Compensation calculation method of heavy load phase of brushless direct current (DC) motor without position sensor

Abstract

The invention relates to the technical field of brushless direct current (DC) motors, and in particular relates to a compensation calculation method of the heavy load phase of a brushless DC motor without a position sensor. The method is characterized by adopting a back electromotive force detection method to detect the three-phase terminal voltage with a back electromotive force detection circuit, carrying out depth filtering with a filter circuit, comparing the voltage with an analog neutral point, generating a rotor position signal with a digital signal processor (DSP), dividing the terminal voltage into a back electromotive force signal and a follow current interference signal, calculating the phases and amplitudes of the two signals to obtain a phase advance angle, caused by the follow current, of the rotor position signal and compensating the phase advance angle. The method has the following beneficial effects that: the controller can determine the phase advance angle in real time by only detecting the phase current of the motor; and phase angle compensation can be appropriately carried out according to the current and the rotating speed as the advance phase change of the phase angle is beneficial to the reduction of the torque ripple of the brushless DC motor, thus ensuring the motor to reach the best operation state.

Description

technical field [0001] The invention relates to the technical field of brushless direct current motors, in particular to a calculation method for heavy-load phase compensation of a position sensorless brushless direct current motor. Background technique [0002] Brushless DC Motor (Brushless DC Motor, hereinafter referred to as BLDC) has been fully developed in the world due to its high reliability, high efficiency, convenient speed regulation, and long life. In some more developed countries, brushless DC Electric motors will become the dominant motor in the next few years and gradually replace other types of motors. [0003] BLDC drive control methods are divided into two types: position sensor type and position sensorless type. The existence of the position sensor will bring a lot of defects and inconvenience to the application of the brushless motor. First, the position sensor will increase the volume and cost of the motor; secondly, connecting many position sensors will...

AI Technical Summary

Problems solved by technology

Its shortcoming is: by detecting the three-phase terminal voltage, performing deep filtering and then comparing with the analog neutral point, the rotor position signal is generated, but due to the large current and long freewheeling time under heavy load, it will affect the "ideal" The voltage waveform of the three-phase terminal causes waveform distortion, which affects the accuracy of the detected position signal, cannot ensure the correct commutation, and the phase angle delay commutation is not conducive to reducing the torque ripple of the brushless DC motor

[0007] Therefore, this is also the main technical difficulty in the application of the position sensorless control method in the high-power field

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