Synthetic evaluation of power quality based on improved AHP and probability statistics

Power quality is represented by several indexes showing each aspects of electric energy.A series of standards are formulated in many countries,which can only judge whether each index is qualified.However,they can not reflect the nature of power quality completely,truly,and uniquely.As a result,a new method based on improved AHP and probability statistics is presented to evaluate the power quality.Firstly the judgment matrix is generated within the framework of AHP,then the weights are obtained by applying two-stage linear programming approach,different from typical eigenvector method.Finally,each index is quantified with probability statistic,based on which the unique synthetic evaluation value of power quality can be obtained.The class evaluation method is presented to evaluate the unique value.An analysis example of evaluating the power quality caused by electric railway is given.