Multi-time Scale Voltage Optimization Strategy of Distribution Network Considering Time Series Fluctuation Characteristics of Source and Load

With the integration of large-scale renewable energy sources into the power grid, its volatility and uncertainty bring great challenges to the operation of the power distribution network. This paper fully considers the time series characteristics of wind power, photovoltaic and electricity load. The output probability model of wind power and photovoltaic is constructed, and then typical scenarios are generated by synchronous back elimination method. The improvement of voltage deviation and fluctuation of distribution network is set as the optimization goal, and a multi-time scale voltage optimization strategy of distribution network is proposed. The strategy combines traditional reactive voltage regulation equipment with converters of distributed photovoltaic and wind power. In the day-ahead scale, capacitor banks and on-load tap changing transformers are used as the basic reactive power control equipment. The day-ahead scheduling plan is formulated to determine the hourly action plan of the slow-motion equipment in the next day. On the intraday scale, the regulation capacity of converters of photovoltaic and wind power is considered, and the voltage optimization is carried out on the minute level. The coordination of slow-motion equipment and real time power regulation of distributed generators can achieve the goal of voltage operation in the safe range of distribution network. The strategy is verified by IEEE 33-node system, and the results verify the effectiveness of the optimization method.