Inverter device, electric drive system comprising same and power assembly

Abstract

The utility model relates to an inverter device, an electric drive system comprising the inverter device, and a power assembly. The inverter device comprises: at least two inverter circuits; the control chip is configured to receive the torque request values of the at least two motors from a vehicle control unit and determine the required voltage which should be distributed to the corresponding inverter circuit based on the received torque request values of the motors; and the driving circuit is configured to drive each switching tube in the corresponding inverter circuit to be switched on and switched off according to the required voltage distributed by the control chip, so that the at least two motors are controlled to output corresponding target torques. According to the inverter device provided by the utility model, the working efficiency of the motor driving system can be improved, the motor control strategy can be optimized, and the utilization efficiency of the voltage of the battery pack can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of vehicles, and more specifically, to an inverter device, an electric drive system including the inverter device, and a powertrain including the electric drive system. Background Art

[0002] In new energy vehicles (such as electric vehicles and hybrid vehicles), the inverter device is the core component for realizing vehicle power conversion. The inverter device is responsible for obtaining the torque command of the motor from the vehicle control unit (VCU) and obtaining electric energy from the power battery pack. After the inverter conversion, it controls the operation of the motor, thereby providing driving torque for the vehicle to ensure the normal driving function of the vehicle.

[0003] In electric vehicles, there is often a need to drive two motors at the same time. The traditional single-bridge dual-motor architecture usually adopts an independent architecture of dual inverters, that is, each motor needs to be equipped with an independent inverter. This dual-inverter architecture means that more space is required in the vehicle to install and arrange the inverter, which not only increases the design complexity and cost of the electric drive system, but also imposes a large restriction on the space utilization of the entire vehicle. Secondly, the dual inverter cannot effectively share the battery pack voltage, resulting in inefficient utilization of the battery pack voltage, which directly affects the working efficiency of the motor and the performance of the entire vehicle. In addition, when the dual inverter has different motor hardware conditions, it is difficult to achieve a balance between the torque output of the left and right motors, which may lead to a decrease in vehicle performance under certain working conditions. Utility Model Content

[0004] In order to solve the above problems existing in the existing dual-motor inverter architecture, the utility model proposes a new inverter device. The inverter device adopts an inverter bridge series architecture, which aims to efficiently convert the DC power of a single battery pack into AC power for driving at least two motors through an intelligent control strategy, thereby achieving precise torque control.

[0005] According to the inverter device of the present invention, by sharing a single battery pack voltage and implementing dynamic adjustment and distribution of the battery pack voltage between two motors, not only the working efficiency of the motor drive system can be improved and the motor control strategy can be optimized, but also the utilization efficiency of the battery pack voltage can be improved, thereby improving the overall performance of the electric vehicle.

[0006] The first aspect of the utility model provides an inverter device, which is connected between a single battery pack and at least two motors, and is used to control the at least two motors to output a target torque by means of the power of the battery pack. According to an optional embodiment, the inverter device includes:

[0007] at least two inverter circuits, wherein a DC end of each inverter circuit is connected in series to a DC output bus of the battery pack, and an AC end is connected to a corresponding one of the at least two motors;

[0008] A control chip, wherein the control chip is configured to receive torque request values ​​of the at least two motors from a vehicle controller and determine a required voltage to be allocated to a corresponding inverter circuit based on the received torque request values ​​of each motor; and

[0009] A drive circuit, wherein the drive circuit is configured to drive the on and off of each switch tube in the corresponding inverter circuit according to the required voltage allocated by the control chip, thereby controlling the at least two motors to output corresponding target torques.

[0010] According to an optional embodiment, the at least two inverter circuits include a first inverter circuit and a second inverter circuit, which are respectively connected to a first motor and a second motor having the same operating voltage.

[0011] According to an optional embodiment, the control chip is configured to evenly distribute the output voltage of the battery pack to the first inverter circuit and the second inverter circuit under normal operating conditions.

[0012] According to an optional embodiment, the control chip is further configured to monitor the output torque of the first motor and the second motor, and adjust the required voltage allocated to the first inverter circuit and the second inverter circuit in real time based on the monitored output torque.

[0013] According to an optional embodiment, the control chip is further configured to short-circuit the first inverter circuit based on an instruction from a vehicle controller, and distribute all the output voltage of the battery pack to the second inverter circuit.

[0014] According to an optional embodiment, the driving circuit is a gate driver.

[0015] According to an optional embodiment, the at least two motors are three-phase motors, and the at least two inverter circuits are three-phase bridge circuits.

[0016] A second aspect of the present utility model provides an electric drive system for a vehicle. According to an optional embodiment, the electric drive system includes:

[0017] at least two electric motors; and

[0018] An inverter device as described above.

[0019] A third aspect of the present utility model provides a powertrain for a vehicle. According to an optional embodiment, the powertrain includes:

[0020] Battery packs; and

[0021] Electric drive system as described above.

