METHOD AND APPARATUS FOR DECOUPLING THE ACTIVE AND REACTIVE POWER CONTROL FOR A HIGH VOLTAGE DC TRANSMISSION LINE COUPLING TWO NETWORKS

摘要

ABSTRACT OF THE DISCLOSUREA high-voltage d-c transmission system in which oneof the converters is operated as a rectifier and the other asan inverter. A first cascade control which sets the rectifiercontrol angle includes a superimposed active power controllerand a subordinated d-c controller. A second cascade controlwhich sets the inverter control angle includes a superimposedvoltage/active power controller, a superimposed quenching anglecontrol and a subordinated quenching angle controller. Thesetting signal of each of the two superimposed controllers arecontrolled in dependence on the control deviation of the otherone of the superimposed controllers via a first or second pilotcontrol for decoupling the cascade controls. The gain factorsof the pilot control quantities depend on the operating pointin such a manner that a small engagement of the pilot controlvariable exists for small control angles and a large engagementexists for large control angles.