specific details. Rather, any combination of the following features and elements, whether related to different embodiments or not, is contemplated to implement the present invention. Thus, the following aspects, features, embodiments and advantages are merely illustrative and should not be considered elements or limitations of the claims except where explicitly recited in a claim(s).

Fig. 1 shows a schematic block diagram of an integrated electric drive system for a vehicle according to the invention, and fig. 2 shows a circuit diagram of the integrated electric drive system shown in fig. 1. As shown in fig. 1 and 2, the system 10 includes a control unit 11, a motor 12, a traction power conversion unit 13, a bidirectional buck-boost conversion unit 14, a charge conversion unit, and an energy storage unit.

The energy storage unit comprises a high-voltage battery 18 and a low-voltage battery 19, the high-voltage battery 18 being configured to supply power to the electric machine 12 to cause it to rotate the wheels, and therefore also referred to as "power battery"; the low-voltage battery 19 refers to a 12V storage battery in the vehicle, which is configured to supply power to low-voltage devices in the vehicle. The "vehicle" referred to herein includes electric vehicles and hybrid vehicles. The functions of the various modules in the system and their connections are described in detail below.

The electric machine 12 rotates wheels by means of the machine output member 110, is configured as a permanent magnet/AC induction machine, and comprises an induction unit 121 consisting of a plurality of induction coils, as shown in fig. 2, the induction unit 121 is composed of three-phase windings (inductances L1, L2, L03), in the driving mode the inductances L11, L22, L33 are configured as induction coils, serving to excite an externally input alternating current, the inductances L41, L2, L3 are connected at one end to the traction power conversion unit 13 and at the other end to a neutral point, to drive the vehicle motor in rotation by means of power from a high voltage battery, in the charging mode the inductances L1, L2, L3 are configured as filter inductances, serving to filter the externally input alternating current, wherein the inductances L1, L2, L3 open the neutral point by means of switches S4, S5, S6, respectively, and are connected to an external grid by means of further switches S1, S2, S3, S673, to store energy in the external grid, to act as an example of a regenerative generator, to generate a regenerative energy in the charging mode, which the vehicle motor, and to generate a regenerative energy, for example, a regenerative power generation.

The traction power conversion unit 13 is a bidirectional DC/AC converter including a plurality of semiconductor switching tubes Q1-Q6. the AC terminal of the traction power conversion unit 13 is connected to the inductances L1, L2, L3 of the electric machine 12, and the DC terminal is connected to the high voltage battery 18 via a switch S7, which is configured to convert AC power from the electric machine (in the case where regenerative feedback occurs) or an external grid into DC power for charging the energy storage unit (i.e., "charging mode" when the traction power conversion unit 13 functions as a rectifier) or convert DC power from the energy storage unit into AC power for driving the electric machine (i.e., "driving mode" when the traction power conversion unit 13 functions as an inverter) under the control of the control unit 11.

The bidirectional buck-boost conversion unit 14 is a DC/DC converter, and is composed of two semiconductor switching tubes Q13, Q14 and a choke inductor L5, the bidirectional buck-boost conversion unit 14 is connected to the DC terminal of the traction power conversion unit 13 through a switch 2PS1 or 3PS3, and is connected to the charging conversion unit through a switch 2PS2 or 3PS4, and further is connected to the high-voltage battery 18 through a switch S8, so as to perform a boost or buck operation on the DC voltage converted by the traction power conversion unit 13 or the DC voltage output by the high-voltage battery 18 by turning on and off the switches 2PS1,2PS2, 3PS3, 3PS4 and S8.

Specifically, the bidirectional buck-boost converting unit 14 performs a boost operation on the direct current from the traction power converting unit 13 when the switches 2PS1 and 2PS2 are closed and the switches 3PS3 and 3PS4 are open, or performs a buck operation on the direct current from the high-voltage battery 18 when the switch S8 is further closed; the bidirectional buck-boost conversion unit 14 performs a buck operation on the direct current from the traction power conversion unit 13 when the switches 2PS1 and 2PS2 are open and the switches 3PS3 and 3PS4 are closed, or performs a boost operation on the direct current from the high-voltage battery 18 when the switch S8 is further closed.

