Self-boosting doubly-salient brushless direct-current power generation system

Abstract

The invention discloses a self-boosting doubly-salient brushless direct-current power generation system. An armature winding and two excitation windings which are in magnetic coupling mutually are arranged in a doubly-salient motor of the self-boosting doubly-salient brushless direct-current power generation system. The armature winding, a bridge rectifier circuit, the first excitation winding, a diode, a first power switch tube and a capacitor are respectively and sequentially connected, the second excitation winding is sequentially connected with an asymmetrical half-bridge circuit and a direct-current excitation source, an engine detecting and controlling unit is used for detecting the output voltage, the output current and the excitation current of the power generation system and controlling the duty ratio of the asymmetrical half-bridge circuit and the first power switch tube. The invention further discloses a control method of the self-boosting doubly-salient brushless direct-current power generation system. According to the method, under the conditions of the constant rotation speed and the variable rotation speed, the efficiency and the output power of the power generation system are improved through coordination control of the duty ratio between the excitation current and the first power switch tube.

Description

technical field [0001] The invention relates to a double salient pole brushless direct current power generation system, in particular to a self-boosting double salient pole brushless direct current power generation system, which belongs to the technical field of double salient pole brushless direct current power generation. Background technique [0002] A series hybrid electric vehicle is a purely electric drive hybrid electric vehicle that uses a vehicle-mounted DC generator set and a power storage battery to form a dual power source. There is no mechanical power coupling between the engine and the wheels, and there is no mechanical connection between the change of the engine speed and the wheel speed, so that the engine runs at a constant speed at the best efficiency point, which improves fuel economy and reduces emissions. In parallel hybrid electric vehicles, there is a mechanical coupling between the engine and the wheels, so the on-board DC generator installed coaxiall...

AI Technical Summary

Problems solved by technology

However, the electric excitation double salient pole brushless DC power generation system requires an external excitation source to provide excitation power for the excitation winding, which reduces the efficiency of the power generation system. In the hybrid excitation double salient pole brushless DC power generation system, the stator of the hybrid excitation double salient pole motor needs a permanent Magnetic steel increases system cost, and reduces system reliability due to the risk of irreversible demagnetization of permanent magnets in vibration and high temperature environments

[0005] On the other hand, the output voltage value of the electric excitation double salient pole brushless DC power generation system is clamped on the DC bus with the same voltage value as the power battery pack connected in parallel. By adjusting the excitation current in the excitation winding installed on the stator, the The power generation system outputs a given current to meet the power requirements of the power storage battery pack and the rear-stage drive system. However, the output characteristics of the electric excitation double salient pole brushless DC power generation system are that as the excitation current and speed change, the output power of the power generation system The voltage value corresponding to the maximum power point cannot always be kept equal to the voltage value of the external DC bus. Therefore, when the speed or excitation current changes, the electric excitation double-salient pole brushless DC power generation system cannot maintain high-efficiency work all the time, and it is even difficult to achieve idle power generation.

[0006] If a booster circuit is added to the rear stage of the electric excitation double salient pole brushless DC power generation system, the output voltage of the power generation system is increased under different excitation current or speed conditions, so that the voltage corresponding to the maximum power point is consistent with the bus voltage, and the maximum Efficient use of electrically excited doubly salient motors improves system efficiency. However, the front stage of the boost circuit requires a large inductance, and the large inductance has a large volume and weight, making it difficult to integrate the system and causing greater electromagnetic interference.

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