CONVERTER CONTROL APPARATUS FOR AC-DC PARALLEL POWER TRANSMISSION SYSTEM

摘要

CONVERTER CONTROL APPARATUS FOR AC-DC PARALLEL POWER TRANSMISSION SYSTEM A phase locked oscillator in phase with the AC voltage at a connecting point between a direct current power transmission system and an alternating current power transmission system of an AC-DC parallel power transmission system is provided in order not to loss the phase signal of the AC voltage at the connecting point at the time of occurrence of a fault in the power system. A firing signal continues to be applied to the converters of the direct current system during the presence of the fault on the basis of the phase signal produced from the oscillator. With the elimination of the fault, the power transmitted through the direct current power transmission system is increased as far as possible to attain the greatest possible stability of the AC-DC parallel power transmission system. The transmitted power is restored to its steady state when the phase difference between the AC voltages at the ends of the AC-DC parallel power transmission system begins to be reduced.