1.State Grid Jibei Electric Power Company Limited Research Institution (North China Electric Power Institution Co., Ltd.), Beijing 100045, China;2.Grid-connected Operation Technology for Wind-Solar-Storage Hybrid System State Grid Corporation Key Laboratory, Beijing 100045, China;3.College of Information and Electrical Engineering, China Agricultural University, Beijing 100083, China
The wind power in China mostly adopts the mode of concentrated development in large-scale and long-distance transmission and there are often no local loads in the wind power integrated areas. Therefore, three-phase voltage unbalance frequently occurs in the areas with large-scale integration of wind power, which can cause wind turbines to disconnect from the grid in severe cases, threatening the safe and stable operation of the power system. In response to this problem, the voltage unbalance mechanism and suppression strategy in the areas with integration of wind power are proposed. Firstly, key features of voltage unbalance phenomenon in the areas with integration of wind power are extracted based on the actual data. Secondly, the equivalent circuit model is constructed in the areas with integration of wind power. Considering the static voltage stability limit and unbalanced three-phase impedance of untransposed transmission line, a method for estimating the voltage unbalance factor (VUF) is proposed. Finally, with the objective of minimizing the negative sequence voltage of the integrated substation, a three-phase reactive power optimization model for the areas with integration of wind power is proposed, and the negative-sequence voltage suppression in the areas with integration of wind power is achieved through adjustment of the dynamic reactive power compensation device to each phase. Taking the actual wind power integration system as an example, simulation analysis verifies the effectiveness of the mechanism analysis and suppression strategies.
This work is supported by National Key R&D Program of China (No. 2016YFB0900500) and State Grid Corporation of China (No. 4000-202014051A-0-0-00).
|||LIU Hui, CHEN Can, JU Yuntao, et al. Characteristics Analysis and Suppression Strategy of Voltage Unbalance in Areas with Integration of Wind Power[J]. Automation of Electric Power Systems,2021,45(14):132-139. DOI:10.7500/AEPS20200702001|