[0022] According to an optional embodiment, the battery pack is a power battery pack of a vehicle.

[0023] According to the inverter device of the present invention, by sharing a single battery pack voltage and implementing dynamic adjustment and distribution of the battery pack voltage between two motors, not only the working efficiency of the motor drive system can be improved and the motor control strategy can be optimized, but also the utilization efficiency of the battery pack voltage can be improved, thereby improving the overall performance of the electric vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] By incorporating the accompanying drawings and Figure 1 With reference to the specific implementation modes used to illustrate certain principles of the present invention, other features and advantages of the method of the present invention will become clear or be described in more detail.

[0025] Figure 1 A simplified schematic diagram of an inverter device according to an exemplary embodiment of the present invention is shown.

[0026] Figure 2 Shows Figure 1 Internal circuit diagram of the inverter device in. DETAILED DESCRIPTION

[0027] The inverter device according to the utility model will be described below with reference to the accompanying drawings and by way of example. In the following description, many specific details are set forth so that a person skilled in the art can more fully understand the utility model. However, it is obvious to a person skilled in the art that the implementation of the utility model may not have some of these specific details. On the contrary, it is contemplated that the utility model may be implemented with any combination of the following features and elements, regardless of whether they relate to different embodiments. Therefore, the following aspects, features, embodiments and advantages are for illustrative purposes only and should not be regarded as elements or limitations of the claims unless explicitly stated in the claims.

[0028] Figure 1 FIG. 2 shows a simplified schematic diagram of an inverter device according to an exemplary embodiment of the present utility model. Figure 1 As shown in FIG. 1 , the basic structure of the inverter device T includes two inverter circuits H1 and H2, which are respectively connected in series to the DC output bus of the battery pack BAT at the DC end, and are independently connected to the corresponding motors M1 and M2 at the AC end. Each inverter circuit includes a series of switch tubes, which generate AC power for driving the motor by alternately turning on and off at the AC end.

[0029] The two inverter circuits H1 and H2 are controlled by a single control chip CP1 and a drive circuit D1. The control chip CP1 is the brain of the inverter device T. It receives torque request values ​​from the vehicle control unit (VCU) and calculates the voltage required for each inverter circuit based on these request values. The control chip ensures that the motor can output the required torque through precise algorithms.

[0030] The drive circuit D1 is responsible for accurately controlling the on / off state of the switch tube in the inverter circuit according to the instructions of the control chip, thereby achieving accurate control of the motor current and ensuring that the motor outputs the target torque. The drive circuit D1 can usually use a gate driver, which can provide fast switching response and reduce switching losses, thereby further improving the energy efficiency of the system.

[0031] Figure 2 Shows Figure 1 The internal circuit diagram of the inverter device in FIG. Here, the motors M1 and M2 can be three-phase motors (including three-phase windings U, V, and W), especially permanent magnet synchronous motors M (abbreviated as "PMSM") that can be applied to the BSG system of hybrid vehicles. The two motors M1 and M2 can be driven by a single inverter device T.

[0032] The inverter device T may include a bus capacitor, which is connected between the positive and negative electrodes BAT+ and BAT- of the battery pack BAT. In addition, the inverter device T may also include a control chip CP1, a drive circuit D1 and two inverter circuits H1 and H2. In the inverter circuit H1, the switch tubes T1, T2, and T3 form an upper bridge arm, and the switch tubes T4, T5, and T6 form a lower bridge arm. In the inverter circuit H2, the switch tubes T7, T8, and T9 form an upper bridge arm, and the switch tubes T10, T11, and T12 form a lower bridge arm. Here, each bridge arm may adopt a field effect transistor (MOSFET), an insulated gate bipolar transistor (IGBT) or a bipolar junction transistor (BJT).

[0033] like Figure 2 As shown in the figure, two inverter circuits H1 and H2 are connected in series on the DC output bus of the battery pack BAT, and are used to control motors M1 and M2 respectively. The control chip CP1 and the drive circuit D1 can coordinately distribute the power supply voltage of the battery pack BAT between the inverter circuits H1 and H2.

[0034] Specifically, the gate control terminals of the switches in the inverter circuits H1 and H2 can be connected to the gate driver D1, which controls the conduction of the switches based on the PWM duty cycle signal provided by the control chip CP1, thereby controlling the output torque of the motor.

[0035] According to an optional example, assuming that the two motors M1 and M2 have the same operating voltage (for example, 400V), under normal operating conditions, the control chip CP1 can distribute the output voltage of the battery pack BAT (for example, 800V) evenly to the two inverter circuits H1 and H2 to ensure that the two motors can receive power evenly.

