基于风险价值的增量配电网效益风险评估

Benefit and Risk Assessment for Incremental Power Distribution Networks Based on Value at Risk

随着增量配电改革的不断深入,电网公司面临着愈加激烈的市场竞争,在增量配电投资业务上需要评估投资风险。为此,引入风险价值(value at risk,VaR)来量化电网公司在增量配电项目的投资风险。首先基于全生命周期理念构建增量配电网收益模型;然后考虑用电量、运维费率等不确定因素,采用蒙特卡洛法计算资本金净利润率(return on equity,ROE)的概率分布,在一定的置信水平下,通过Cornish-Fisher展开式求取ROE分布的近似分位数;最后根据ROE的近似分位数计算得到增量配电项目的风险价值。通过选取实际增量配电试点进行案例分析,结果表明VaR量化了投资风险,可辅助电网公司在投资增量配电项目时做出合理决策。

With constant deepening of incremental power distribution reform, power grid companies are facing increasing fierce market competition, which means requirement for assessment on investment risks in incremental power distribution networks. Therefore, this paper introduces value at risk (VaR) to quantify investment risks of power grid companies in incremental power distribution projects. It firstly establishes a profit model of the incremental power distribution network based on full life cycle, then considering uncertain factors such as electricity consumption and operation and maintenance costs, it uses Monte Carlo method to calculate probability distribution of return on equity (ROE). Meanwhile, at a certain confidence level, it works out the approximate quantile of ROE distribution by means of Cornish-Fisher expansion. Finally, according to the approximate quantile of ROE distribution, it works out VaR of the incremental power distribution network. By selecting an actual incremental power distribution network pilot for case study, it proves that VaR could quantify investment risks and assist power grid companies in making reasonable decisions on incremental power distribution projects.