Method for detecting load unbalance of brushless DC motor

Abstract

The invention discloses a method for detecting load unbalance of a brushless DC motor. The method comprises the following steps of: collecting a speed signal and a phase voltage signal of the brushless DC motor; integrating a historical acquisition value with a target speed signal through two processes of a fuzzy controller; establishing a corresponding fuzzy decision table; realizing an intelligent judgment and a decision of the load unbalance. According to the method for detecting the load unbalance of the brushless DC motor, the distortion data of interference signal and variation data of stepless speed regulation are eliminated, the error detection of the load unbalance is eliminated, the traditional detection device for high current is not required, and the safety of the system is improved. The invention is a method for detecting the dynamic load imbalance of the brushless DC motor which is low in cost, simple and accurate in detection, and easy to realize.

Description

technical field [0001] The invention relates to the field of motor control, in particular to a method for detecting load unbalance of a permanent magnet brushless DC motor. Background technique [0002] With the maturity of electric motor technology and the development of motor control technology, high-efficiency and energy-saving products are more and more widely used in the industrial drive industry and household appliance industry. Traditional three-phase AC asynchronous motors, single-phase AC capacitor motors, and shaded pole motors It is difficult to meet the requirements of modern products for low-power green energy, high efficiency, stepless speed regulation, small size and long life. The development of permanent magnet brushless DC motors and permanent magnet synchronous motors has increased significantly. trends, especially in white goods such as washing machines, refrigerators and air conditioners. However, if the permanent magnet brushless DC motor drives the lo...

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Problems solved by technology

The unbalance detection method based on the motor speed is difficult to match the internal PI adjustment parameters of the controller with the complex oscillation of the system, and it is difficult to stabilize the output of the system. If the error of the detection result is too large, the control will fail or the expected control effect will not be achieved; The unbalance detection method of motor power and current requires a special hardware detection circuit. The detection device is affected by the large current and the impact of the load, and its detection accuracy decreases and drifts, which affects the stability of the detection and control system. It consumes a certain amount of power consumption, increases the temperature rise of the components inside the control system, and has a certain impact on the life of the product; the unbalance detection method based on the output signal of the inverter PI controller is a very good low-cost detection method, but Its drive control method is limited to frequency converter drive, but cannot realize the dynamic load unbalance (OOB) detection of permanent magnet brushless DC motor

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