Research On Micro-grid System Grid-connected Point Control And Protect Unit

Since the reform and opening up, China’s economy has made a great progress. But with the economic development, demand for electricity is increasing.Conventional power generation systems excessively consume the energy, and the environment has a huge pollution. To address this serious situation, the provision of such as wind power, solar power and other new energy model has been more widely applied to the current electricity production. Micro-grid as a new technology with high efficiency, variability advantages can largely solve the energy shortage problem.Micro-grid operation mode can be simply divided into island operation and grid-connected operation. Currently the main way put micro-grid into a large grid system is direct grid-connected, which is micro-grid voltage and frequency coordination side meet certain criteria, and then closed the common connection point between the micro-grid and large grid, and ultimately to achieve grid-connected. Islanding operation is defined as when a large grid due to electrical failure or some natural factors and other conditions caused by power failure, the system is not able to quickly determine the micro-grid in the island state, and a number of distributed energy load can still form a small system operation, so it become a self-sufficient power system from the big power supply control system.This paper describes the main features of the device structure and micro-grid research, and other means to achieve this function to do a simple introduction. The grid-connected control, islanding detection and over current protection has done a detailed analysis in the paper, a more detailed exposition of the islanding detection classification. In this paper, the hardware design choice of high efficiency CPU chips and other auxiliary chip for communication between the various modules were also reasonable design, in order to better realize the device functions. Finally, the hardware implementation of this function for programming. This paper uses the software platform is MCF52295, it corresponds to the program development environment CodeWarrior. And unit researches conducted debugging.