The charge conversion unit is connected not only to the bidirectional buck-boost conversion unit 14 by means of the switch 2PS2 or 3PS4, but also to the high-voltage battery 18 by means of the switch S8, and is configured to convert the direct current from the bidirectional buck-boost conversion unit 14 into direct current for charging the high-voltage battery 18 or the low-voltage battery 19, or convert the direct current of the high-voltage battery 18 into direct current for charging the low-voltage battery 19. The charging conversion unit specifically includes an H-bridge inverter 15, an isolation transformer module (also directly abbreviated as "transformer" herein) including a first isolation transformer 161 and a second isolation transformer 162, and a rectifier module (also directly abbreviated as "rectifier" herein) including a first rectifier 171 and a second rectifier 172, and the internal circuit structure of the charging conversion unit is explained in detail below.

The H-bridge inverter 15 is an H-bridge inverter formed by connecting four switching tubes Q7-Q10, and the input end thereof is connected to the bidirectional buck-boost converting unit 14 through a switch 2PS2 or 3PS4 and is connected to the high-voltage battery 18 through a switch S8 so as to convert the direct current from the bidirectional buck-boost converting unit 14 or from the high-voltage battery 18 into alternating current.

The input terminals of the first and second isolation transformers 161/162 are connected to the output terminal of the H-bridge inverter 15 for performing different isolation transforming operations (depending on whether the high-voltage battery or the low-voltage battery is charged) on the alternating current from the H-bridge inverter 15, respectively.

The first rectifier 171 is composed of switching tubes Q11, Q12 and diodes D1, D2, and has an input terminal connected to an output terminal of the first isolation transformer 161 for reconverting the alternating current from the first isolation transformer 161 into direct current. The output terminal of the first rectifier 171 is connected to the high voltage battery 18, and the dc power rectified by the first rectifier 171 can be used to charge the high voltage battery 18.

The second rectifier 172 is composed of switching tubes Q15, Q16 and diodes D3, D4, and has an input terminal connected to the output terminal of the second isolation transformer 162 for converting the ac power from the second isolation transformer 162 back to dc power. The output end of the second rectifier 172 is connected to the low-voltage battery 19, and the direct current rectified by the second rectifier 172 can be used for charging the low-voltage battery 19.

Preferably, between the first rectifier 171 and the high voltage battery 18 and between the second rectifier 172 and the low voltage battery 19, a control switch is provided, respectively, to gate the charging of the high voltage battery or the low voltage battery according to the different operation modes of the system. However, it will be understood by those skilled in the art that the control switch may be omitted, in which case the charging of the high-voltage battery or the low-voltage battery is achieved by controlling the conductive state of the switching tubes of the

rectifiers

172, 171. Since this content is not in the focus of the present invention, it will not be described in detail herein.

Herein, the operation mode of the integrated electric drive system for a vehicle is largely classified into two modes of "charging mode" and "driving mode". The term "driving mode" refers to that the vehicle motor is driven to run by means of the high-voltage battery of the vehicle during the running process of the vehicle; alternatively, the low-voltage battery may be charged by the vehicle high-voltage battery while the vehicle motor is driven in operation (i.e., the motor is driven and the low-voltage battery is charged by the high-voltage battery). The "charging mode" referred to herein relates to the following two cases:

-charging the low-voltage battery by means of the high-voltage battery of the vehicle in a stationary state of the vehicle (for example parked in a garage), or charging the high-voltage battery or the low-voltage battery of the vehicle by means of an external power supply, in particular comprising charging the high-voltage battery (HV) by means of a three-phase voltage, charging the high-voltage battery by means of a two-phase voltage, charging the low-voltage battery (L V) by means of a three-phase voltage, and charging the low-voltage battery by means of a two-phase voltage, and

in the event of feedback energy occurring during the driving of the vehicle, the regenerative feedback energy is used for charging the high-voltage battery of the vehicle, i.e. the high-voltage battery is charged by means of the regenerative energy. In this context, regenerative braking or regenerative braking refers to the conversion of mechanical energy from a load into electrical energy by means of an electric machine during braking or freewheeling of the vehicle and the storage of the electrical energy in a high-voltage battery, in which case the electric machine of the vehicle acts as a generator.

