Automatic control system (ACS)

ACS (РТУ-ХХХХХХ/YYY) УХЛ4 is an automatic control system designed for automatic control of controlled shunt reactor (CSR) inductance by means of semiconductor converters (SCs) which form the reactor bias current for the purposes of stabilizing the voltage in high-voltage (35 to 500 kV) power network or for compensating excessive charge capacity of power lines; for preliminary biasing the reactor and ensuring dynamic modes; and for switching the reactor to idle mode in case of emergency or overloads, or for smooth CSR inductance control in manual mode.

According to the above purpose, ACS is capable of performing the following:

• CSR inductance automatic control within the pre-set limits for the purposes of stabilizing the voltage on sub-station buses;
• Ensuring CSR current manual control mode through step-wise delay angle change by SC thyristors;
• Automatic maintenance of the pre-set value of reactor power winding current;
• SCR switching from automatic to manual control mode and back;
• Indication of mode parameters, control set-points and complex circuit condition;
• Alarm in case of overload and damage in SC converter;
• CSR power winding current overload control with subsequent automatic power limitation and alarm;
• Converters overload and overheating control with subsequent power limitation and alarm;
• Converter thyristor control checking;
• Implementation of control actions from external protection and automation devices;
• Ensuring SCR preliminary biasing mode.