The theories in the fiver phase hybrid motor microstepping drive system with fixed hysteresis band current controlled SPWM technique are analyzied .

The nonlinear decoupled control、MPPT technology、space vector PWM control、current tracking method are adopted in system,it can adjust power factor on grid,and have wide voltage r.

Aiming at the shortcomings of PI controller,this paper engaged in improving the control of photovoltaic grid-con-nected inverter and put forward a current tracking control strategy which combines PI control with repetitive control.

Taking a new injection type hybrid active power filter as an example, this paper proposes a new technology for eliminating switching ripples with adopting the synthesis control algorithm for current tracking, attaching the SVPWM based on random PWM and installing the output filter desig.

Research on control system of matrix converter with current track control based on dSPACE;

With the mathematic model of shunt APF in three-phase stator coordinates set up in this paper, it is found by calculation analysis that there is a period disturbing signal in the current closed loop transfer function of the general PI control, and the disturbing signal influences the performance of current track distinctly.