| 摘要 |
PURPOSE: A digital phase controller of an HVDC(High Voltage Direct Current) system is provided to normally operate by inputting at least one signal among the three phase alternating current voltages. CONSTITUTION: A digital phase comprises a voltage measurement part(110), a level director(115), a phase limit block(120), an oscillator(125), an alpha balancing block(130), a gamma balancing block(135), and a ring counter(140). The digital voltage measurement part measures the three phase AC(Alternating Current) voltage, makes six pulses having the phase difference of 30 degree, and measures the level of the voltage. The phase limit block measures an alpha value and a gamma value by using a timing signal outputted from the voltage measurement part and generates a counter gate pulse. The phase limit block generates a reset suppression signal and an imperative reset signal. The oscillator generates a firing pulse through a loop error inputted from the outside. The ring counter uses the firing pulse inputted from the oscillator depending on the selection of a control mode and generates the firing signal to a 12 valve. [Reference numerals] (110) Voltage measurement part; (115) Level director; (120) Phase limit; (125) Oscillator; (130) Alpha balancing block; (135) Gamma balancing block; (140) Ring counter; |
