Automatic Generation Control Application for Transmission and Generation Centres

Abstract

Recently, a new Emergency Control Centre for Albanian Transmission System Operator (TSO), which includes Supervisory control and data acquisition (SCADA) and Automatic Generation Control (AGC) applications, has been commissioned. Nowadays, an AGC application is being prepared for the biggest generation company in Croatia, as part of control centre for hydropower plants within western part of Croatia. Both of these implementations use the same AGC application, which is presented in this paper. Although AGC for TSO and AGC for Generation Centre (GC) have many similarities, their main goals are different. AGC for TSO must mainly regulate system’s frequency and area’s active power interchange to their desired values, using only power plants engaged in load-frequency control (LFC). However, AGC for GC must ensure that power production of each power unit not engaged in LFC tracks its planned value, while also ensuring that centre’s share in LFC is being respected. Albeit the AGC is standalone application, in both afore-mentioned implementations it is affiliated with SCADA application, from which it obtains all required input measurements and indications and to which it delivers calculated setpoints. Additionally, all AGC pictures are integrated into SCADA pictures as well, in order to simplify operation and monitoring functionalities. AGC for Albanian TSO controls active power generation of six hydro power plants engaged in LFC. AGC for GC West in Croatia controls active power generation of ten hydro power plants. In both implementations, communication with remote objects is done using IEC 60870-5-104 communication protocol, while communication with other control centres is done using ICCP communication protocol. Power production plans are sent to AGC either from Market Management Systems (in TSO case) or from scheduling and optimization application (in GC case).