The Study Of Load Control Strategy Under Microgrid Island Operation Mode

With the rapid development of society, people rely on energy more and more, thusenergy issues are becoming grimmer, especially in the power sector. In our country, thepower production is mainly from thermal power recently, which accounts for theproportion to reach as high as80%, besides the thermal power generate electricity mainlyby burning coal and other non-renewable energy sources. Nowadays, with the wholecommunity gradually increases the requirements of power industry, so just simply relyingon the increasing electricity infrastructure reconstruction can not solve the problemseffectively. On the other hand, the environmental pollution caused by the burning of coalresources has also attracted more attention, therefore, it is necessary to find an efficient andreliable way to realize sustainable development. The distributed power which is poweredby clean energy and renewable energy adapts to the requirements of the power industry’sdevelopment. The micro-grid is a flexible and controllable small grid, which containdistributed power, load and storage devices. It can be used with large power grid paralleloperation, besides it can also escape from large power grid to form an island. Distributedgeneration technologies based on micro-grid system, which not only can provide a way forthe development of renewable energy, but also can effectively increase the generationcapacity of the power system, which has a great advantage relative to the traditional powergrid. The micro-grid system can also alleviate the energy crisis, reduce the environmentalpollution, improve grid reliability, provide better services for the power user, improvepower supply, improve the power consumption level of the whole society, but thereliability and economy of micro-grid operates are inseparable from the stable controlstrategy.The paper mainly studied the control strategy of the micro-grid, firstly it introducedthe concept of distributed power generation and micro-grid, and it also carried out adetailed analysis and research on wind power, solar power and fuel cells which arecommon distributed powers. In the paper we focused on the micro-grid island operationcontrol strategy, made a detailed description for the island. Based on fuzzy cluster analysis,studied load properties, which included load level, controllable characteristics andelectrical distance within island. When the distributed powers supply can not meet theloads demand in the island, island power systems that require removal or adjustment load,solving the priority load shedding load regulation order or priority issues of uncertainty, wecan get the control sequence of the island load. Finally, making the rural power grid for anexample, the paper described the link between rural power grid and micro-grid, made theisland state model to run for small micro-grid, according to the control strategy and beingachieved to meet the technical specifications to improve the rural power grid reliability andeconomy. By way of example, verified the correctness and validity of this method.