STABILITY STUDY OF A MULTI MACHINE SYSTEM USING MODIFIED ROBUST CO-ORDINATE AVR AND POWER SYSTEM STABILIZER

Modern power system is a complex network. Rapid industrialization & globalization makes the network management more complex. The stability of power system becomes a more critical challenge because a cost of a voltage collapse or instability could cause power interupti0n that could have very high impact on economy. As network expands, generating station in one cluster& the neighboring cluster can develop oscillatory tendencies under disturbance. This depends on relative strength of the group of generators& the interconnecting network. The generator could be of different make, different size & different type of excitation & governor control. This adds to the complexity of the system as response of different generators could be different. The exhibits low damping to certain disturbances & resulting oscillation could lead to instability. Power system stabilizers provide an effective means of improving system damping of electric power system during low frequency oscillations in the range of 0.5 to 3HZ.Low frequency oscillations are a common problem in large power system. Low frequency oscillations are observed when large power systems are interconnected by relatively weak tie lines. These oscillations may sustain & grow to cause system separation if no adequate damping is available. Excitation control or AVR is well known as an effective mean to improve the overall stability of the power system. This work is an effort to ensure quality power to the consumers efficiently by using Robust-co-ordinate AVR-PSS (RCAP). This work presents the stability study of a Multimachine system using Robust AVR& PSS.