基于几何分布的微电网孤岛运行可靠性快速概率评估

微电网内间歇性分布式电源和负荷的波动性使孤岛运行可靠性评估变得复杂。而避免负荷频繁投切的实际短时孤岛切负荷策略增强了负荷状态的时序关联性,该策略下序贯蒙特卡洛仿真计算量大。针对上述问题,文中基于几何分布模型和概率计算,提出了快速准确计算微电网负荷点停电时间概率分布的解析公式,可综合计算负荷点和系统可靠性指标。以改造的配电系统为例,通过评估微电网孤岛运行可靠性将所提方法与蒙特卡洛评估方法进行了对比分析,论证了所提方法的快速性和有效性;对源荷功率波动性和切负荷策略对微电网孤岛运行可靠性的影响进行分析,进一步验证了所提计算模型的合理性。

Geometric Distribution Based Fast Probabilistic Evaluation of Islanded Operation Reliability of Microgrid

The fluctuation of intermittent distributed generator and load complicates the evaluation of island operation reliability of microgrid. The temporal correlation between load states is strengthened by the adoption of a practical short-term load shedding strategy, which avoids frequently shedding and recovering load in the islanded mode. Based on this strategy, the computation burden of squential Monte Carlo simulation is heavy. Based on geometric distribution and probability calculation, this paper proposes a group of analytic formulas to quickly and accurately calculate the probability distribution of power outage time at microgrid load points. Then the load points and microgrid reliability indices can be calculated. Taking the reconstructed power distribution system as an example, the proposed method is compared with the Monte Carlo evaluation method by evaluating the island operation reliability in the microgrid, which verifies the rapidity and effectiveness of the proposed method. The effect of source-load fluctuation and load shedding strategy on the islanded operation reliability in the microgrid is analyzed, which further validates the rationality of the proposed model.