复杂电网环境下时变谐波在线检测新方法及应用研究

In the complex power grid environment, the problem of harmonics is becoming more and more serious. Meanwhile, the randomness and uncertainty of harmonics are becoming more and more prominent. Fast and accurate on-line detection of time-varying harmonics is the primary premise for harmonic energy measurement, harmonic responsibility division, harmonic compensation and suppression. This project proposes a new on-line detection method of time-varying harmonics in the complex power grid environment. The major studies are as follows: ① Optimized window based on prolate spheroidal wave functions, which has the maximum energy aggregation, is constructed to replace the Gaussian window using in S transform. The generalized S transform is established as the results of optimized window with prolate spheroidal wave functions. ② By means of variable sampling rate and only calculating characteristic frequency points, the simplified generalized S transform based on optimized window with prolate spheroidal wave functions is built. And the time-varying harmonic parameters and dynamic information of power grid are accurately obtained by the time-frequency matrix of the proposed method. ③ An experimental platform for time-varying harmonic detection is built to verify the correctness and effectiveness of the algorithm. The key technologies and methods of this project can be widely used in the fields of other complex signal time-frequency analysis, which have high academic value and expectable application prospects.

复杂电网环境下，电网谐波问题日趋严重，谐波随机性和不确定性等时变特征日益凸显。实现时变谐波参数快速准确在线检测是谐波电能计量、谐波责任划分、谐波补偿与抑制的首要前提。本项目提出一种复杂电网环境下时变谐波在线检测新方法，研究包括：①采用具有最佳能量聚集度的椭圆球面波函数来替代S变换中的高斯窗函数，并以此构建基于椭圆球面波优化窗函数的广义S变换算法；②通过变采样率、仅计算特征频率点等方式建立基于椭圆球面波优化窗函数广义S变换简化算法，由变换算法的结果时频矩阵获取时变谐波参数和电网动态信息；③搭建基于嵌入式系统的时变谐波在线检测平台验证所提算法的正确性和有效性。本项目研究的理论方法和检测技术可广泛用于其他复杂信号时频分析领域，具有较高的学术价值和可预期的应用前景。

复杂电网环境下，电网谐波问题日趋严重，谐波随机性和不确定性等时变特征日益凸显。实现时变谐波参数快速准确在线检测是谐波电能计量、谐波责任划分、谐波补偿与抑制的首要前提。本项目提出了一种复杂电网环境下时变谐波快速、准确在线检测新方法，创建了主旁瓣性能优良、能量聚集度高、自适应能力强的新型椭圆球面波优化窗函数，并以此构建可基于椭圆球面波优化窗函数的广义S变换算法；通过时变谐波特征频率点与无关频率点的自动识别机制建立基于椭圆球面波优化窗函数广义S变换的简化算法，确保时变谐波参数在线检测的实时性；建立了基于椭圆球面波优化窗函数广义S变换的电网时变谐波特征提取新方法，可由变换算法的结果时频矩阵获取时变谐波参数和电网动态信息；设计与研制了基于ADC+DSP+ARM构架的电网时变谐波在线监测实验平台，对理论算法进行了嵌入式系统实现，测试结果验证了算法在时变谐波在线检测时的正确性和有效性。本项目研究的理论方法和检测技术可广泛用于其他复杂信号时频分析领域，具有较高的学术价值和可预期的应用前景。