In different operation modes of the system, the control unit 11 can selectively turn on or off the above-mentioned switches S1-S8,2PS1,2PS2, 3PS3 and 3PS4 and the semiconductor switch transistors Q1-Q16 to control the motor 12, the traction power conversion unit 13, the bidirectional buck-boost conversion unit 14, the H-bridge inverter 15, the isolation transformer 161/162, the rectifier 171/172, the high-voltage battery 18 and the low-voltage battery 19 to perform different functions.

In the present invention, the semiconductor switch transistors Q1-Q16 may be implemented as field effect transistors (e.g., MOSFET and JFET) or Insulated Gate Bipolar Transistors (IGBT). preferably, a freewheeling diode (not shown in fig. 2) may be connected in parallel to each semiconductor switch transistor to prevent the switch transistors from being broken down by reverse voltage, and furthermore, a capacitor may be connected in parallel to the input terminals of the traction power conversion unit 13 and the charge conversion unit to filter out harmonics in the circuit.more preferably, a L C low pass filter (as shown in fig. 2) may be connected to the output terminals of the first rectifier 171 and the second rectifier 172 to filter out harmonics in the circuit.

In the drive mode, the control unit 11 controls the electric power of the high-voltage battery 18 to flow through the traction power conversion unit 13 by means of the switch S7 to be converted into alternating current for driving the motor; at the same time, the control unit 11 can also control the power of the high-voltage battery 18 to flow through the H-bridge inverter 15, the isolation transformer 162 and the rectifier 172 in order by means of the switch S8, and finally used to charge the 12V low-voltage battery 19.

In the charging mode, the control unit 11 accesses external ac power through the inductance unit 121 of the motor, rectifies the ac power into dc power through the traction power conversion unit 13, steps up or steps down the dc power through the bidirectional step-up/step-down conversion unit 14, converts the ac power into ac power through the H-bridge inverter 15, regulates the voltage through the

isolation transformer

161 or 162, and rectifies the dc power through the

rectifier

171 or 172 to charge the high-voltage battery 18 or the low-voltage battery 19 of the energy storage unit. According to a particular embodiment, in the event of regenerative energy feedback, the control unit 11 may charge the high voltage battery 18 by means of the power provided by the motor inductance unit 121 itself, in which case the power generated by the inductance unit 121 is provided directly to the high voltage battery after being rectified by the traction power conversion unit 13.

According to a preferred embodiment, the control unit 11 can control the on/off of each switch and/or switch tube in real time according to the SOC of the high-voltage battery 18 and/or the low-voltage battery 19, so as to coordinate the charging of the high-voltage battery 18 and the low-voltage battery 19. Specifically, when the SOC of the high-voltage battery 18 is lower than the first threshold value, the control unit 11 preferentially ensures charging of the high-voltage battery 18; in the case where the SOC of the high-voltage battery 18 is restored to the second threshold value (which is higher than the first threshold value), when the SOC of the low-voltage battery 19 is lower than the third threshold value, the control unit 11 stops charging of the high-voltage battery 18 while the high-voltage battery 18 charges the low-voltage battery 19 through the H-bridge inverter 15, the isolation transformer 162, and the rectifier 172.

In this context, the low-voltage battery is a 12V battery and the external power source (i.e., the "off-board power source") is 220V mains or 380V three-phase ac. As a first example, assuming that both the vehicle motor and the high voltage battery operate at a 400v voltage platform, several main operating modes of the integrated electric drive system for a vehicle according to the present invention under this platform can be described as follows.

a. Charging mode

1.1 charging high-Voltage batteries by means of three-phase Voltage

In this mode, switches S1-S3 are closed and S4-S6 are open, so that the ac power from the external grid is filtered by motor inductors L1, L2, L3 and transmitted to traction power conversion unit 13, which now consists of Q1-Q6 switching tubes, traction power conversion unit 13 operates in a rectification mode to convert the ac power from the external grid to dc power.

Further, the switches S7 and S8 are opened, the switches S1 and 2PS2 are opened, the switches 3PS3 and 3PS4 are closed, the direct current output from the traction power conversion unit 13 is input to the second end of the bidirectional buck-boost conversion unit 14, the bidirectional buck-boost conversion unit 14 performs a buck operation on the direct current output from the traction power conversion unit 13, and the buck direct current is transmitted from the first end of the bidirectional buck-boost conversion unit 14 to the H-bridge inverter 15, and the H-bridge inverter 15 converts the buck direct current back to alternating current. The ac power converted by the H-bridge inverter 15 is voltage-regulated by the first isolation transformer 161, and then transmitted to the first rectifier 171 to be converted into dc power again by the first rectifier 171, and the first rectifier 171 transmits the rectified dc power to the high-voltage battery 18 to charge the high-voltage battery.

