Co-ordinated multimachine PSS design using both speed and electric power

The control signals required for supplementary stabilisation of interconnected multimachine power systems are simultaneously derived from Δω, ΔP_e, the incremental speed and electrical power, respectively, of the machines concerned. Individual Δω and ΔP_e stabilisers are designed and their outputs are mixed in appropriate proportions that are added to the corresponding machine terminal voltage reference to make the power system stable and robust. Appropriate weights for decentralised stabilisers are estimated using a parameterisation technique which assures adequate damping of all mechanical modes for each of the plants being controlled. As an illustration, the proposed method has been applied to a simulated single machine infinite bus and a multimachine system for performance evaluation