基于柔性电网的电能质量分析研究

Research of Power System Relay Protection

柔性电网采用电力电子技术,通过交直流间变换,实现电能远距离传输和高效利用。对于用户侧而言,直流微电网中因缺少一定的无功容量支撑正常的电压水平,导致电压跌落幅度较大,无法满足电能质量要求,容易引起电网第三道防线动作切除线路负荷,对地区电网而言带来安全稳定性问题。通过对柔性电网分析,建立柔性电网电压计算模型,对网络的低电压特性进行分析研究,采用末端补偿及直流电源点补偿相结合的方式解决电网电能质量问题。

Power electronic technology is used to achieve AC/DC conversion in the flexible grid, it can realize long distance power transmission and make use of power efficiently. In the DC micro-grid, there is no enough reactive power to support the voltage maintains a normal level, thus the voltage decreases in large amplitude, which would not meet the power quality demand, it＇s easily to cut supply line by the third line of the grid that caused by low level of voltage, meanwhile, it leads to safety and stability problem in the local grid. In this paper, flexible grid is analyzed to build the calculation model, using this model to analyze the low voltage character, Reactive power compensation which is used in the end of lines and the DC power point, with such method, the low voltage can be satisfied the demand of power quality.