A method for electrical network voltage compensation without PLL based on coordinate transformation

To real time detect the positive sequence of fundamental waveform is key technologies for power quality compensating mechanism. The three-phase positive sequence detecting method without phase lock loop (PLL) based on the dq0 coordinate transformation was put forward in this paper. To design control system of series voltage compensating mechanism with the method, the equipment can well achieve wave compensation of input voltage in public node, and constant voltage modulation of output voltage in a small area.