Method for identifying position of rotor of brushless direct current motor

Abstract

The invention discloses a method for identifying the position of a rotor of a brushless direct current motor. The method comprises the following steps: on a stator of the blushless direct current motor, arranging a flux linkage sensor for each of three phases of windings, detecting the stator flux linkages of the three phases, and performing differentiation on the stator flux linkages of the three phases to obtain extended back electromotive forces of the three phases; detecting by a current sensor to obtain the phase currents of the three phases of the brushless direct current motor; respectively subtracting the products of the differentials of the phase currents of the three phases of the brushless direct current motor and the phase inductances of the three phases of the brushless direct current motor from the extended back electromotive forces of the three phases to obtain phase back electromotive forces of the three phases of the brushless direct current motor; calculating the angular velocity of the brushless direct current motor by using the phase back electromotive forces of the three phases of the brushless direct current motor and back electromotive force coefficients; and performing differentiation on the angular velocity of the brushless direct current motor to obtain the position of the rotor of the motor. With the method disclosed by the invention, the problem that the position of the rotor of the motor is difficult to identify accurately in time in high-performance control of the brushless direct current motor can be solved; the advantages of need of less motor parameters, simple structure, small calculations, high identification accuracy and good timeliness.

Description

technical field [0001] The invention belongs to the field of brushless direct current motor control, relates to a brushless direct current motor, in particular to a method for identifying the rotor position of a brushless direct current motor. Background technique [0002] Brushless DC motors have many advantages such as simple structure, high power density, and simple control. In recent years, brushless DC motors have been increasingly widely used in industrial fields such as high-performance speed regulation systems and servo control systems. [0003] In the closed-loop control of brushless DC motor, the identification of rotor position has an important influence on the stable operation of the motor. If the identification of the rotor position is inaccurate, it will lead to poor speed regulation accuracy of the brushless DC motor, poor servo effect, and in severe cases, the brushless DC motor will not operate normally. At present, the known prior art, one is to use variou...

AI Technical Summary

Problems solved by technology

If the identification of the rotor position is inaccurate, it will lead to poor speed regulation accuracy of the brushless DC motor and poor servo effect, and in severe cases, the brushless DC motor will not operate normally

At present, the known prior art, one is to use various sensors such as Hall sensors and photoelectric encoders to detect the position of the motor rotor, but this method has high hardware costs and will reduce the reliability of the motor control system; another method uses motor The voltage and current signals are used to observe the rotor position of the motor through various observer methods, but the algorithm of this method is often very complicated and difficult to be practically applied

[0004] Therefore, there are many problems in the rotor position identification effect of the prior art, and it is difficult to meet the closed-loop control requirements of the brushless DC motor.

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