计及风险控制策略的电力系统可用输电容量决策

针对风电装机容量较高的电力系统,在可用输电容量计算时需要合理计及风电机组出力不确定性可能导致的各种风险,文中在可用输电容量决策中引入了风险控制策略,在保证由于风电出力不确定性所引起的系统潮流越限风险不超过给定允许水平的同时,将由于风电机组实际出力不足而导致购电成本超过给定限值的风险控制在一定范围内。首先,将计及风险控制的可用输电容量决策描述为机会约束规划问题;然后,利用半不变量的Gram-Charlier级数展开理论计算相应可用输电容量决策方案下系统的安全风险和经济风险;最后,采用多目标差异进化算法求解所发展的优化模型,并以IEEE 118节点系统为例验证了所提出模型和方法的可行性与有效性。

Available Transfer Capability Decision-making with Risk-control Strategies

Aiming at the problem to calculate available transfer capability(ATC) of power system with high wind power capacity,reasonably account for the risks associated with wind generation,two risk-controlling strategies,including specifying the smallest acceptable probability for power flow limits not violated and the total generation purchasing cost limit not violated,are introduced into the ATC calculation for enhancing the ability of the obtained ATC scheme against security and economic risks.First,an optimal power flow based chance constrained programming model,with security and economic risk control strategies taken into account,is developed.Next,the security and economic risks associated with the power flow limit and generation cost limit violations respectively are evaluated by the combined use of cumulants and Gram-Charlier series.Finally,the multi-objective differential evolution algorithm is employed for solving the developed optimization model.The IEEE 118-bus system is served for demonstrating the essential features of the developed model and method.