Method for estimating initial position of rotor of three-stage brushless alternative-current synchronous motor

Abstract

The invention claims a method for estimating an initial position of a rotor of a three-stage brushless alternative-current synchronous motor. The method comprises the steps of acquiring a rotor initial position estimated value by using a pulsating high-frequency voltage injection method, acquiring the rotor section information by using counter potential polarity judging method; and modifying the section of the rotor position estimated value obtained by the pulsating high-frequency voltage injection method according to the rotor section information obtained by the counter potential polarity judging method, so as to obtain the final rotor initial position estimated value. The position estimating method can solve the problems in all researches and obtain the accurate rotor initial position estimated value; the invention has simple structure, easy implementation and high estimation precision; the method provided by the invention does not need to change a topological structure of a start-up system / generating system and increase the extra hardware cost.

Description

technical field [0001] The invention relates to a three-stage brushless AC synchronous motor, in particular to a method for estimating the initial position of the rotor of the motor. Background technique [0002] The high speed, integration, high reliability and high power density of aircraft starting / generating system are the development trend of modern aircraft power system. The starting / generating system unifies the generator and the starter, thereby eliminating the traditional starter, effectively simplifying the engine accessories, reducing weight, and improving mobility and reliability. [0003] Frequency conversion AC power supply system is the focus and hotspot of research and development in the field of civil aircraft. The new frequency conversion AC power system mostly adopts a three-stage brushless AC synchronous motor, which includes a main motor, an AC exciter and a permanent magnet auxiliary exciter, and the brushless of the entire motor is realized by means o...

AI Technical Summary

Problems solved by technology

However, when the three-stage brushless AC synchronous motor is in a static state, if the AC exciter adopts constant DC excitation, the induced potential cannot be generated in the three-phase winding of the rotor of the AC exciter, and the main motor cannot obtain the excitation current, so the main motor stator The induced potential cannot be generated in the three-phase winding; if the AC exciter adopts single-phase AC excitation, the induced potential of the armature winding of the main motor is a steamed bun wave with a gap, and the rotor excitation current of the main motor cannot be directly measured

In summary, the three-stage brushless AC synchronous motor cannot directly follow the conventional rotor initial position estimation method of the electric excitation synchronous motor

At present, there are very few studies on the initial position estimation technology of three-stage brushless AC synchronous motors at home and abroad. Literature [1]~[3] proposed a three-stage brushless AC synchronous motor based on extended Kalman filter. The sensor control strategy uses the signal injection method to estimate the rotor position information of the motor at low speed, and uses the extended Kalman filter to estimate the rotor position information of the motor at medium and high speeds, but does not mention the rotor initial position estimation method when the motor is stationary; patent [4 ] also proposed a new three-stage brushless AC synchronous motor position sensorless control method, which uses the rotating high-frequency signal injection method at static and low speeds, and uses the voltage mode position estimation method at medium and high speeds, but At low speed, there is a problem of judging N and S poles, but the patent does not explain the judgment method of N and S poles

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