Study On Reactive Power And Voltage Control Strategy For Wind Farm

It brings challenges to power grid with large scale wind power integrated. The impact of wind farm to power system cannot be ignored with its increasing porpoerties in the power system. In this paper, the wind farm reactive power and voltage stability issues is studied, a DFIG power system model which considers the impact of dual PWM converter is proposed based on the commonly-used power flow calculation model and the characters of power flow of DFIG as well as the losses of dual PWM converter. Based on this model, the niche multi-objective particle swarm algorithm is used to optimisize the factor of doubly-fed wind turbine power and the voltage of reactive power compensation device. Finally, the characters of doubly-fed wind generators and static var compensator under the changing wind speed has been studied. Based on this discussion, a reactive power control strategy for the wind farm with doubly fed wind turbine is proposed.The basic concepts of double-fed wind power generation systems and components is introduced, including the components of doubly fed wind power generation system, like models of wind turbine parts and doubly-fed wind turbine section as well as converter section. The steady-state model of DFIG is introduced to illustrate the energy flow to lay the theoretical foundation for the later.Due to the inaccuracy of the DFIG internal losses taken into account for the flow calculation, a DFIG power system model which considers the impact of dual PWM converter is proposed based on the commonly-used power flow calculation model and the characters of power flow of DFIG as well as the losses of dual PWM converter. The generator stator, rotor and virtual node as well as the converters node are imported to calculate the power flow.As the double-fed wind turbine has a capacity of taking part in reactive power regulation for wind farms, based on the model for DFIG in power flow calculation, the niche multi-objective particle swarm algorithm is used to optimisize the factor of doubly-fed wind turbine power and the voltage of reactive power compensation device in order to achive the aim for reactive power optimization.For the wind energy has the features like random, intermittent and non-scheduling, a reactive power control strategy for the wind farm with doubly fed wind turbine is proposed based on the characteristics of static var compensator and DFIG.