An analytical approach for LQR design for improving damping performance of multi-machine power system

In a multi-machine environment, the inter-area low-frequency oscillations induced due to small perturbation(s) has significant adverse effect on maximum limit of power transfer capacity system. Conventionally, address this issue, systems were equipped with lead-lag system stabilizers (CPSS) for damping low-frequency. recent years research was directed towards optimal control theory design an linear-quadratic-regultor (LQR) stabilizing against perturbation(s). The provides systematic way LQR sufficient stability margins. Hence, improved level performance than CPSS over broad-range operating conditions. process designing involves optimization associated state (Q) and (R) weights. This paper presents analytical approach (AA) by deriving algebraic equations evaluating elements weight matrix ‘Q’. proposed is studied IEEE test comprising 4-generators 10-busbars.