在系统侧和用户侧同时存在同频次间谐波源时,间谐波源识别中常用的有功功率法和阻抗法可能会给出错误的结论。提出了一种基于闪变电压归算的方法识别间谐波源,该方法通过测量基波等效阻抗、频率修正、相量运算得到各支路等效间谐波源,然后分别计算其作用于公共连接点的电压,同时考虑了不同频率对闪变影响的差异性,因此可以克服传统方法中同频次间谐波源相角差对测量结果的影响,并量化系统侧和用户侧的责任。在理论分析基础上,设计了一套数据采集装置并开发上位机软件实现所提算法。实验分析表明该装置工作可靠并验证了算法的有效性。
When both the supply side and user side have the inter-harmonic source of same frequency,the inter-harmonic source identification based on the active power flow method or impedance measurement method may give incorrect conclusion. An inter-harmonic source identification method based on the converted voltage flicker is proposed,which measures the fundamental impedance and carries out the frequency correction and phasor calculation to get the equivalent inter-harmonic sources of each branch. Because the voltages of common coupling point induced by the equivalent inter-harmonic sources are separately calculated with the consideration of flicker frequency difference,the influence of the phase angle difference among different inter-harmonic sources with same frequency on the measurement can be avoided and the responsibility of both system sides can be quantified. Based on the theoretical analysis,a data acquisition device is designed and the software algorithm of superordinate computer is developed. Experimental analysis shows the stability of the designed device and the effectiveness of the developed algorithm.