This study investigated the feasibility of distance protection in extra-high voltage(EHV) networks. In long-distance transmission lines, the distributed parameter characteristic of the EHV network is obvious. When a f...This study investigated the feasibility of distance protection in extra-high voltage(EHV) networks. In long-distance transmission lines, the distributed parameter characteristic of the EHV network is obvious. When a fault occurs far away from the measurement site, the measured impedance might not be directly proportional to the fault distance, and the protection domain of distance protection will be decreased. The detailed theory inferred and proven in this paper reveals that this phenomenon is widespread in EHV transmission lines. The results indicate that the protection domain error is greatly reduced by the application of the shunt reactor. Overall, simulation results show that the proposed method is effective for impedance relay, considering different characteristics, different lengths of lines, and compensation degrees.展开更多
为了研究长距离交流输电线路上并联电抗器布置对功率传输的影响,基于长距离超、特高压输电线路分布参数等效电路及二端口模型,分析了传输线路的最大传输功率及最大传输效率,推导了串补条件下两种并联电抗器布置方案的级联传输矩阵。采用...为了研究长距离交流输电线路上并联电抗器布置对功率传输的影响,基于长距离超、特高压输电线路分布参数等效电路及二端口模型,分析了传输线路的最大传输功率及最大传输效率,推导了串补条件下两种并联电抗器布置方案的级联传输矩阵。采用500 k V、1 100 k V线路典型参数,针对并联电抗器布置对最大传输功率与最大传输效率的影响进行数值模拟分析。研究结果表明并联电抗器位置在发送端与中点串补电容之间或者接收端与中点串补电容之间变化时,最大传输功率与最大传输效率均随其位置变化而发生变化。同时,并联电抗器补偿度也会影响功率传输,随着并联电抗器补偿度的增加最大传输功率及最大传输效率均会降低。展开更多
文摘This study investigated the feasibility of distance protection in extra-high voltage(EHV) networks. In long-distance transmission lines, the distributed parameter characteristic of the EHV network is obvious. When a fault occurs far away from the measurement site, the measured impedance might not be directly proportional to the fault distance, and the protection domain of distance protection will be decreased. The detailed theory inferred and proven in this paper reveals that this phenomenon is widespread in EHV transmission lines. The results indicate that the protection domain error is greatly reduced by the application of the shunt reactor. Overall, simulation results show that the proposed method is effective for impedance relay, considering different characteristics, different lengths of lines, and compensation degrees.
文摘为了研究长距离交流输电线路上并联电抗器布置对功率传输的影响,基于长距离超、特高压输电线路分布参数等效电路及二端口模型,分析了传输线路的最大传输功率及最大传输效率,推导了串补条件下两种并联电抗器布置方案的级联传输矩阵。采用500 k V、1 100 k V线路典型参数,针对并联电抗器布置对最大传输功率与最大传输效率的影响进行数值模拟分析。研究结果表明并联电抗器位置在发送端与中点串补电容之间或者接收端与中点串补电容之间变化时,最大传输功率与最大传输效率均随其位置变化而发生变化。同时,并联电抗器补偿度也会影响功率传输,随着并联电抗器补偿度的增加最大传输功率及最大传输效率均会降低。
