【摘要】 该文提出了基于重采样理论和均值滤波的数字化谐波检测方法,该方法降低了数字低通滤波器的阶数和计算量。文中设计了一个数字谐波检测系统,该系统根据三相三线制电网的有功电流ip和无功电流iq只含3n(n为整数)次谐波这一特征设计数字均值低通滤波器;根据重采样理论在确保ip和iq的直流分量Ip和Iq的频谱不混叠的情况下可对ip和iq分别进行4倍重采样。通过该数字系统可实现电网谐波电流实时精确地提取。仿真试验表明,它既保留了数字滤波器的准确性,又克服了长期以来数字滤波器跟随性和实时性差的问题,具有较高的实用价值。更多还原

【Abstract】 A method for digital harmonic detecting based on resampling theory and the mean filtering is proposed, and a digital harmonic detecting system is designed. Because of containing only 3n harmonics (n is integer) in ip(iq), the filter can be designed as a mean filter to take the direct current Ip (Iq), and the ip(iq) before the low-pass filter can be resampled based on the resampling theory. Through this digital system the harmonic currents in power system can be detected timely and accurately. The Simulation of the system shows that this filter not only takes advantages of digital filters in accuracy, but also overcomes the bad performance of digital filters in dynamics, and can fellow the measured signal in real time.更多还原