An Improved Three-Phase Current Reconstruction Strategy Using Single Current Sensor with Current Prediction

In traditional current reconstruction method with single current sensor, the SPWM duty range was limited inevitably. In order to improve the utilization of dc-link voltage, this paper proposed an improved SPWM modulation method with dynamic bias compensation. Regarding the problem of phase current sampling asynchronous and the digital control delay, which undermines the performance of current loop control, especially at low carrier rate state, the Lagrange interpolation method is employed to achieve the phase current prediction. Validations are carried out by the PMSM FOC system built in Matlab/Simulink.