Optimization of V/F Control Strategy for Asynchronous Motors
Based on the traditional VF control algorithm, this paper proposes a VF control strategy optimization scheme including pre-excitation, stator current suppression and resonance suppression. Pre-excitation can increase the torque output at the moment of motor starting; through the current suppression function, the current amplitude during motor starting can be limited to avoid overcurrent trip; the resonance suppression function can eliminate the oscillation phenomenon of the motor in certain frequency bands. Both simulation and experiment prove the correctness and effectiveness of the above algorithm.
1 Introduction
Inverter drive control is generally divided into VF open loop control, vector control and direct torque control. VF control belongs to open-loop control, the control algorithm is simple, the implementation cost is low, the motor parameters are not dependent, and the system has high robustness, but the speed control accuracy is not high and the dynamic response is slow. Vector control can realize decoupling control of magnetic flux and torque by rotating coordinate transformation, so that AC motor has excellent control characteristics like DC motor, and the speed control precision is high, but this control method is greatly affected by motor parameters. The direct torque control is to keep the stator flux amplitude constant, and directly control the electromagnetic torque by controlling the motor load angle, which has a fast dynamic response.
Compared with vector control and direct torque control, VF control has a certain gap in the speed control accuracy and dynamic response speed. However, due to its simple implementation method, low cost, high robustness, and AC speed regulation. The field still has a very wide range of applications. In addition, from the perspective of system versatility, VF control is also the most basic and applicable control method in the field of AC variable frequency drive. Therefore, on the basis of the traditional VF control method, the improvement and optimization of the control strategy has reduced or compensated for its shortcomings in control accuracy and response speed, which has become an important task. In this paper, a control strategy for optimizing VF control performance through pre-excitation, stator current suppression, resonance suppression and other functions is proposed. The control strategy is analyzed and verified by simulation and experiment.
Please pay attention to 6v Gear Motor
