Control device for voltage-source converter that obtains DC from polyphase AC

摘要

PROBLEM TO BE SOLVED: To provide a controller for polyphase power supply voltage type converter in which the output voltage follows up a predetermined level and the power factor angle of power supply is matched with a predetermined value. SOLUTION: A DC controller 8 calculates an AC effective power command value P* and a reactive current command value calculating means 9 calculates an AC reactive power command value Q*. First and second means 1, 2 determine the difference sP, sq between the command values P*, Q* and effective power P and reactive power Q. A third means 3 calculates equivalent input vectors Ueq p , Ueq q being determined by circuit parameters, power supply voltage and power value. A fourth means 4 calculates control input vectors V0 Up , V0 Uq . Fifth and sixth means 5, 6 decide the polarity of V0 Up -Ueq p , V0 Uq -Ueq q and the control difference sP, sq . Based on decision results, a seventh means 7 selects a switching vector (u) and turns the semiconductor switch 12 in a polyphase voltage type converter on/off.