Application And Study Of STATCOM In Urban Substations

With the rapid increase of consumption loads and development of city, a number of substations with voltage level at 110kV and above 110 kV are put into operation in the urban center. With the expansion of city, many suburban substations were also incorporated into downtown substations system lead to the increasing number of urban substations. The electric power quality and the environmental influence of urban substations are put forward higher request. However the large amount of incoming and outgoing cables cause the high charging reactive power. Traditional methods of compensation of reactive power, mainly configured with fixed capacitors and reactors, can’t compensate reactive smoothly and operate with excessive noise, which interferes the normal life of the surrounding residents. So it’s important to develop rational reactive compensation plan. With the development of power electronics technology, the application of new reactive compensation devices becomes more and more wide. Static synchronous compensator (STATCOM) has attracted considerable attention due to superior performance of compensation and small footprint. We intensive study the reactive compensation of STATCOM in urban substations in this artical.Firstly, we analyze the problems of urban centers substation construction, operation and maintenance, including the quality of electric energy and environment issues. We calculate the reactive charging of cable in detail and propose the necessity of reactive power compensation. Then we point out the problems about reactive configuration existing in substation and introduce the structure and operating principle about two typical new reactive power compensation devices.The effect and operating principle of STATCOM in the reactive compensation is studied. We introduce the structure of device and propose a control strategy of it. We analyze the voltage stability, response time, suppression of voltage flicker and harmonic characteristic of device. We build STATCOM and SVC models in PSCAD/EMTDC and simulated analyze reactive compensation effect of two devices in a simple system. The STATCOM device is superior to SVC device in various performance.Besides, the important issue faced nowadays, that is the reactive power problem of the 220kV Daxinggong transformer substation was analyzed, and a technique reform plan was proposed using STATCOM as the reactive compensation. Also, each links in the generation of reactive power of transformer substations in center of cities was analyzes in detail, and a computing method to calculate the reactive compensated capacity was presented. Finally, we summarized the typical designing scheme of dynamic reactive power compensation in downtown substation, and analyzed the benefits of using STATCOM in reactive power compensation.