Decentralized Synergetic Power System Stabilizer

This paper presents a decentralized synergetic power system stabilizer (DSPSS). The nonlinear control law was synthesized by introduction of invariant manifolds into the state space of studied system, synchronous machine connected to infinite bus. The invariant manifold was defined as a linear combination of the generator terminal voltage, rotor speed and active power deviation to achieve coordination of the synchronous generator electromechanical oscillation damping and terminal voltage control. Compared to other synergetic power system stabilizers, this one uses real time Park’s transformation to calculate dq-components of generator currents and voltages. Also, a novel approach for calculation of a generator voltage derivative is presented, and the proposed stabilizer is less sensitive to sudden voltage changes and measurement noise. DSPSS control law was implemented on real-time hardware platform and experimentally tested on an 83kVA synchronous hydrogenerator. Experimental results for the power and voltage reference step change, loss of the transmission line and three phase short circuit were conducted using DSPSS and PSS2A stabilizers. Furthermore, the results showed that the proposed DSPSS stabilizer was robust to system parameter changes and has better dynamic response than the classic PSS2A in case of small and large disturbances.