Research On Comprehensive Evaluation And Control Of Power Quality For Shujia Mountain Wind Farm

With the growing demand for energy and the drying up of traditional resources such as oil and coal,the energy problem has become a great challenge that mankind has to face.As an inexhaustible clean energy,wind energy is currently the most mature technology with widely used and commercial potential for the new energy industry in the world,and it has got greatly development in recent years.But in practical application,wind resources show significant randomness and volatility and make wind power in the grid operation difficult to control,which will affect the power quality and limit its application level.How to evaluate and manage the wind farm scientifically and rationally has attracted more and more attention.Aiming at the comprehensive evaluation of wind farm power quality,the power quality index system of wind farm is established based on four individual indexes of voltage deviation,voltage fluctuation and flicker,harmonic and three-phase unbalance.In the basis of traditional analytic hierarchy process,adopt the method for the combination of subjective and objective weights and introduce the method of grey correlation analysis,making the power quality comprehensive evaluation method more reasonable.The method solves the subjectivity of weight coefficient for traditional methods while eliminating the contrary of practical importance for objective weighting method.The wind power quality comprehensive evaluation method is applied to the Shu Jia mountain wind farm,the evaluation grade and comparison of three power supply schemes are gotten,which demonstrates effectiveness of evaluation method.Aiming at the comprehensive evaluation of wind farm,the power quality control scheme of wind farm is proposed combining static var compensator and hybrid filter from two aspects of reactive power management and harmonic wave governance.This scheme not only can restrain harmonics,but also can compensate reactive power and reduce the cost of operation.According to the principle of reactive power compensation allocation of wind farm,the calculation method of capacity allocation of static var compensator(SVC)is given.as research samples,It is proved that the static var compensator and hybrid filter system can effectively compensate reactive power and restrain harmonic current injected into the power grid through the simulation analysis of power quality optimization scheme in Shu Jia mountain wind farm.