1.2 charging a high-voltage battery by means of a two-phase voltage

In this mode, switches S1-S2 are closed and S3-S6 are open, so that the ac power of the external grid is filtered by motor inductors L1, L2 and transmitted to the traction power conversion unit 13, where the traction power conversion unit 13 is composed of Q1-Q4 switching tubes, Q5-Q6 are not operated.

Further, the switches S7 and S8 are opened, the switches S1 and 2PS2 are closed, the switches 3PS3 and 3PS4 are opened, the direct current output from the traction power conversion unit 13 is input to the first end of the bidirectional buck-boost conversion unit 14, the bidirectional buck-boost conversion unit 14 performs a boost operation on the direct current output from the traction power conversion unit 13, and the boosted direct current is transmitted from the second end of the bidirectional buck-boost conversion unit 14 to the H-bridge inverter 15, which converts the boosted direct current back to alternating current. The ac power converted by the H-bridge inverter 15 is voltage-regulated by the first isolation transformer 161, and then transmitted to the first rectifier 171 to be converted into dc power again by the first rectifier 171, and the first rectifier 171 transmits the rectified dc power to the high-voltage battery 18 to charge the high-voltage battery.

1.3 charging Low-Voltage batteries by means of three-phase Voltage

In this mode, switches S1-S3 are closed and S4-S6 are open, so that the ac power of the external power grid is filtered by motor inductors L1, L2, L3 and then transmitted to traction power converter unit 13, which consists of Q1-Q6 switching tubes, traction power converter unit 13 operates in a rectifier mode to convert the ac power of the external power grid to dc power.

Further, the switches S7 and S8 are opened, the switches S1 and 2PS2 are opened, the switches 3PS3 and 3PS4 are closed, the direct current output from the traction power conversion unit 13 is input to the second end of the bidirectional buck-boost conversion unit 14, the bidirectional buck-boost conversion unit 14 performs a buck operation on the direct current output from the traction power conversion unit 13, and the buck direct current is transmitted from the first end of the bidirectional buck-boost conversion unit 14 to the H-bridge inverter 15, and the H-bridge inverter 15 converts the buck direct current back to alternating current. The ac power converted by the H-bridge inverter 15 is regulated by the second isolation transformer 162, and then transmitted to the second rectifier 172 to be converted into dc power again by the second rectifier 172, and the second rectifier 172 transmits the rectified dc power to the low-voltage battery 19 to charge the low-voltage battery.

1.4 charging Low-Voltage batteries by means of two-phase Voltage

Further, the switches S7 and S8 are opened, the switches S1 and 2PS2 are closed, the switches 3PS3 and 3PS4 are opened, the direct current output from the traction power conversion unit 13 is input to the first end of the bidirectional buck-boost conversion unit 14, the bidirectional buck-boost conversion unit 14 performs a boost operation on the direct current output from the traction power conversion unit 13, and the boosted direct current is transmitted from the second end of the bidirectional buck-boost conversion unit 14 to the H-bridge inverter 15, which converts the boosted direct current back to alternating current. The ac power converted by the H-bridge inverter 15 is regulated by the second isolation transformer 162, and then transmitted to the second rectifier 172 to be converted into dc power again by the second rectifier 172, and the second rectifier 172 transmits the rectified dc power to the low-voltage battery 19 to charge the low-voltage battery.

1.5 charging Low-Voltage batteries by means of high-Voltage batteries

The operating mode refers to charging the low-voltage battery by means of the high-voltage battery of the vehicle. In this mode, the switches 2PS2, 3PS4, and S7 are open, and S8 is closed, and dc power from the high voltage battery 18 is transmitted to the H-bridge inverter 15 via the switch S8. The H-bridge inverter 15 converts the direct current into alternating current, performs voltage regulation by means of the second isolation transformer 162, and the regulated alternating current is further sent to the second rectifier 172 to be converted back into direct current by means of the second rectifier 172, and the second rectifier 172 transmits the rectified direct current to the low-voltage battery 19 to charge it.