[0036] Optionally, during the operation of the motor, the control chip CP1 can also monitor the output torque of each motor and adjust the required voltage of the two inverter circuits in real time according to the actual operation conditions to optimize the control performance of the motor. Taking the three-phase motors M1 and M2 as an example, the corresponding inverter circuits H1 and H2 can adopt a three-phase bridge circuit. This configuration can provide stable three-phase AC power to the motor, thereby ensuring smooth operation of the motor.

[0037] In certain specific circumstances, for example, when the vehicle controller instructs to shut down one of the motors M1, the control chip CP1 can short-circuit the inverter circuit H1 corresponding to the motor M1 based on the instruction, and allocate all the output voltage (for example, 800V) of the battery pack BAT to the other inverter circuit H2 to meet the operating requirements under this condition.

[0038] It is worth noting that, although the specific architecture of the inverter device according to the present invention is clearly described, the above reference Figure 1 The scheme is described by taking a single battery pack BAT to drive two motors M1 and M2 as an example, but those skilled in the art can understand that the inverter device of the utility model is not limited to Figure 1 For example, there may be a scenario in which a single battery pack is required to drive three, four or even more motors in a vehicle, and a corresponding inverter circuit may be added to the inverter device of the utility model to meet the needs of more motor scenarios. These variations fall within the protection scope of the utility model.

[0039] An embodiment of the present invention also provides an electric drive system for a vehicle, the electric drive system comprising at least two motors and Figure 1 , Figure 2 An inverter device is described.

[0040] Another embodiment of the present invention also provides a powertrain for a vehicle, the powertrain comprising a battery pack BAT and the electric drive system as described above, wherein the battery pack BAT can be a power battery pack inside the vehicle.

[0041] According to the inverter device of the present invention, by sharing a single battery pack voltage and implementing dynamic adjustment and distribution of the battery pack voltage between two motors, not only the working efficiency of the motor drive system can be improved and the motor control strategy can be optimized, but also the utilization efficiency of the battery pack voltage can be improved, thereby improving the overall performance of the electric vehicle.

[0042] Although some aspects of the present invention have been presented and discussed, those skilled in the art will appreciate that the above aspects may be modified without departing from the principles and spirit of the present invention, and therefore the scope of the present invention shall be defined by the claims and their equivalents. Furthermore, terms such as "first" and "second" do not indicate the order of units or values ​​in terms of time, space, size, etc., but are merely used to distinguish between units or values.

Claims

1. An inverter device, connected between a single battery pack and at least two motors (M1, M2), for controlling the at least two motors (M1, M2) to output a target torque by means of power from the battery pack, characterized in that: The inverter device comprises: at least two inverter circuits (H1, H2), a DC end of each inverter circuit being connected in series to a DC output bus of the battery pack, and an AC end being connected to a corresponding one of the at least two motors; A control chip (CP1), the control chip being configured to receive torque request values ​​of the at least two motors (M1, M2) from a vehicle controller and determine a required voltage to be allocated to a corresponding inverter circuit based on the received torque request values ​​of each motor; and A drive circuit (D1), wherein the drive circuit is configured to drive the on and off of each switch tube in the corresponding inverter circuit according to the required voltage allocated by the control chip (CP1), thereby controlling the at least two motors (M1, M2) to output corresponding target torques.

2. The inverter device according to claim 1, characterized in that: The at least two inverter circuits (H1, H2) include a first inverter circuit (H1) and a second inverter circuit (H2), which are respectively connected to a first motor (M1) and a second motor (M2) having the same operating voltage.

3. The inverter device according to claim 2, characterized in that: The control chip (CP1) is configured to evenly distribute the output voltage of the battery pack to the first inverter circuit (H1) and the second inverter circuit (H2) under normal operating conditions.

4. The inverter device according to claim 2 or 3, characterized in that: The control chip (CP1) is further configured to monitor the output torque of the first motor (M1) and the second motor (M2), and adjust the required voltage allocated to the first inverter circuit (H1) and the second inverter circuit (H2) in real time based on the monitored output torque.

5. The inverter device according to claim 2 or 3, characterized in that: The control chip (CP1) is further configured to short-circuit the first inverter circuit (H1) based on an instruction from a vehicle controller, and distribute all the output voltage of the battery pack to the second inverter circuit (H2).

6. The inverter device according to any one of claims 1 to 3, characterized in that: The driving circuit (D1) is a gate driver.

7. The inverter device according to any one of claims 1 to 3, characterized in that: The at least two motors (M1, M2) are three-phase motors, and the at least two inverter circuits (H1, H2) are three-phase bridge circuits.

8. An electric drive system for a vehicle, characterized in that: The electric drive system includes: at least two motors (M1, M2); and The inverter device according to any one of claims 1 to 7.

9. A powertrain for a vehicle, characterized in that: The powertrain includes: Battery packs; and The electric drive system according to claim 8.

10. The powertrain according to claim 9, characterized in that: The battery pack is a power battery pack of a vehicle.

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