基于FFT与小波变换结合的嵌入式电能质量检测系统  

The Embedded System for Power Quality Detection Based on FFT and Wavelet Theory

作　　者：沈海滨[1] 郑寿森[1] 祁新梅[1] 

机构地区：[1]中山大学电力电子及控制技术研究所,广东珠海519082

出　　处：《中山大学学报（自然科学版）》2014年第4期40-44,共5页Acta Scientiarum Naturalium Universitatis Sunyatseni

基　　金：广东省自然科学基金资助项目(8451027501001493)

摘　　要：该文研究应用FFT在频域与小波变换在时域的优势,设计搭建了基_4 FFT与Daub4小波变换结合的嵌入式电能质量检测系统。该系统利用小波变换检测电压骤升、骤降等暂态问题,使用FFT分析稳态下电信号谐波。为验证系统的实际检测能力,分别对稳态、电压骤降、电压暂态干扰三种状况进行了实时监测测试和Matlab软件分析,结果表明:该嵌入式电能质量检测系统在稳态时,检测基波幅值的误差为0.3%,满足公用电网GB/T 14549—93对谐波测量仪器的A级标准;同时,在电压骤降、电压暂态干扰状态下也能准确检测到电信号的突变时间,实际系统检测和软件仿真结果误差在1.6 ms内,满足实时性要求。The advantages of FFT application in frequency domain and wavelet theory in time domain were studied , and an Embedded System for Power Quality Detection （ ESPQD ） based on radix-4 FFT and Wavelet Transform is developed .The ESPQD uses the wavelet theory to monitor the transient power qualityincluding voltage dip , voltage swell and so on .FFT is applied to analysis harmonics of electrical signals in steady-state.Three different states including steady-state, voltage dip and transient interference were tested with both the ESPQD hardware system and Matlab simulation for verification .The results show that the amplitude error of fundamental wave is within 0.3%, meeting the A level standard of the u-tility grid standards GB/T 14549-93 about harmonic measuring instruments .The system can also pre-cisely and quickly detect the abrupt changes of the electrical signals during voltage dip and transient in -terference .The time difference between ESPQD and simulation is within 1.6 ms and the system can be used in real time measurement .

关 键 词：FFT 小波变换 电能质量 

分 类 号：TM933.4[电气工程—电力电子与电力传动]