新能源多场站短路比影响因素分析

Influencing factors analysis of short circuit ratio for multiple renewable energy stations

新能源在电力系统中的接入占比不断增加,使得局部地区出现了新能源接入弱交流电网的场景,易引发新能源振荡失稳及过电压脱网风险。计及多个新能源场站间相互影响的新能源多场站短路比(multiple renewable energy stations short circuit ratio,MRSCR)是衡量新能源接入系统电压支撑强度的重要指标。首先,推导了MRSCR的计算公式,结合不同假设条件,给出不同解析表达式;其次,详细分析了影响新能源多场站短路比的因素,包括新能源场站发电功率、节点运行电压、加装调相机等,并对上述因素的影响效果进行理论推导;最后,为进一步验证上述因素对MRSCR的影响情况,依托电力系统分析综合程序(power system analysis synthesis program,PSASP),以宁夏某新能源场站为例进行了仿真分析。仿真结果表明新能源场站发电功率、加装调相机对MRSCR具有显著影响,上述结论对指导高比例新能源接入系统电网运行及新能源场站规划设计具有重要意义。

As the scale of new energy integration in the power system continues to expand, it appears in some local areas that new energy is connected to weak AC power network. That will easily result in overvoltage offgrid caused by instability due to oscillation. The multiple renewable energy stations short circuit ratio(MRSCR)influenced by new energy in multi-stations is an important index to measure the capacity of voltage support while integrating into new energy system. Firstly, the calculation formula of MRSCR was derived. Different analytical pattens were worked out based on varying assumptions. Then, a detailed analysis of the factors affecting MRSCR was provided, including power generation in new energy station, node operating voltage, and installation of synchronous phase modifier. Finally, to further test the influence of the above factors on MRSCR, an analysis of new energy station in Ningxia was presented as an example, which was based on power system analysis synthesis program(PSASP). The results show that power generation in new energy station and the installation of synchronous phase modifier have significant impacts on MRSCR. The conclusion will play a guiding role in operating integration of new energy into the power network at a high proportion and in planning the construction of new energy stations.