Motor drive system with automatic switching capacity and control method thereof

Abstract

The invention discloses a motor drive system with automatic switching capacity and a control method thereof. The motor drive system is used for an electric vehicle. The motor drive system comprises a first motor, a second motor, a vehicle controller and a charge and discharge system. The vehicle controller controls the first motor and the second motor to drive or brake the electric vehicle. The charge and discharge system supplies power to the electric vehicle and receives electric energy released by the first motor and the second motor when the vehicle is braked. The first motor and the second motor are each of a double-output-shaft structure. One end of the first motor is connected with a load device, and the other end of the first motor is connected with an input shaft of the second motor through a clutch and a transmission shaft. The output shafts of the second motor are connected with a main speed reducer of the vehicle through a reduction gearbox or directly connected with the main speed reducer. The motor drive system can generate large torque when the vehicle works at a low speed and has proper power when the vehicle is operated at medium and high speeds.

Description

technical field [0001] The invention relates to a motor drive system and its control method, in particular to an integrated motor drive system with automatic switching capability and its control method. Background technique [0002] At present, for electric vehicles powered by electric motors, including electric vehicles, fuel cell electric vehicles and series hybrid electric vehicles, the power performance of the whole vehicle must meet certain requirements, including performance indicators such as climbing ability, maximum speed, acceleration ability, etc. . Therefore, the motor drive system must have mechanical characteristics that are compatible with the power of the vehicle, and should have high efficiency and low cost. In addition, the motor drive system should also have the ability to regenerate braking energy. When braking, it also needs to be fed back to the vehicle energy storage system through the motor drive system. In order to achieve these requirements, an id...

AI Technical Summary

Problems solved by technology

However, the maximum torque of the motor drive system corresponding to curve b is low, and the climbing ability of the vehicle using this motor drive system cannot meet the requirements. The motor drive system corresponding to curve c, although the maximum torque and power at medium and high speeds can meet the requirements , but the power of the drive system is much larger than the actual power demand, and the power reserve is too large, which will inevitably cause problems such as high cost, low load rate, high quality and low efficiency of the motor drive system

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