Damping Controller Design in VSC HVDC base on Offshore Wind Power Plants to Improve Power System Stability

Because of low losses and voltage drop, fast control of power, limitless connection distance and isolation issues, using high voltage direct current (HVDC) transmission system is recommended to transfer power in the power systems included wind farms. This paper aims to propose a supplementary damping controller(SDC) based on the HVDC transmission systems to improve not only power system dynamic stability but also energy conversion efficiency and torsional vibration damping in the wind power plants(WPPs). When the WPPs are working in power control mode, the active power is set to its reference value which is extracted from power-speed curve. This paper shows that torsional oscillations associated with the poorly torsional modes in the hybrid power system can be affected by different operating regions of the power-speed curve of WPP. Therefore, it is essential to employ a SDC to have the optimum energy conversion efficiency in the wind turbine and the most dynamic stability margin in the power system. The SDC is designed using a fractional order PID controller (FOPID) based on the multi-objective bat-genetic Algorithm (MOBGA). The simulation results show that the proposed control strategy effectively works in minimizing the torsional and electromechanical oscillations in power system and optimizing the energy conversion efficiency in the wind turbine.

Keywords:

component , Energy Conversion Efficiency , Wind Turbine , HVDC , Supplementary Damping Controller , Bat-Genetic Algorithm.