CAJ | 학술논문

针对交直流互联输电系统的谐波不稳定问题，推导出判断直流系统是否发生铁芯饱和谐波不稳定的工程判据。该判据从直流输电谐波不稳定机理出发，计及直流偏磁铁芯饱和的影响，利用换流变直流偏磁产生的正序二次谐波幅度高于其他各次谐波的特点，整体考虑二次谐波通过换流器在交流系统和直流系统之间来回传递的全过程。算例分析建立了电磁暂态模型，通过PSCAD/EMTDC进行仿真，所得电磁暂态故障仿真的结果与基于新判据的频率扫描结果一致，验证了工程判据的正确性与适用性。
침대교직류호련수전계통적해파불은정문제，추도출판단직류계통시부발생철심포화해파불은정적공정판거。해판거종직류수전해파불은정궤리출발，계급직류편자철심포화적영향，이용환류변직류편자산생적정서이차해파폭도고우기타각차해파적특점，정체고필이차해파통과환류기재교류계통화직류계통지간래회전체적전과정。산례분석건립료전자잠태모형，통과PSCAD/EMTDC진행방진，소득전자잠태고장방진적결과여기우신판거적빈솔소묘결과일치，험증료공정판거적정학성여괄용성。
For the harmonic instability problem in AC-DC interconnected transmission system, this paper deduces the criterion to determine whether the DC system occurs core saturation harmonic instability. From HVDC harmonic instability mechanism and considering the DC bias magnetic core saturation effects, the criterion makes use of the characteristic that positive sequence second harmonic amplitude is higher than the other harmonic generated in DC magnetic bias of converter transformer, takes into account the whole process that the second harmonic transfers between AC and DC systems back and forth through inverter overall. In the case analysis, electromagnetic transient model is established and simulated by PSCAD/EMTDC, the result of electromagnetic transient fault simulation is consistent with the result of frequency scanning method based on the new criterion, so the correctness and applicability of engineering criteria is verified.