考虑微网充电站影响的输电网风险评估方法

摘要

微网充电站接入配电网后,传统的辐射型配电网中将存在电源,这就造成在传统的输电网风险评估方法中配电网不能够再简单等效为一个无源负荷点.为了分析这种影响,提出了考虑微网充电站影响的输电网风险评估方法.首先介绍了风险评估基础理论,然后重点分析了微网充电站概率模型,包括分布式电源出力概率模型和电动汽车(Electric Vehicles, EV)充电负荷概率模型.应用考虑了配电网层面影响的期望负荷削减量代替绝对负荷削减量.最后应用测试系统验证了所提方法的有效性,包括微网充电站中分布式电源容量配置比例以及反送电比例对于输电网风险指标的影响.分析结果表明,微网充电站能够有效降低输电网风险水平.%With the micro-grid charging station connecting into distribution system, it exists power source in radiated distribution network which cannot be equivalent to a passive load point in traditional transmission system risk assessment of distribution network. A risk assessment method for transmission system considering micro-grid charging station is proposed to analyze this effect. First of all, this paper introduces theoretical basis of risk assessment, then emphatically analyzes probability model of micro-grid charging station, including output probabilistic model of distributed generation and charging load probabilistic model of Electric Vehicles (EV). The expected load curtailment influenced by distribution network is applied to replace absolute load curtailment. Finally, the effectiveness of the proposed method is verified by using a testing system, the influence on risk index of transmission network by the proportions of distributed generation capacity and reverse power transmission network in micro-grid charging station is analyzed. The analysis results show that micro-grid charging station connected into distribution network can effectively reduce risk level of transmission system.