Impedance type five bridge-arm converter dual-motor drive system and control method thereof

Abstract

The invention relates to a motor drive system, in particular to an impedance type five bridge-arm converter dual-motor drive system and a control method thereof. The system consists of a five bridge-arm converter, an impedance link, a power supply side direct current bus power switching device, a power supply and a permanent magnet alternating current motor; and by controlling the five bridge-arm converter to drive two motors by adopting a simple and easily implemented decoupling algorithm, and by controlling the voltage of a direct current bus of the converter through the cooperation of the power supply side direct current bus power switching device, the impedance link and a power switching device of the five bridge-arm converter, the system can realize a speed expansion operation at a speed higher than a rated speed of the motors, and can also realize an energy feedback process from the motors to a power supply. The system has the advantages that: no short-circuit risk of 'direct connection' between two power switching devices of the same bridge arm of the converter exists; the cost of the converter is saved by using one converter independently to drive two motors; and the voltage of a power supply side direct current bus can be controllably raised, which contributes to solving the problem of 'weak magnetic speed expansion' of the permanent magnet alternating current motor.

Description

technical field [0001] The invention relates to a motor drive system, in particular to a dual-motor drive system for an impedance-type five-bridge-arm converter and a control method thereof. Background technique [0002] Four-wheel independent drive is the future development direction of electric vehicles. By installing a motor in each of the four wheels to form a power dispersion structure, it has the following advantages: traditional mechanical transmission components such as differentials and gearboxes can be eliminated, saving installation space, Improve the transmission efficiency; the high dynamic torque response of the motor can improve the dynamic performance of the vehicle; the controllability of the vehicle is better, zero-radius steering is possible, and the driving ability on bad roads is improved; when a part of the motor system fails, the vehicle will still With operational capability and higher reliability. [0003] At present, permanent magnet brushless moto...

AI Technical Summary

Problems solved by technology

However, there are some deficiencies in the above-mentioned electric vehicle motor system. First, there is a danger of "straight-through" in the voltage-type converter. Severe damage to the converter; second, the four converters require as many as 24 power switching devices, which makes the system cost higher; third, it is difficult to achieve weak magnetic speed expansion for permanent magnet AC motors

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