直流潮流与交流潮流的对比分析

Comparative Analysis on DC Power Flow and AC Power Flow

直流潮流因其具有线性表达和快速性而被广泛用于电力系统日前发电计划安全校核、电力市场阻塞管理、安全约束机组组合以及经济调度等场合。但是与交流潮流相比,其结果的误差及其与网络结构、运行状态的关系尚未得到深入分析。对IEEE多个测试系统和福建电网算例做了大量数值仿真,给出了误差的量化指标,并对误差与电压标准差、网络元件电抗电阻比及负荷状态等因素之间的关系进行了详细分析。研究表明对于电抗电阻比大于4且电压标准差值小于0.02的网络,采用直流潮流误差较小。

Because of its linearity and rapidity,DC power flow is widely applied in security assessment of day-ahead generation scheduling,congestion management of electricity market,security constraints of unit commitment and economical dispatching.However,comparing with AC power flow,the error of calculation based on DC power flow and the relations among the error,network structure and operation conditions are not yet analyzed in depth.Numerical simulations for four IEEE test systems and Fujian power system were performed and quantitative indices of the error were given,and detailed analysis on the relations among the error and such factors as voltage standard deviation,reactance to resistance ratios of transmission lines and load condition was carried out.Research results showed that for the power network with reactance to resistance ratio of network components greater than 4 and the voltage standard deviation less than 0.02 the error of calculation based on DC power flow was smaller.