A Novel Strong Robust Current Control Method for Brushless DC Motors

Abstract

The invention relates to a novel brushless direct-current motor high-robustness current control method. The method includes the following steps that: present Hall periodic current is set to flow from an x phase to y phase, and reference voltage under an ideal condition is calculated through utilizing the resistance and inductance parameters as well as reference current and a linear counter electromotive force of a motor; the change rate of an estimation parameter in a unit control period is calculated through utilizing the differences of the reference current, the actual forward current ix, the reference voltage and the linear counter electromotive force, and the estimation parameter is calculated according to the previous values of the estimation parameter; continuous control quantity is calculated according to the estimation parameter; and on-off gain k and on-off control quantity k.sgn(s) are calculated through utilizing the errors of the actual forward current and the reference current and according to the adaptive laws of high-frequency on-off gain, wherein s is a sliding mode surface which is designed according to current errors; and output voltage of the novel brushless direct-current motor high-robustness current control method can be obtained according to the continuous control quantity ucn and the on-off control quantity k.sgn(s). The novel brushless direct-current motor high-robustness current control method of the invention can be applied to brushless direct-current motor high-performance control application occasions under harsh environments.

Description

technical field [0001] The invention relates to a control method of a brushless direct current motor. In particular, it relates to a novel strong and robust current control method for brushless DC motors. Background technique [0002] Permanent magnet brushless DC motors have been widely concerned in industrial applications due to their high efficiency, high power density, high stability and simple structure. Because in the actual control system of permanent magnet brushless DC motor, the change of resistance and inductance and the nonlinear characteristics of the switching tube in the inverter make it a nonlinear time-varying system with parameter changes and unmodeled disturbances, so the design A high-performance robust current controller is very necessary to ensure the smooth output and fast tracking of the motor torque. [0003] Adaptive control algorithm can effectively solve the influence of parameter uncertainty on current control through parameter estimation. How...

AI Technical Summary

Problems solved by technology

However, the dynamic response of the adaptive current control is poor, and the high-frequency vibration of the current is generated in the steady state of the sliding mode current control. Although the adaptive robust current control has improved the above deficiencies, its constant high-frequency gain still cannot meet the requirements. High-performance control requirements under different loads and operating conditions

[0006] For the adaptive adjustment of high-frequency gain, the traditional method can only adjust the high-frequency gain in one direction, that is, this parameter can only be increased but not decreased

In recent years, an adaptive law of two-way regulation has been proposed, but it depends on the motor parameters and the high-frequency gain cannot be stabilized at the desired value when the motor is running stably.

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