CAJ | 학술논문

从双馈风电场故障序阻抗特征的角度出发，利用解析法分析了影响风电场送出线保护正确选相的原因。推导了双馈风电场启动转子撬棒保护后的序阻抗表达式，指出此时正、负序阻抗是风电场等效转速和撬棒阻值的函数，说明对于双馈风电场，电源正、负序阻抗近似相等的假设难以成立，由此导致风电场侧保护处各序电流分配系数也产生很大差异。基于以上结论，分析了相间电流突变量选相和对称分量选相发生选相失败的原因。最后，基于 RTDS 建立了仿真模型，对理论分析做了进一步验证。
종쌍궤풍전장고장서조항특정적각도출발，이용해석법분석료영향풍전장송출선보호정학선상적원인。추도료쌍궤풍전장계동전자효봉보호후적서조항표체식，지출차시정、부서조항시풍전장등효전속화효봉조치적함수，설명대우쌍궤풍전장，전원정、부서조항근사상등적가설난이성립，유차도치풍전장측보호처각서전류분배계수야산생흔대차이。기우이상결론，분석료상간전류돌변량선상화대칭분량선상발생선상실패적원인。최후，기우 RTDS 건립료방진모형，대이론분석주료진일보험증。
In consideration of the influence of sequence impedance of doubly fed induction generator (DFIG),an analytical method is used to find out the factors affecting the correct action of the phase-selection elements in wind farms.The expressions for the sequence impedance considering the Crowbar protection are derived,which shows that the positive and negative sequence impedance of DFIG are functions of the equivalent rotational speed and crowbar resistance.It is then pointed out that the common hypothesis that the positive and negative sequence impedance of the power sources is nearly equivalent cannot be considered valid for the DFIG plants,which then causes great differences in the current distribution coefficients of the line protections.Based on the above analysis,this paper discusses in detail the reasons why the phase-selection principles based on variation and sequence components cannot be applied to DFIG plants.The simulation results using RTDS have further proved the theoretical analysis.