1.6 charging high-Voltage batteries by means of regenerative energy

In this mode of operation, switches S1-S3 are open, S4-S6 are closed, and the vehicle motor functions as a generator. The alternating current generated by the motor under the feedback of the regenerated energy is transmitted to the traction power conversion unit 13, and the traction power conversion unit 13 consists of Q1-Q6 switching tubes and works in a rectification mode to convert the alternating current provided by the motor into direct current.

Further, switches 2PS1 and 3PS3 are open; at the same time, switch S7 is closed and the converted dc power is transmitted to the high voltage battery 18 via switch S7 to charge it.

b. Drive mode

The operation mode refers to driving the vehicle motor by means of the high voltage battery, in which the switch S8 is opened and the switch S7 is closed, and the switches 2PS1 and 3PS3 are opened, and the direct current from the high voltage battery 18 is transmitted to the traction power converting unit 13 via the switch S7, at which time, the traction power converting unit 13 is composed of Q1-Q6 switching tubes, and operates in an inverter mode to convert the direct current of the high voltage battery 18 into alternating current, further, the switches S1-S3 are opened, the switches S4-S6 are closed, and the inductors L1-L3 are configured as winding coils to drive the motor to rotate by means of the alternating current converted by the traction power converting unit 13.

Additionally or alternatively, while the motor is driven in rotation by the high-voltage battery 18, S8 is closed, while switches 2PS2 and 3PS4 are open, the direct current from the high-voltage battery 18 is transmitted via switch S8 to the H-bridge inverter 15, which converts the direct current from the high-voltage battery 18 into alternating current, which is regulated by means of the second isolation transformer 162, the regulated alternating current is further fed to the second rectifier 172 to be reconverted into direct current by means of the second rectifier 172, and the second rectifier 172 transmits the rectified direct current to the low-voltage battery 19 to charge it.

As a second example, assuming that the vehicle motor operates at a voltage platform of 800v and the high voltage battery operates at a voltage platform of 400v, several main operating modes of the integrated electric drive system for a vehicle according to the present invention under this platform can be described as follows.

a. Charging mode

2.1 charging high-Voltage batteries by means of three-phase Voltage

2.2 charging high-Voltage batteries by means of two-phase Voltage

2.3 charging Low-Voltage batteries by means of three-phase Voltage

In this mode, switches S1-S3 are closed and S4-S6 are open, so that the ac power of the external grid is filtered by the motor inductances L1, L2, L3 and is transmitted to the traction power conversion unit 13, the traction power conversion unit 13 operates in a rectification mode to convert the ac power of the external grid into dc power.

2.4 charging Low-Voltage batteries by means of two-phase Voltage

2.5 charging Low-Voltage batteries by means of high-Voltage batteries

2.6 charging the high-voltage battery by means of the regenerative energy of the electric machine

Further, 2PS1 and 2PS2 are opened, 3PS3 and 3PS4 are closed, the switch S7 is opened, S8 is closed, the direct current output from the traction power conversion unit 13 is input to the second end of the bidirectional buck-boost conversion unit 14, the bidirectional buck-boost conversion unit 14 performs a step-down operation on the direct current output from the traction power conversion unit 13, and the stepped-down direct current is transmitted from the first end of the bidirectional buck-boost conversion unit 14 to the high-voltage battery 18 by means of the switch S8 to charge the high-voltage battery 18.

b. Drive mode

The operation mode refers to driving the vehicle motor by means of the high voltage battery, in which the switches 2PS1 and 2PS2 are opened, the switches 3PS3 and 3PS4 are closed, the switch S7 is opened, the switch S8 is closed, the direct current from the high voltage battery 18 is input to the first end of the bidirectional buck-boost converting unit 14, the bidirectional buck-boost converting unit 14 performs a boosting operation on the direct current, the boosted direct current is transmitted from the second end of the bidirectional buck-boost converting unit 14 to the traction power converting unit 13, at this time, the traction power converting unit 13 is composed of Q1-Q6 switching tubes, and operates in an inverter mode to convert the direct current and alternating current of the high voltage battery 18 into alternating current, further, the switches S1-S3 are opened, the switches S4-S6 are closed, and the inductors L1-L3 are configured as winding coils to drive the motor to rotate by means of the alternating current converted by the traction power converting unit 13.

