Wavelet Transform and Time Frequency Atoms Based Approach to Power Quality Monitoring

摘要（ec -0140636）将开发一种准确、高效的电能质量监测方法。功率干扰通常是具有幅度变化和频率偏差的非平稳信号。本文提出了一种用于电能质量监测的复杂时频原子（TFA），其中心频率和频率半径之间不存在耦合。基于TFA的小波变换方法相对于基于复小波函数的小波变换方法具有以下优点：(1)由于每个滤波通道的中心频率和频率半径可以单独灵活地设置或调整，从而实现了在频率平面上对一个基元和谐波指定的不同滤波通道的分离，即消除了彼此之间的干扰。提出了基于复小波函数和小波变换的“小波能量分布”概念，通过非均匀频率窗实现“频谱扫描”。此外，将使用TFA和WED创建新的电能质量指标。该方法将通过使用模拟功率干扰波形进行评估，然后在实验室和工业现场进行基于硬件实现的在线评估。基波分量和谐波分量的幅值和频率的准确估计对电力系统的控制和保护也至关重要。因此，该项目不仅将促进电能质量领域的研究和教学，而且将促进电力系统控制、保护和电力仪表/仪器的开发。

ABSTRACT (ECS-0140636)An accurate and efficient approach to power quality monitoring will be developed. A power disturbance is typically a non-stationary signal with magnitude variance and frequency deviation. The proposed work deals with constructing the complex Time Frequency Atom (TFA) for power quality monitoring, in which there is no coupling between the central frequency and frequency radius. The TFA based Wavelet Transform (WT) approach has the following advantages over that based on a complex Wavelet function: (1) Since the central frequency and frequency radius of each filtering channel can be set or tuned separately and flexibly, the separation of different filtering channels, which are designated for a fundamental component and harmonics, in the frequency plane can be achieved, i.e. eliminating the interference between each other. The concept of "Wavelet Energy Distribution"(WED) is proposed, which is based on a complex Wavelet function and WT, to fulfill the "spectrum scanning" by a non-uniform frequency window. Further, novel power quality indices will be created that use the TFA and WED. The approach will be evaluated by using simulated power disturbance waveforms, followed by an on-line evaluation in the laboratory and in industrial sites, based on hardware implementation. The accurate estimation of magnitudes and frequencies of fundamental as well as harmonic components is also essential to power system control and protection. Therefore, the project will promote research and teaching in not only the power quality field but also power system control, protection, and the development of power instruments/apparatus.