| The Automatic Generation Control (AGC) loop in a multi-machine power system is responsible for maintaining the frequency of the system. The AGC provides regulating pulses to the governors of the generators through the power system control center. The governors adjust the valve positions according to the regulating control signal which alters the power of the prime movers to restore and maintain correct frequency, as required. Machine speed deviations are used for calculation of the regulating signal. In current practice, the system frequency is controlled using a central controller. The control center receives frequency (or speed) measurements from major generators and calculates a single frequency called the Center of Inertia Frequency which is used for the calculation of the regulating signals through an Integral Control.;This thesis proposed a decentralized frequency control scheme by applying local controls for each machine that used the frequency measurements from FNET. Instead of using the frequency of major generators in the area through the central controller (which is the present practice), the use of wide area frequency measurements was suggested in this study. Wide area frequency measurements are available from the Frequency Monitoring Network (FNET) system. The FNET system is a new concept and is presently being developed and installed within power systems. The performance of the decentralized frequency controller is evaluated through computer simulation of IEEE test systems.;Simulations were done using PSS/E, a power system software package commonly used in the industry. The performance of the decentralized frequency control scheme using frequency information from FNET was tested and compared to the traditional method for different disturbances (or faults) using primarily the IEEE 118-bus Test System. Results showed that application of wide-area frequency information from FNET in decentralized frequency control is more effective than the traditional method for all of the fault cases. |
