Manner for the voltage control in transformation equipping and direct current link

摘要

PROBLEM TO BE SOLVED: To provide a simple, satisfactory method capable of maintaining the voltage of DC links within a safety operation limit even under an abnormal state and a control system for performing the method.;SOLUTION: Converting facilities (STN1, STN2) having voltage-converting devices (CON1, CON2) are provided between DC links (W1, W2) and AC networks (N1, N2) of a high voltage DC transmitting system. Control systems (CTRL1, CTRL2) of the converting facilities have means for controlling a dynamic electric power flow (P) between the DC links and the AC networks by having an effect on phase difference (γ) between the bus voltages (UL1, UL2, UL) of the AC networks and the bridge voltages (UV1, UV2, UV) of the voltage- converting devices. The control systems have a detecting means (48) that generates a phase change command signal (PCO) based on an abnormal voltage state index at the DC links, and a control means (49) that has effect on the phase of the bridge voltages based on the phase change command signal and control, in such a way that the phase difference between the bridge voltages and the bus ones becomes the electric power flow from the DC links to the AC networks.;COPYRIGHT: (C)2002,JPO