Additionally or alternatively, the low-voltage battery 19 can be charged by means of the high-voltage battery 18 while the electric machine is being driven in rotation, in which case the direct current from the high-voltage battery 18 is transmitted via a switch S8 to the H-bridge inverter 15, which converts the direct current from the high-voltage battery 18 into alternating current, which is regulated by means of the second isolating transformer 162, which regulated alternating current is further fed to a second rectifier 172 for conversion into direct current by means of the second rectifier 172, which second rectifier 172 transmits the rectified direct current to the low-voltage battery 19 for charging thereof.

As a third example, assuming that both the vehicle motor and the high-voltage battery operate at a 800v voltage platform, unlike the first and second examples, in a mode of charging the high-voltage or low-voltage battery by external three-phase alternating current, the switches 2PS1 and 2PS2 are closed, the switches 3PS3 and 3PS4 are open, and the switches S7 and S8 are open, thereby performing a boosting operation on the direct current from the traction power conversion unit 13 by the bidirectional boost-buck conversion unit 14 and transmitting the boosted direct current to the charge conversion unit for charging the high-voltage or low-voltage battery. Further, in the mode of charging the high-voltage battery by means of the regenerative energy of the motor, the switches S8,2PS1, and 2PS2 are closed, and S7, 3PS3, and 3PS4 are opened, so that the direct current from the traction power converting unit 13 is subjected to the boosting operation by means of the bidirectional step-up/step-down converting unit 14, and the boosted direct current is transmitted from the first end of the bidirectional step-up/step-down converting unit 14 to the high-voltage battery 18 by means of the switch S8 to charge it.

It will be appreciated by those skilled in the art that the system according to the invention is not limited to the above-listed modes of operation, but includes all possible modes of operation that can be achieved with the system or circuit arrangement of the invention. For example, the following variants fall within the scope of protection of the present invention:

as a first variation, an external dc power source may be directly connected across the capacitor C1 or C2 to charge the high-voltage battery or the low-voltage battery of the vehicle.

As a second modification, the charge conversion unit (H-bridge inverter 15, isolation transformer, and rectifier) may be omitted, and the high-voltage battery may be directly connected to the bidirectional buck-boost conversion unit 14 (i.e., connected to both ends of C2). For example, the high-voltage battery may be directly connected to the first terminal of the bidirectional buck-boost converting unit 14 by the switch 3PS4, or directly connected to the second terminal of the bidirectional buck-boost converting unit 14 by the switch 2PS2, so that the boosted or stepped-down dc power is directly used for charging the high-voltage battery. In this case, the integrated electric drive system is integrated with the function of a charger, and the control unit 11 can make the charger realize different operation modes by controlling the on and off of the switches S1-S6 and 2PS1,2PS2, 3PS3 and 3PS 4. For example, when the switches S1-S3, 3PS3, and 3PS4 are closed and the switches S4-S6, 2PS1, and 2PS2 are open, the alternating current from the vehicle external power source can be used to charge the high-voltage battery after being subjected to rectification and voltage-reducing operations in sequence.

In addition, the direct current end of the traction power conversion unit 13 can be connected to the high-voltage battery through the switch S7, and the control unit 11 can enable the charger to realize different working modes by controlling the on-off of the switches S1-S6, S7, and 2PS1,2PS2, 3PS3 and 3PS 4. For example, when S4-S6 and S7 are closed and S1-S3, 2PS2 and 3PS4 are open (or S1-S3, 2PS1 and 3PS3 are open), the high voltage battery may be driven by the high voltage battery or charged by regenerating feedback energy from the motor.

The utility model discloses it is emphatically described that control unit 11 has realized the different mode of operation of integrated form electric drive system through the control to the on-off state of each switch S1-S8 and 2PS1,2PS2, 3PS3 and 3PS 4. It will be understood by those skilled in the art that the various modules (e.g., traction power conversion unit 13, bi-directional buck-boost conversion unit 14, H-bridge inverter 15, isolation transformer 161/162, and rectifier 171/172) that make up the integrated electric drive system of the present invention, and in particular the semiconductor switching tubes that make up these modules, may also be controlled. For example, when the traction power conversion unit 13 operates in a rectification mode or an inversion mode, the control unit 11 inputs different control signals through the enable control terminals of the switching tubes Q1-Q6 to control the on/off states of the switching tubes. Since the working mode of each module is not the focus of the protection of the present invention, the description is omitted in some places.

