Improved one-cycle control algorithm for diagnosis and optimization in low-voltage SVG device

Nowadays low voltage SVG (Static Var Generator) has got a certain amount of practical applications. Current PWM control is a key unit of SVG control process. Taking the three-phase four-leg inverter for research object, this paper designs the current controller base on one-cycle control algorithm and derivates the control equation in detail. Aimed at the problem of control shocks existing in traditional one-cycle control, the improved control unit is given out with the fundamental positive sequence active component of load current as control objectives. This improved control unit could realize reactive power, harmonics, and negative sequence imbalance current comprehensive compensation function, and duty cycle stability are improved. Control performance and response time of the control unit were significantly optimized. The proposed improved one-cycle control unit was validated in terms of simulation and experiment result, and has high practical value of low-voltage SVG application.