Motor driving system for vehicle bidirectional quasi-Z-source inverter

Abstract

The invention relates to a motor driving system for a vehicle bidirectional quasi-Z-source inverter. The motor driving system comprises a speed regulation control module, a sensor unit, and a power supply module, a bidirectional quasi-Z-source preceding-stage passive network, a three-phase bridge type inverter and a motor which are connected in sequence, wherein the bidirectional quasi-Z-source preceding-stage passive network and the three-phase bridge type inverter form the bidirectional quasi-Z-source inverter; the speed regulation control module is connected with the sensor unit and the bidirectional quasi-Z-source inverter separately; and the bidirectional quasi-Z-source preceding-stage passive network comprises inductors L1 and L2, capacitors C1 and C2, an IGBT switch tube S7 and a diode D7. Compared with the prior art, the bidirectional quasi-Z-source inverter system established by the invention, taken as the single-stage inverter system, can replace the two-stage conversion DC / DC and DC / AC conversion in the conventional electric driving field to avoid voltage fluctuation of the battery pack and maintain the stable and adjustable direct bus voltage; and in addition, the problem of dead time existing in the conventional inverter is prevented, so that the output voltage distortion can be lowered, and the torque pulsation and electromagnetic noises can be reduced.

Description

technical field [0001] The invention relates to the field of motor drive systems for vehicles, in particular to a motor drive system for bidirectional quasi-Z source inverters for vehicles. Background technique [0002] In the traditional motor drive system, the inverter is a voltage type inverter, which has the following disadvantages: [0003] 1. The bus voltage of the voltage-type inverter is the output voltage of the battery, which is limited by the battery voltage. When the car is climbing and accelerating, the voltage will drop when the battery is insufficient, resulting in insufficient output power of the motor. In order to improve Due to the soft characteristics of battery output, a non-isolated BOOST circuit is usually added to the output end of the battery in fuel cell vehicles and electric commercial vehicles. After the BOOST circuit increases the voltage, it is supplied to the three-phase bridge inverter to drive the motor. The level DC / DC inverter is a two-leve...

AI Technical Summary

Problems solved by technology

[0003] 1. The bus voltage of the voltage-type inverter is the output voltage of the battery, which is limited by the battery voltage. When the car is climbing and accelerating, the voltage will drop when the battery is insufficient, resulting in insufficient output power of the motor. In order to improve Due to the soft characteristics of battery output, in fuel cell vehicles and electric commercial vehicles, a non-isolated BOOST circuit is usually added to the output end of the battery. After the BOOST circuit increases the voltage, it supplies the three-phase bridge inverter to drive the motor. The first-stage DC / DC inverter is a two-stage circuit, and the transmission efficiency of the system as a whole is low after two-stage conversion

[0004] 2. The upper and lower bridge arms of the traditional voltage-type inverter cannot be turned on at the same time, and the dead time needs to be increased. However, the existence of the dead time will distort the output voltage and current, increase the torque ripple of the system, and increase the electromagnetic force of the system. Noise affects the comfort and reliability of the electric drive system

The circuit structure of this patented inverter is applied in the field of photovoltaic parallel grid. When the light load or the Z source inductance is small, it will appear in an abnormal working state and cannot overcome the influence caused by the intermittent current, and the control method adopts Open-loop control, applied in the field of automotive electric drive technology, cannot achieve the purpose of high-speed speed control

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