CN103640495B - Electric vehicle wheel motor drive control system - Google Patents

Abstract

The invention relates to a drive control system for a wheel motor of an electric vehicle, which belongs to the technical field of electric vehicle drive. The system consists of an inverter and two permanent magnet synchronous wheel motors. The inverter converts the DC power of the high-voltage DC power supply on the electric vehicle into AC power, and the permanent magnet synchronous wheel motor converts the AC power into the mechanical energy required by the vehicle; the inverter and the permanent magnet synchronous motor have high-voltage electrical connections and signals Connection; the inverter includes a signal acquisition and processing unit, a DSP control unit, a drive and logic interlock unit and a main circuit. The invention uses one inverter to control two permanent magnet synchronous wheel motors, and realizes the interlocking of the working states of the two permanent magnet synchronous wheel motors, thereby ensuring the safety of the two permanent magnet synchronous wheel motors and the entire electric vehicle Running, very innovative.

Description

Electric vehicle wheel motor drive control system

technical field

The invention relates to a drive control system for a wheel motor of an electric vehicle, which belongs to the technical field of electric vehicle drive.

Background technique

Because of the advantages of energy saving and environmental protection, electric vehicles have become the research focus of current automotive technology and sustainable development of the automotive industry. Wheelside motor drive is a relatively advanced driving method for electric vehicles. It abandons traditional mechanical transmission components such as reducers, clutches, and transmission bridges, and installs the motor on the wheels directly or indirectly through a reducer. It has unique technical advantages in terms of structure, handling performance, energy utilization, etc., mainly manifested in: the wheel side motor directly drives the wheel, which simplifies the transmission mechanism and improves the transmission efficiency; the driving force of the wheel side motor can be directly controlled, and the operation is convenient and flexible , the electronic differential speed can be realized by reasonably controlling the driving force of the wheels, thereby improving the handling stability of the vehicle; in addition, the wheel-side motor drive system belongs to the multi-motor drive system, which can make the vehicle control the power system, brake energy feedback, etc. be further optimized.

The layout of the wheel-side motor drive system is relatively flexible. It can be used as a wheel-side motor and assembled on the two front wheels, or the two rear wheels, or the four wheels of the electric vehicle. Correspondingly, the electric vehicle becomes a front-wheel drive, rear-wheel drive or four wheel drive. In a general wheel-side motor drive system, each wheel-side motor is equipped with an inverter, and each inverter controls the work of a wheel-side motor according to the vehicle power demand and the driver's driving intention. The coordination between the inverters is usually realized by the vehicle controller sending relevant instructions to the inverters through the CAN bus according to the working status of the vehicle and the wheel motors. For example, for a vehicle driven by dual wheel motors, when the wheel motor on one side of the vehicle fails, the vehicle controller first judges the fault of the wheel motor through the information received by the CAN bus, and transmits instructions through the CAN bus Give the wheel side motor inverter, let it control the wheel side motor to stop its work, and at the same time, send instructions to the other side of the wheel side motor inverter to stop the other side of the motor through the CAN bus, thereby ensuring that the entire vehicle Safety. In this process, due to the delay of CAN bus information and the corresponding time of the inverter, the two wheel motors will not be able to work synchronously and coordinately, which will have a significant impact on the safe and reliable operation of the vehicle.

The present invention adopts an inverter to control the coordinated work of two wheel motors. When a wheel motor fails, the inverter can quickly make a judgment and take corresponding actions for the two wheel motors without being affected. External and communication bus delay or asynchronous factors. Therefore, the present invention has great significance for improving the reliability and safety of the electric vehicle adopting the wheel motor drive system.

Contents of the invention

The purpose of the present invention is to provide a drive control system for wheel motors of electric vehicles, which can be applied to electric vehicles driven by two wheels, and the system can perform synchronous and coordinated control on two wheel motors.

In order to achieve the above object, the electric vehicle wheel motor drive control system involved in the present invention is composed of an inverter and two permanent magnet synchronous motors. The inverter has high voltage electrical connections and signal connections to the permanent magnet synchronous motor.

