基于短路比指标的新能源并网容量极限计算

Calculation of new energy grid-connected capacity limit based on short-circuit ratio index

针对新能源并网系统抗干扰能力弱且稳定性较差等问题,在短路比指标的基础上,提出了一种适用于新能源发电机组和交流电网之间的系统容量计算方法。通过推广电网系统的短路比指标,利用电力电子多馈入系统灵敏度计算方法,实现系统容量受到小干扰因素影响时变化情况的精准评估,并且获取系统在达到临界状态时的具体条件,从而实现新能源并网系统中容量极限的精确计算和分析。仿真结果表明,与经典容量极限计算方法相比,基于短路比指标的容量极限算法具有更高的稳定性及抗干扰能力。

In view of the weak anti-interference ability and poor stability of new energy grid-connected systems,based on the short-circuit ratio,a system capacity calculation method for the new energy generator units and the AC power grids was proposed.By promoting the short-circuit ratio index of the power grid systems and using the sensitivity calculation for method the power electronics multi-infeed systems,the system capacity could be accurately evaluated when affected by small interference factors,and the specific conditions of the systems reaching the critical state could be obtained,so the accurate calculations and analysis of the capacity limit for the new energy grid-connected system were achieved.The simulation results show that the capacity limit algorithm based on short-circuit ratio index has higher stability and anti-interference ability than the classical capacity limit algorithm.