Research On The Control Of High Performance For Permanent Magnet Synchronous Motor Without Position Sensor

The speed regulation systems of permanent magnet synchronous motor are being widely used.As the motor speed regulation system which under overmodulation running state has a large output voltage,the voltage will be more easily saturated,then causes oscillating current response and reduce the response of the control system.The interference of harmonic components is one of the main problems affecting the control system of permanent magnet synchronous motor under overmodulation operation,it will directly affect the estimation accuracy of rotor position information.In the case of using sensorless control system,the estimation error of position information will directly affect the dynamic stability of the system.In this paper,a control method without position sensor is proposed,which can maintain the output amplitude unchanged and improve the output characteristics of the inverter under the condition of overmodulation.In this method,the d-axis voltage priority control strategy is adopted,and the amplitude compensation is used to output a given signal of inverter modulation with constant amplitude and small phase angle deviation.As a result,the minimum loss of output voltage of the inverter is guaranteed under over-modulation condition,and the good operation condition of inverter in overmodulation region is satisfied.An anti-windup sensorless control system based on harmonic component compensation is proposed to avoid voltage saturation under over-modulation condition.By making full use of the inverter’s own capacity,compared with the permanent magnet synchronous motor speed control system which only considers harmonic component compensation,the proposed control algorithm which based on the proposed d-axis priority is able to output an information response critical to the output voltage saturation limit in order to achieve a more efficient speed response.After avoiding the interference of the output voltage and current which form both harmonic components and voltage saturation problem,a stable sensorless control system is designed to obtain rotor position information.In the actual position estimation operation,based on the extended counter electromotive force algorithm,taking the harmonic component and the fundamental component into consider at the same time and then introduce a state observer to realize a good rotor position estimation under over-modulation condition.In the Matlab/Simulink environment,the sensorless speed regulation system of permanent magnet synchronous motor is studied by a simulation experiment.The simulation results show that the sensorless anti-windup control system can run stably under over-modulation condition.The error of rotor position estimation caused by harmonic current and voltage is avoided,the speed adjustable range of permanent magnet synchronous motor is widened,the feasibility and effectiveness of the designed control system are proved.