地区电力系统供电能力评估

Supply capability assessment of regional power systems

随着电力系统规模不断增大、运行特性趋于复杂及用电负荷逐步增长,电力系统供电能力评估研究逐步由较大的省级电力系统延伸到相对较小的地区电力系统。地区电力系统供电能力能够反映该系统的可靠性、供电薄弱环节和与其它地区电力系统间的互联强度,可以在相当程度上据此来判断电力系统结构的优劣。传统的地区电力系统供电能力评估方法在计算时有可能遗漏一些重要的风险状态,如此得到的计算结果可能会有较大的误差。在此背景下,将地区电力系统供电能力计算描述为非线性有约束优化问题。之后,引入了基于支路开断分布因子的N-1预想事故分析方法,并采用差异进化算法来求取地区电力系统最大供电能力。最后,采用广东电力系统的两个实际算例来说明所提出的模型和方法的可行性与有效性。

With the continuous expansion of power systems,more complicated operating characteristics and substantial growth of the total load,the assessment of power system supply capability is needed not only in large provincial power systems,but also small regional ones.The supply capability of a regional power system can reflect the reliability/security and weaknesses of the concerned power system,as well as the interconnection strength between relevant regional power systems.Accordingly,the reasonableness of the network structure can be evaluated.The traditional supply capability assessment method for regional power systems do not properly account for some important risk factors,therefore the assessment results obtained are not accurate.Given this background,a new method is presented to assess the supply capability of a regional power system,and a nonlinear constrained optimization model is formulated.Then,the N-1 contingency analysis method based on the branch outage distribution factor is applied to simplify the computational complexity of the optimization problem,and the well-established differential evolution algorithm is next employed to search the optimal solution.Finally,two actual examples from Guangdong power system are employed to demonstrate the feasibility and effectiveness of the proposed model and method.