光伏微网系统孤岛检测技术研究

Islanding Detection in Photovoltaic Micro-grid System

随着智能电网的建设,微网系统以其提高电力系统的供电可靠性和一定的调峰作用将成为智能电网的重要组成部分。微网系统的孤岛检测是其中重要的研究方向之一。论文采取主动式与被动式孤岛检测算法相结合并在传统的电压正反馈式孤岛检测技术上进行改进,研究优化选取反馈系数的方法,设置合理反馈系数以便该孤岛检测算法能适应各种功率等级的输出要求,并提高逆变器输出效率和不同功率等级条件下孤岛检测效率。实验表明该方案适用不同负载功率等级,在负载功率较小时逆变器输出效率达到95%,谐波含量比传统方法低0.85%,大功率负载时能够及时检测出孤岛。

With the construction of smart grid, micro-grid system, which increases its power supply reliability of electric power system and has some peak adjustment effect, will become an important part of smart grid. The islanding detection of micro-grid is one of the impor- tant research directions. This paper takes the active islanding detection algorithm combined with passive islanding detection algorithm, im- proves on the traditional voltage positive feedback detection, studies ways to optimize the selection of feedback coefficient, sets reasonable feedback coefficient so that the islanding detection algorithm can adapt to various output requirements of different power levels, and increases the system output power and detection efficiency under different power levels. Experiments indicate that this proposal is adaptive to various load power levels, when the load power is small, the efficiency of the inverter output can reach 95 ~, harmonic content is 0. 85 % lower than traditional methods, as well as the timely detection of the islanding occurrence in the case of high load power level.