安全约束最优潮流的实用模型及故障态约束缩减方法

Practical Model of Security Constrained Optimal Power Flow and Reduction Methods for Contingency Constraints

针对大型电力系统安全约束最优潮流(SCOPF)问题具有的计算规模庞大、求解困难的特点,提出了基于潮流转移关系的SCOPF实用模型及故障态约束缩减方法。首先通过预想故障分析建立故障前后的有功潮流转移关系,将故障态支路有功潮流描述为基态支路有功潮流的函数,从而将故障态支路有功潮流约束描述为基态支路有功潮流的线性不等式约束;然后通过对并联线路或并列主变压器进行分组,利用组内支路的有功潮流分布关系减少需监视的支路规模;最后利用设备短时通流能力明显大于其长期通流能力的特征对故障态支路潮流约束进行过滤,以尽可能减小SCOPF问题的计算规模。IEEE 14节点测试系统和华东电网的仿真分析验证了所提模型及约束缩减方法的正确性和有效性。

Security constrained optimal power flow （SCOPF） for large scale power systems is a complex and difficult problem with its highly demanding computational requirements. A practical SCOPF model is presented based on power flow transfer relations and related constraint reduction methods are proposed. According to the power flow transfer relations established by contingency analysis, the active power flows on branches in post-contingency state can be described as linear functions of those in pre-contingency state. Therefore, the active power flow constraints of the branches in post-contingency state are described by the reformed linear inequality constraints of the active power flows of the branches in pre-contingency state. Furthermore, by grouping the parallel lines and parallel transformers, the number of monitored branches is reduced by using the distribution relations of active power flows in grouped branches. Finally, since the short-term capacity of power equipment is usually much greater than the long-term capacity, the power flow constraints of the branches in post-contingency state are accordingly screened to reduce the scale of SCOPF problem as much as possible. Simulations on the IEEE 14-bus test system and the East China power grid verify the correctness and effectiveness of the proposed SCOPF model and the constraint reduction methods.