Research On The Control Strategy Of Parallel Inverters In Micto-grids

Environmental protection and energy crisis has become the problem the world need to face, while the country’s rapid development is inseparable from the support of a strong grid, therefore, to build more advanced smart grid system has become the world’s research focus. Smart Grid will have a strong compatibility for distributed generation. In other words, with the rise of the smart grid, there will be more and more distributed generation join in the traditional power system for more users. Thus, the research of access technology of distributed generation is necessary. A sound approach is to construct the Micro-grid system. A typical Micro-grids always contain multiple parallelled micro-sources, most of which need the converters to transport power. Therefore, the control technology of parallel inverters is studied in this article.In this article, the control methods of parallel inverters in the micro-grids working in the island state is studied in detail. The first part is focused on the control of a single inverter module, including double loop control and conventional sv-pwm. After that, from a certain point of circulation generation, several mainstream parallel control methods are analyzed, comparing their advantages and disadvantages. Based on the first part, a new parallel control method is proposed. It applies improvements on the basis of traditional strategy to improve the redundancy of the system. Moreover, the parallel system designed in this article use the improved svpwm to suppress the harmonic. Simulation model is established in Matlab/simulink. Simulation is carried out when arbitrary module is connected or disconnected suddenly, or when the load changes suddenly. The results show that the control strategy proposed in this paper is effective, and it has some practical significance for the future development of parallel control technology.