The Research On Operating Evaluation Of Reactive Power And Voltage Auto-control System

With the rapid development of Tianjin Grid, automatic voltage control(AVC) has acted as one effective means to ensure grid safety as well as economical operation. In order to make full use of AVC as well as enhance the control effect, it's of high need to run accurate quantitative estimation on AVC's control performance with the trend of its expanding control areas.Based on the traditional review for AVC in the electric farm side, the quantitative analysis strategies for AVC performance applied in the grid are studied and an evaluation system is put forward which can be divide into two aspects, i.e. the control performance review and loss reduction analysis. For the former part, a new review method is presented based on the “two principles” regulations where basic review ways of reactive power and voltage control for electric farms are recorded. It not only bring forward the review strategy for the AVC subsystem of the 220 kV centralized control substation, but also lower AVC subsystem, thus evaluating AVC system comprehensively. As for the latter part, the paper is organized as below. First, online theoretical line loss calculation on account of real-time state estimation is discussed followed by a method proposed to model statistic area for the online loss automatically and a way to store and statistic loss electrical energy automatically based on database triggers. Second, online continual power flow is used to calculate the AVC loss reduction effect, which can obtain the reduced loss energy real-time after AVC runs in closed-loop mode so that the economic benefits can be calculated quantitatively and guidance for operators to optimize and enhance the control strategy can be generated.The methods proposed have been successfully applied in Tianjin Power Grid Dispatch Center in the form of software system which is aimed to evaluate AVC. It has been proven a good tool to evaluate AVC control performance as well as loss reduction effect quantitatively and provide a scientific reference for operators to analyze and optimize AVC control strategies.