分布式发电接入电网继电保护研究

Research on the Relay Protection for Distributed Generation Accessing to Power Grid

常规电源与分布式电源的差异使得分布式电源接入电网时,传统继电保护受到很大影响。先从分布式电源的类型、分布式电源容量方面,介绍了对电流保护的影响,得出分布式电源容量越大、短路电流越大的结果。然后从分布式电源接入位置及测量电压电流特性方面,介绍了对距离保护的影响,得出分布式发电带来助增电流、频率偏差等是影响距离保护的主要因素。通过改变整定值、分区隔离、附加分量和逻辑等途径,改进电流距离保护方案。最后展望了自适应保护是保护发展的重要方向。

The traditional relay protection is greatly affected by the difference between conventional power supply and distributed power supply at the time that the distributed power is connected to the power grid. Firstly, from the types of distributed power supply and the capacity of distributed power, the influence on the current protection is introduced, it is concluded that the larger the distributed power capacity is, the higher the short - circuit current is. Then, the influence on the distance protection is introduced from the accessing location of the distributed power supply and the characteristics of measurement voltage and current, and the conclusion is that the assisted increasing current produced by distributed generation and the frequency deviation are the main factors affecting the distance protection. By the ways of changing the tuning value, zoning isolation,and additional component and logic,etc. ,the current and distance protection scheme is improved. Finally, the research prospect that adaptive protection is the important direction of protect development.