The inverter converts the high-voltage DC power supply on the electric vehicle, such as a fuel cell, a generator, a battery pack or a super capacitor pack, to convert the DC power output by the permanent magnet synchronous motor into the AC power required by the permanent magnet synchronous motor. The inverter can receive control commands from the electric vehicle controller through the CAN bus. The inverter includes four components: signal acquisition and processing unit, DSP control unit, drive and logic interlock unit and main circuit.

Signal acquisition and processing unit: used to collect and process signals such as the vehicle control signal, the output phase current of the main circuit, the speed and temperature of the permanent magnet synchronous wheel motor, and transmit the processed information to the DSP control unit and the drive and logic interlock unit. Among them, the vehicle control signal comes from the vehicle controller, which mainly reflects the running state of the vehicle, such as the current vehicle speed, and the driver's operation intention, such as the steering wheel steering angle, and instructions, such as the torque command obtained by the vehicle controller according to the driver's pedal, etc. The output phase current of the main circuit comes from the current flowing through the high-voltage electrical connection between the inverter and the permanent magnet synchronous wheel motor; the speed and temperature signal of the permanent magnet synchronous wheel motor comes from the resolver inside the permanent magnet synchronous motor and the temperature sensor.

DSP control unit: with a chip of TMS320F28335 as the core, according to the information provided by the signal acquisition and processing unit, the drive signal of six main circuit IGBTs is obtained by vector control method and PI adjustment.

Drive and logic interlocking unit: It has two functions, one is to perform power amplification and shaping processing on the six driving signals output by the DSP control unit; the other is to perform logic interlocking according to the output signals of the signal acquisition and processing unit. The function of logical interlock is to make two permanent magnet synchronous motors work in coordination, especially when one permanent magnet synchronous wheel motor fails and stops working, the other permanent magnet synchronous wheel motor will also stop working. The specific logic interlock control strategy is as follows:

When the difference between the rotational speeds of the two permanent magnet synchronous wheel motors is greater than the set threshold, the 12-way IGBT drive signals are blocked. The set threshold is determined by the current vehicle speed and the steering angle of the steering wheel;

When any phase current of the two permanent magnet synchronous wheel motors exceeds 120% of the maximum working phase current of the wheel motors, the 12-way IGBT drive signals are blocked at the same time;

When the operating temperature of any permanent magnet synchronous wheel motor reaches or exceeds 80% of the maximum allowable operating temperature of the permanent magnet synchronous wheel motor but is lower than the maximum allowable operating temperature of the permanent magnet synchronous wheel motor, the DSP controls the permanent magnet synchronous wheel The output torque of the motor is 50% of the required torque of the vehicle;

When the working temperature of any permanent magnet synchronous wheel motor reaches or exceeds the maximum allowable working temperature of the permanent magnet synchronous wheel motor, the 12-way IGBT drive signals are blocked.

Main circuit: It is composed of 12 IGBTs and filter capacitors. According to the driving signal, the DC power of the high-voltage power supply of the vehicle is converted into the AC power required by the two permanent magnet synchronous wheel motors.

The present invention is different from the drive system in which each wheel motor has an independent inverter, and uses one inverter to control two permanent magnet synchronous wheel motors, realizing the real-time interlocking of the working states of the two permanent magnet synchronous wheel motors , to ensure the safe operation of the two permanent magnet synchronous wheel motors and the entire electric vehicle, which is very innovative.

Description of drawings

Figure 1 Structural diagram of electric vehicle wheel motor drive control system

detailed description

Referring to the accompanying drawings, the specific implementation of the present invention will be described in detail below.

As shown in Figure 1, the structure diagram of the electric vehicle wheel motor drive control system is given. It can be seen from the figure that the whole system includes an inverter and two permanent magnet synchronous wheel motors. The inverter has high voltage electrical connections and signal connections to the permanent magnet synchronous motor.

The inverter includes a signal acquisition and processing unit, a DSP control unit, a drive and logic interlock unit and a main circuit. Among them, the signal acquisition and processing unit is used to collect and process signals such as the vehicle control signal, the output phase current of the main circuit, the speed and temperature of the permanent magnet synchronous wheel motor, and transmit the processed information to the DSP control unit and the drive and logic Interlocking unit; the DSP control unit is composed of a TMS320F28335 chip as the core. According to the information, the vector control method is used to obtain the driving signal of the IGBT of the main circuit. The driving signal is power amplified and shaped in the driving and logic interlocking unit. The output signal of the signal acquisition and processing unit is logically interlocked and sent to the main circuit to drive the IGBT to work; the main circuit is composed of 12 IGBTs and filter capacitors. According to the driving signal, the DC power of the high-voltage power supply of the vehicle is converted into two permanent magnets. The AC power required to synchronize the wheel motors.

