基于峰值波动的间谐波–闪变曲线制定

Establishment of Interharmonics-Flicker Curve Based on Peak Fluctuations

间谐波源也是引起电压闪变效应的闪变源,由此产生的电压闪变效应已逐步占据主导地位,需要制定合理的间谐波限制标准来抑制闪变的发生。国际上广泛认可的IEC闪变仪是基于电压调幅波模型,其并不适用于计算和评估由间谐波造成的电压波动和闪变问题。分析了IEC闪变仪在计算间谐波闪变时引起误差的原因,并提出采用同步解调取代平方解调,从而扩展带通滤波器的频带范围。在具体应用中,还讨论了载波信号的获取以及Butterworth低通滤波器阶数的选取问题,并在Matlab/Simulink中建立了新的基于同步解调的闪变仪模型。仿真结果表明,该闪变仪能够准确计算间谐波引起的电压波动和闪变,从而能够根据计算结果制定正确的基于峰值波动的间谐波–闪变曲线。

Recent researches show that the devices that produce the interharmonics are also the major sources of light flicker, and this kind of light flicker plays a dominant role gradually, so it is necessary to establish a rational restrictive standard of interharmonics to suppress the occurrence of light flicker. The wide recognized IEC flickermeter is based on the model of amplitude modulated wave of voltage, so it is not suitable to be used to calculate and evaluate the voltage fluctuation and light flicker due to interharmonics. The reasons causing the error during the calculation of interharmonics-caused light flicker by IEC flickermeter are analyzed, and it is proposed to replace the square demodulation by synchronous demodulation to expand frequency band range of band-pass filter. In actual application, the acquisition of carrier signals and the selection of the orders of Butterworth low-pass filter are discussed, and a new flickermeter model based on synchronous demodulation is built in Matlab/Simulink platform. Simulation results show that the synchronous demodulation-based flickermeter can accurately calculate both voltage fluctuation and light flicker caused by interharmonics, and correct interharmonics-peak fluctuation curve based on peak fluctuation can be established according to the calculation results.