CAJ | 학술논문

云广±800 kV特高压直流输电系统建成之后,将形成远距离和大容最交、直流输电并列运行的电网格局,特高压直流的控制方式对电网的稳定性有重要影响.为此在电磁暂态仿真软件EMTDC中对±800 kV云广直流双极运行下,整流侧分别采用定电流和定功率控制时,交流系统整流侧与逆变侧故障对直流系统的影响,直流控制系统与交流系统的响应过程进行了详细的计算分析,对两种控制方式下系统的动态特性进行了对比分析.结果表明,与整流侧采用定电流控制相比,定功率控制时,交流系统故障期间系统各电气量的变化较缓慢,故障清除后系统恢复过程中,直流电流的突增会导致短时换相失败,且故障后直流系统的恢复时间较长.
운엄±800 kV특고압직류수전계통건성지후,장형성원거리화대용최교、직류수전병렬운행적전망격국,특고압직류적공제방식대전망적은정성유중요영향.위차재전자잠태방진연건EMTDC중대±800 kV운엄직류쌍겁운행하,정류측분별채용정전류화정공솔공제시,교류계통정류측여역변측고장대직류계통적영향,직류공제계통여교류계통적향응과정진행료상세적계산분석,대량충공제방식하계통적동태특성진행료대비분석.결과표명,여정류측채용정전류공제상비,정공솔공제시,교류계통고장기간계통각전기량적변화교완만,고장청제후계통회복과정중,직류전류적돌증회도치단시환상실패,차고장후직류계통적회복시간교장.
when Yun-Guang±800 kV ultra high voltage direct current(UHVDC)project is completed,a parallel AC/DC power system with long distance and heavy capacity will come out.And the UHVDC control mode has important influence on the power system stability.Consequently,Yun-Guang ±800 kV UHVDC bipolar model was established in EMTDC.The effect of AC system faults on the UHVDC transmission system in both constant current and constant power control modes and the response of UHVDC control system were computed and analyzed,respectively.Moreover,the dynamic characteristic of the AC/DC system in two control strategies was comparatively annlyzed.The results show that,compared with the constant current mode,all the electrical variables change more slowly than in constant power mode during the power system fault.After the fault is cleared,a sudden increase of DC current may cause short time commutation failure.And the system needs more time to come back to normal operation.