The logic interlock control strategy of the drive and logic interlock unit is as follows: When the difference in the rotational speed of the two permanent magnet synchronous wheel motors is greater than the set threshold, the 12-way IGBT drive signal is blocked; the set threshold is determined by the current vehicle speed and steering wheel steering. The angle is determined; when any phase current of two permanent magnet synchronous wheel motors exceeds 120% of the maximum working phase current of the wheel motors, the 12-way IGBT drive signals are blocked at the same time; when the operating temperature of any permanent magnet synchronous wheel motor When it reaches or exceeds 80% of the maximum allowable operating temperature of the permanent magnet synchronous wheel motor but is lower than the maximum allowable operating temperature of the permanent magnet synchronous wheel motor, the DSP controls the output torque of the permanent magnet synchronous wheel motor to be the required torque of the whole vehicle 50%; when the operating temperature of any permanent magnet synchronous wheel motor reaches or exceeds the maximum allowable operating temperature of the permanent magnet synchronous wheel motor, the 12-way IGBT drive signal is blocked.

Two permanent magnet synchronous wheel motors convert AC power into the mechanical energy required by the vehicle. The rotary transformer and temperature sensor located inside the two permanent magnet synchronous wheel motors generate speed and temperature signals and transmit them to the inverter through the signal connection.

Claims (2)

1. an Electric vehicle wheel motor drive control system, it is characterized in that, it is made up of an inverter and two permanent-magnet synchronous wheel motors, inverter is connected by three-phase alternating current cable and rotating speed temperature signal line with every permanent-magnet synchronous wheel motor, inverter passes through rotating speed temperature and the input phase current of permanent-magnet synchronous wheel motor, use vector control mode that permanent-magnet synchronous wheel motor is controlled, the logical interlock control strategy that inverter employing is following:

When the difference of two permanent-magnet synchronous wheel motor rotating speeds is more than when setting threshold value, blocking 12 road IGBT and drive signal, set threshold value is determined by current vehicle speed wheel steering angle；

When any phase current of two permanent-magnet synchronous wheel motors exceedes the 120% of wheel motor maximum functional phase current, block 12 road IGBT simultaneously and drive signal；

When the operating temperature of any one permanent-magnet synchronous wheel motor meets or exceeds the 80% of the maximum allowable operating temperature of permanent-magnet synchronous wheel motor but is less than the maximum allowable operating temperature of permanent-magnet synchronous wheel motor simultaneously, it is the 50% of car load demand torque that DSP controls the output torque of permanent-magnet synchronous wheel motor；

When the operating temperature of any one permanent-magnet synchronous wheel motor meets or exceeds the maximum allowable operating temperature of permanent-magnet synchronous wheel motor, block 12 road IGBT and drive signal.

Electric vehicle wheel motor drive control system the most according to claim 1, it is characterised in that inverter includes signal acquisition process unit, DSP control unit, driving and logical interlock unit and four parts of main circuit；

Signal acquisition process unit is for whole vehicle control signal, main circuit output current phase, the collection of permanent-magnet synchronous wheel motor rotating speed temperature signal and process, and the information after processing is sent to DSP control unit and drives and logical interlock unit；

DSP control unit is core by a piece of TMS320F28335 chip, the information provided according to signal acquisition process unit, uses vector control method to obtain the driving signal of 12 road main circuit IGBT；

Six tunnels of DSP control unit output drive signal to be amplified in driving with logical interlock unit and process, and deliver to main circuit driving IGBT work；Drive signal to obtain power amplification and Shape correction at driving and logical interlock unit, carry out logical interlock according to the output signal of signal acquisition process unit simultaneously；

Main circuit is made up of 12 IGBT and filter capacitor, according to driving signal the AC energy that the direct current energy inversion of car load high voltage power supply is that two permanent-magnet synchronous wheel motors need.