Combined brushless direct-current starter generator system and control method thereof

Abstract

The invention discloses a combined brushless direct-current starter generator system and belongs to the field of starter power generation technologies. A brushless direct-current starter generator comprises an electrically-excited doubly-salient motor and a permanent magnet motor, wherein the motors are coaxially connected. An armature winding of the electrically-excited doubly-salient motor is connected with a bridge rectifier circuit to serve as a generation output end of the starter generator system. An armature winding of the permanent magnet motor is connected with a bidirectional bridge power conversion circuit and an asymmetric half-bridge circuit. An exciting winding is connected with a midpoint of the asymmetric half-bridge circuit. During starting, the permanent magnet motor drives an engine to start; after starting, the permanent magnet motor serves as the electrically-excited doubly-salient motor exciter providing the exiting winding with exciting current. The invention further discloses a control method of the combined brushless direct-current starter generator system. Starting torque is stable; power generation control is simple; the problem that starting source voltage and generation output voltage are unbalanced is solved; starting and generating functional decoupling control is achieved; starting and power generation switching is simple and reliable to control.

Description

Technical field [0001] The invention relates to a starter-generator system, in particular to a composite brushless DC starter-generator system and a control method thereof, and belongs to the technical field of starter-generator technology. Background technique [0002] The electric excitation doubly salient motor has a simple structure and no windings on the rotor. It is suitable for high-speed operation and improves the power density of the motor. When running for power generation, it does not require a position sensor and the control is flexible and convenient. The electric excitation doubly salient pole motor requires an independent DC excitation source whether it is electric or generating operation. Setting up an exciter can solve its reliable excitation problem. [0003] The integration of starter and power generation can reduce the system volume and make the structure compact, especially in the field of independent power systems in automobiles and aircraft. When the ...

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Problems solved by technology

[0006] The technical problem to be solved by the present invention is to overcome the imbalance between the starting power supply voltage and the output voltage of the generator in the prior art, and provide a composite brushless motor with simple structure, high reliability, low cost and flexible control. DC starter generator system and its control method

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