特高压直流输电线路分段直流融冰方案

Segmented DC Ice-melting Solution of UHV DC Transmission Lines

针对融冰线路一般不是全线覆冰的情况,提出了在重冰区线路下方建设分段直流融冰站的分段直流融冰方案。融冰距离取100km,通过对特高压直流线路大截面导线融冰电流范围和融冰时间的计算,确定融冰电流为12 000A,所需融冰功率153MW。为满足融冰功率的需求,提出了分段直流融冰站所需交流电源的电压等级为220kV。最后设计了2套24脉动整流电路并联的分段直流融冰装置,并对装置的设备参数进行了设计选型。通过Matlab仿真软件对特高压直流线路的分段直流融冰进行仿真,结果表明设计的装置其融冰电流可达10 980A,且输出电压为24脉动,总谐波畸变率(THD)仅0.83%,验证了该方案的可行性。

Scince the lines needing to be ice-melt are normally not fully ice-covered,we propose a segmented DC ice-melting solution of constructing several segmented DC ice-melting stations under the heavy-iced lines.Setting an ice-melting distance of 100 km.we calculate the ice-melting current range and ice-melting time of large section conductors for ultra-high voltage DC（UHVDC） transmission lines： the ice-melting current is 12 000 A and the required ice-melting capacity is 153 MW.In order to meet the demands of ice-melting capacity,the AC power supply voltage level of the segmented DC ice-melting stations is proposed to be 220 kV.Finally a segmented DC ice-melting device with two parallel 24-pulsed rectifiers is designed,and its device parameters are calculated and designed.Simulation results of segmented DC ice-melting of UHV DC transmission lines in Matlab show that the ice-melting current can reach 10 980 A while the output waveform of the device is 24-pulse with a total harmonic distortion（THD） of 0.83%,which verifies the feasibility of the proposed method.