Coupling system for electric eddy current braking and regenerative braking of electric vehicle and control method thereof

Abstract

The invention discloses a coupling system for electric eddy current braking and regenerative braking of an electric vehicle. The coupling system comprises an electric eddy current brake assembly, a motor assembly, an energy storage device assembly, an insulated gate transistor T1, an insulated gate transistor T2, an insulated gate transistor T3, an electromagnetic relay K1, an electromagnetic relay K2, an inductor L2 and a filter capacitor C1 assembly. The combined control of the insulated gate transistors and the electromagnetic relays achieves a motor driving mode, a mode of electric eddy current braking independently driven by an energy storage device, a regenerative braking mode, a regenerative braking coupling electric eddy current braking mode and a mode of electric eddy current braking independently driven by a motor. The coupling system for electric eddy current braking and regenerative braking of the electric vehicle has the beneficial effects of providing various selectable electric braking modes, improving the controllable range of electric braking torque, reducing the proportion of a friction braking system, improving the braking performance of the vehicle, enabling rectified currents to be controllable by controlling a trigger delay angle, improving the energy utilization rate, and fully recovering braking energy to a higher degree.

Description

technical field [0001] The invention relates to a braking system of an electric vehicle and a control method thereof, in particular to a coupling system of eddy current braking and regenerative braking of an electric vehicle and a control method thereof, belonging to the field of automobile braking systems. Background technique [0002] Eddy current braking is also called eddy current retarding or electromagnetic braking, and generally consists of a stator, a rotor and a fixed bracket. When the retarder is working, the stator coil is energized to generate a magnetic field, and the rotor rotates with the transmission shaft. The rotor cuts the magnetic field lines generated by the stator, thereby generating a vortex-shaped induced current inside the rotor disk. In this way, the stator will apply an electromagnetic force to the rotor that hinders the rotation of the rotor, thereby generating a braking torque. At the same time, the eddy current circulates inside the rotor disk...

AI Technical Summary

Problems solved by technology

[0005] However, regenerative braking technology is restricted by factors such as motor characteristics and battery characteristics, and the braking torque provided is small, which cannot meet the braking needs of the car. As an auxiliary braking, it needs to be coordinated with friction braking for control

For example, when the vehicle speed decreases, the electromotive force generated by the motor is very low, and it is difficult to use DC / DC boost to charge the battery. If the motor performs pure motor energy consumption braking, the winding resistance is very small, even if the electromotive force of the generator is already small. , but the pure motor energy consumption braking current is still very large, too large will cause the motor to heat up, and it is difficult to perform regenerative braking; when braking on a long downhill slope, if the battery charge state is too high, regenerative braking cannot be used

[0006] Chinese patent CN201610027625.6 discloses a working method of an integrated braking device of electromagnetic braking and friction braking. Working mode, this working method indirectly controls the working condition of the friction brake by controlling the electromagnetic brake, which solves the problem that the electromagnetic brake and the friction brake work independently and the coordination control is complex in the prior art

However, due to the small electromagnetic braking torque, it cannot meet the actual braking requirements. In the actual braking process, friction braking is still dominant, which is not conducive to energy recovery and prolonging the service life of braking components, and the braking efficiency is low.

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