VOLTAGE-SOURCED HVDC SYSTEM WITH MODULATION FUNCTION

摘要

PURPOSE: A voltage type super-voltage direct current transmission power system having a modulation control is provided to simultaneously control a frequency and the voltage of a system by simultaneously controlling an active power and a reactive power. CONSTITUTION: A sensor unit detects a three-phase current, a reactive power and an active power from a three phase alternating current source. A rectifier controller(27) generates a D shaft and a Q shaft signal by receiving the detected three-phase current, the reactive power and the active power. A D/Q controller(26R, 26I) generates an active power signal D shaft signal and a reactive power signal Q shaft signal by receiving the D shaft and the Q shaft signal of the rectifier controller. A PWM unit(25R, 25I) generates a calling signal which is changed a pulse width for calling the switching elements based on an output signals of the D/Q controller. The D/Q controller includes a rotary converter with generating an AC signal, a D shaft command unit and a Q shaft command unit.