In the present invention, the term "connected" means "electrically connected". Furthermore, the terms "comprises" and "comprising" mean that, in addition to elements directly and explicitly recited in the specification and claims, elements not directly or explicitly recited are excluded from the scope of the present application. Furthermore, terms such as "first", "second", "third", and the like do not denote any order of components or values in time, space, size, or the like, but are used merely to distinguish one component or value from another.

In the present disclosure, one of ordinary skill in the art will appreciate that the disclosed system may be implemented in other ways. The above-described system embodiments are merely illustrative, for example, the division of the modules is only one logical division, and there may be other divisions in actual implementation, for example, the functions of a plurality of modules may be combined or the function of a module may be further split. The modules in the embodiments of the present invention may be integrated into one processing unit, or each module may exist alone physically, or two or more modules may be integrated into one unit.

Although the present invention has been described with reference to the preferred embodiments, the present invention is not limited thereto. Various changes and modifications can be made without departing from the spirit and scope of the present invention, and the scope of the present invention should be determined by the appended claims.

Claims

1. An integrated electric drive system, comprising:

a motor (12) configured to drive the vehicle to run by means of an energy storage unit of the vehicle under the control of the control unit (11), or to charge the energy storage unit of the vehicle by means of a power supply external to the vehicle or regenerative feedback energy of the motor;

an energy storage unit configured to be charged with electric power of a power supply external to the vehicle under the control of the control unit (11), or to drive the vehicle to run by the motor (12), or to supply power to an in-vehicle load;

a first conversion unit (13) configured to convert alternating current generated at the time of regenerative feedback from a power supply or a motor outside the vehicle into direct current or convert direct current from the energy storage unit into alternating current under the control of a control unit (11);

a second conversion unit (14) configured to perform a step-up or step-down operation on the direct current from the first conversion unit (13) or the energy storage unit under the control of a control unit (11);

a third conversion unit configured to convert the direct current from the second conversion unit into direct current for charging the energy storage unit or convert the direct current from the energy storage unit into low-voltage direct current under the control of a control unit (11), wherein the third conversion unit includes:

-an inverter (15) configured to convert direct current from the high voltage battery in the second conversion unit (14) or the energy storage unit into alternating current;

-a first isolation transformer (161) configured to perform a first isolation transformation operation on the alternating current from the inverter (15);

-a first rectifier (171) configured to convert alternating current from the first isolation transformer (161) into direct current for charging a high voltage battery (18) in the energy storage unit;

-a second isolation transformer (162) configured to perform a second isolation transformation operation on the alternating current from the inverter (15); and

-a second rectifier (172) configured to convert alternating current from the second isolation transformer (162) into direct current for charging a low voltage battery (19) in the energy storage unit;

and

a control unit (11) configured to selectively control a vehicle external power source, the electric machine, the first conversion unit, the second conversion unit, the inverter, the first isolation transformer, the second isolation transformer, the first rectifier, the second rectifier and the energy storage unit to achieve different operating modes of the system.

2. The system of claim 1,

the different modes of operation of the system include one or more of driving a motor with the energy storage unit, charging a low voltage battery (19) in the energy storage unit with a high voltage battery (18) in the energy storage unit, charging the energy storage unit with a vehicle external power source, and charging a high voltage battery (18) in the energy storage unit with motor regenerative feedback energy.

3. The system of claim 1,

the electric machine (12) comprises a plurality of coil inductances, each coil inductance (L1, L2, L3) having a first end connected to a vehicle external power source by means of a first switch (S1, S2, S3) and to a neutral point by means of a second switch (S4, S5, S6), a second end connected to an alternating current end of the first conversion unit (13), and the control unit (11) is configured to selectively control the switching on and off of the first and second switches in different operating modes of the system.

4. The system of claim 1,

the energy storage unit comprises a high voltage battery (18) for driving the electric machine (12) and a low voltage battery (19) for powering low voltage devices in the vehicle.

5. The system of claim 1,

the first switching unit (13) comprises six semiconductor switching tubes (Q1-Q6), and the control unit (11) is configured to selectively control the switching of the six semiconductor switching tubes in different operation modes of the system.

6. The system of claim 1,

the second conversion unit (14) comprises two semiconductor switching tubes (Q13, Q14) and a choke inductor (L5), a freewheeling diode is connected in parallel with two ends of the inductor (L5), and the control unit (11) is configured to selectively control the on and off of the two semiconductor switching tubes in different operation modes of the system.

