Brushless direct current motor sensorless model prediction control system and control method

Abstract

The invention discloses a brushless direct current motor sensorless model prediction control system and control method, and relates to the field of motor control. The invention aims to solve the problems of position detection and overlarge torque pulsation in the operation process of the existing brushless direct current motor. The method comprises the following steps: collecting bus voltage, phase current and counter electromotive force of the brushless direct current motor, obtaining the rotor position according to the counter electromotive force, and an extra position sensor being not needed; generating a current control signal according to the given rotating speed and the feedback rotating speed; and selecting a corresponding prediction control model according to the signals collectedby the sampling module, and outputting PWM signals with adjustable duty ratios to control the power converter. A proper control signal is output according to the commutation position of the motor, andthe current fluctuation of the motor is reduced, so that the torque ripple of the brushless direct current motor is reduced.

Description

technical field [0001] The invention relates to the field of motor control, in particular to a model predictive control system and control method for a brushless DC motor without a position sensor. Background technique [0002] In recent years, brushless DC motors have rapidly gained widespread attention due to their reliable operation and wide range of speed regulation. However, due to the existence of the position sensor and the problem of torque ripple, the application in high-precision occasions is limited. The operation and control of brushless DC motors require real-time and accurate rotor position information, which is usually given by position sensors. The existence of position sensors will inevitably lead to problems such as increased lead wires, increased motor volume, and increased costs. At the same time, due to the mechanical structure of the brushless DC motor and the existing electronic commutation problems, the torque ripple phenomenon occurs during the rota...

AI Technical Summary

Problems solved by technology

However, due to the existence of the position sensor and the problem of torque ripple, the application in high-precision occasions is limited

The operation and control of brushless DC motors require real-time and accurate rotor position information, which is usually given by a position sensor. The existence of a position sensor will inevitably lead to problems such as increasing the number of lead wires, increasing the size of the motor, and increasing the cost.

At the same time, due to the mechanical structure of the brushless DC motor and the existing electronic commutation problems, the torque ripple phenomenon occurs during the rotation of the motor, and the harmonic torque ripple and cogging torque ripple generated by its own mechanical structure are very small. However, the commutation torque ripple caused by electronic commutation is relatively large. This is because during the commutation process of the motor, there is a process of increasing the current of the open phase and a process of synchronously decreasing the current of the closed phase. When the changes of the two-phase currents are inconsistent, it will Cause non-commutated phase current fluctuations, resulting in brushless DC motor commutation torque ripple

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