基于可靠性量化的微电网变时间尺度协调调度策略

Coordinated Scheduling Strategy of Variable Time-scales for Microgrid Based on Reliability Quantification

随着光伏发电(Photovoltaic Power,PV)接入微电网渗透率的增加,其出力的波动性和不可控性导致常规机组的调节压力不断增大,在保证系统供电可靠性前提下如何实现微电网的经济调度已成为研究的热点。将系统供电可靠性分为安全性和充裕性两个指标分别进行量化,并将其作为改变日内调度时间尺度的约束判据,提出一种变时间尺度的协调调度模型:当预测PV发电量波动较小时,增大调度时间尺度以节约调度计算资源;而当预测PV发电量波动较大时,通过减小调度时间尺度提高预测的精度以保证系统可靠性要求。模型中,在日前通过短期预测制定机组运行和备用容量计划;在日内利用模糊函数计算PV预测误差隶属度,与不同可靠性量化的约束判据进行比较,动态决定下一调度时间尺度。算例中分析了不同权重系数下安全性与运行费用的关系,验证了模型的正确性和求解方法的有效性。

Since the regulating pressure of the conventional units caused by the fluctuation and uncontrollability of PV output constantly rises with the increase of permeability of the photovoltaic power（PV） connected with microgrid,how to realize the economic schedule becomes a hot research topic in the premise of ensuring the reliability of power supply.In this paper,the reliability is divided into security and adequacy which are quantified respectively and considered as a constraint basis to change the dispatch time scales in intra-day schedule.Then a coordinated scheduling model of variable time-scale is proposed.The model aims to increase the time scale to reduce the computing resources when the PV power output fluctuation is relatively small and reduce the time scale to ensure the reliability of micro-gird when the PV power output fluctuation is relatively large.Firstly,make plans for operation and reserve capacity of units by day-ahead short-term forecasting.Secondly,the degree of predictive error membership of PV calculated by ambiguity function in intra-day scale is compared with the quantitative constraint criterion of different reliability,and the difference is used to decide the next scheduling time scale.Finally,the paper analyzes the relationship between operation cost and reliability under the circumstances of different weight coefficients and verifies the correctness of the model and the validity of the method in the presented example.