7. The system of claim 3, further comprising:

a third switch (2PS1) connected between a dc terminal of the first conversion unit (13) and a first terminal of the second conversion unit (14);

a fourth switch (2PS2) connected between the second terminal of the second switching unit (14) and the input terminal of the third switching unit;

a fifth switch (3PS3) connected between the dc terminal of the first conversion unit (13) and the second terminal of the second conversion unit (14); and

a sixth switch (3PS4) connected between the first terminal of the second switching unit (14) and the input terminal of the third switching unit,

wherein the control unit (11) is configured to selectively control the on and off of the third, fourth, fifth and sixth switches to cause the second conversion unit (14) to perform a step-up or step-down operation on the direct current from the first conversion unit (13) or the high-voltage battery (18) of the energy storage unit,

wherein the control unit (11) is configured to open the second, third and fourth switches and close the first, fifth and sixth switches to step down the vehicle external power supply for charging the energy storage unit; alternatively, the control unit (11) is configured to open the second, fifth and sixth switches and close the first, third and fourth switches, so that the vehicle external power supply is boosted for charging the energy storage unit.

8. The system of claim 7,

the inverter (15) comprises four semiconductor switching tubes (Q7-Q10), the first isolation transformer (161) and the second isolation transformer (162) are connected in parallel to the output of the inverter (15), and the first rectifier (171) comprises two semiconductor switching tubes (Q11-Q12) and two diodes (D1-D2), the input end of the first rectifier (171) is connected to the first isolation transformer (161), and the output end is connected to the high-voltage battery (18) of the energy storage unit; the second rectifier (172) comprises two semiconductor switching tubes (Q15-Q16) and two diodes (D3-D4), the input end of the second rectifier (172) is connected to the second isolation transformer (162), and the output end of the second rectifier is connected to the low-voltage battery (19) of the energy storage unit.

9. The system of claim 8, further comprising:

a seventh switch (S7) connected between the DC terminal of the first conversion unit (13) and the high voltage battery (18) of the energy storage unit,

wherein the control unit (11) is configured to selectively control the on-off of the first to seventh switches to realize different operation modes of the system,

wherein the control unit (11) is configured to close the second and seventh switches and to open the first, third and fifth switches to drive the motor by means of the high voltage battery (18) of the energy storage unit or to charge the high voltage battery (18) of the energy storage unit by means of regenerative feedback energy of the motor.

10. The system of claim 9, further comprising:

an eighth switch (S8) connected between a high voltage battery (18) of the energy storage unit and an input of the third conversion unit,

wherein the control unit (11) is configured to selectively control the on-off of the first to eighth switches to realize different operation modes of the system,

wherein the control unit (11) is configured to close the eighth switch and to open the fourth and sixth switches to charge the low voltage battery (19) of the energy storage unit by means of the high voltage battery (18) of the energy storage unit.

11. The system of claim 1,

the control unit (11) selectively controls the charging of the high-voltage battery (18) of the energy storage unit or of the low-voltage battery (19) of the energy storage unit as a function of the states of charge of the high-voltage battery (18) of the energy storage unit and of the low-voltage battery (19) of the energy storage unit.

12. The system of claim 1, further comprising:

a first L C filter connected in parallel to the output of the first rectifier (171) for filtering harmonics in the output signal of the first rectifier (171);

a second L C filter connected in parallel to the output of the second rectifier (172) for filtering harmonics in the output signal of the second rectifier (172);

a first filter capacitor (C1) connected in parallel to the DC terminal of the first conversion unit (13) for filtering out harmonics in the DC terminal signal of the first conversion unit (13); and/or

A second filter capacitor (C2) connected in parallel to the input of the third converting unit for filtering out harmonics in the input signal of the third converting unit.

13. The system of claim 10,

the first to eighth switches (S1-S8,2PS1,2PS2, SPS3,3PS4) are controlled switches or semiconductor switches, and the semiconductor switch tubes (Q1-Q16) are field effect transistors or insulated gate bipolar transistors, and a free wheel diode is connected in parallel to each semiconductor switch tube.

14. An electric vehicle, characterized in that it comprises an integrated electric drive system according to one of the preceding claims.