Traditional control strategy chooses four power components from six ones to calculate the reference current signals in synchronous rotating frame when the grid voltage is unbalanced and it leaves the rest of the power components uncontrolled. The instantaneous power model based on generalized reactive power in two-phase stationary frame is built to solve the above problem. The four reference current signals were derived through four power components in stationary frame, so the average value and the secondary fluctuations of active and reactive power were controlled simultaneously. Park transformation and phase-locked-loop (PLL) were omitted and complexity is reduced with the proposed method. Therefore, the dynamic performance was improved as well. Taking PWM rectifier as research object, simulation and experiment were carried out to verify the validity. The results showed that the secondary fluctuations of dc-side voltage were suppressed and the system can operate at unity power factor.
