Torsional torque suppression of decentralized generators using H∞ observer

The output power fluctuation of renewable energy power plants such as wind turbine generator and photovoltaic system result in frequency deviation and terminal voltage fluctuation. Furthermore, these power fluctuations also affect the turbine shafting of diesel generator and gas-turbine generators which are the main power generation systems in isolated islands. This paper presents a control strategy that achieves torsional torque suppression and power system stabilization. Since the measurement of the torsional torque is difficult technically, and there is uncertainty in mechanical constants of the shaft torsional system, the torsional torque is estimated by using developed H_infin. The simulation results validate the effectiveness of the proposed control system.