Sensorless control method for switched reluctance motor based on virtual flux linkage and single-phase current detection

Abstract

The invention provides a sensorless control method for a switched reluctance motor based on virtual flux linkage and single-phase current detection. The method comprises the steps of assuming that theconduction sequence is A, B and C, and firstly giving a turn-off angle [theta]off, a direct-current bus voltage Ubus, power switch voltage drops US1 and US2 and diode voltage drops UD1 and UD2; calculating a virtual flux linkage [lambda]vir of the phase A through a virtual voltage Uvirtual and the current of the phase A, and estimating a reference flux linkage [lambda]ref(30 degrees, i) and a reference flux linkage [lambda]ref([theta]off, i) at the positions of 30 degrees and [theta]off; comparing the [lambda]vir with [lambda]ref(30 degrees, i) and [lambda]ref ([theta]off, i), and determininga turn-off angle position and a commutation position; estimating a reference flux linkage [lambda]ref ([chi], i) from the misalignment position to the middle position [chi] of the alignment position,and estimating the rotating speed of the motor; and generating a three-phase trigger pulse signal by adopting a delay time strategy according to a falling edge pulse of the current phase driving signal and a rising edge pulse of the next phase driving signal, and further controlling the switched reluctance motor. According to the invention, a single-phase current sensor and a delay strategy are adopted to generate the three-phase trigger pulse signal, so that the motor is controlled, and the cost is reduced.

Description

technical field [0001] The invention relates to the technical field of high-speed position sensorless algorithms in switched reluctance motors, in particular to a position sensorless control method for switched reluctance motors based on virtual flux linkage and single-phase current detection. Background technique [0002] SRM (Switched Reluctance Motor) has a solid construction, low cost, high efficiency and fault tolerance. All these inherent advantages have attracted increasing attention, and SRM has become an attractive option for many industrial applications and wind power generation. However, accurate position detection is very important for the control of SRM. Rotor position information is usually obtained through mechanical sensors (such as optical encoders and Hall sensors) fixed on the motor during operation, which reduces the reliability of the motor and increases the cost; at the same time, these position sensors cannot be used in harsh environments Accurate de...

AI Technical Summary

Problems solved by technology

[0004] The position sensorless control methods in the prior art can be mainly divided into two categories: the method based on the non-energized phase and the method based on the energized phase. These two types of methods generally require three-phase current and voltage sensors, and the operating cost is relatively high.

Images