直流电弧加热炉谐波的小波降噪仿真分析

Wavelet Denoise Simulation on DC Arc Heating Furnace

摘要:

90 MW直流电弧的电流控制采用2台整流变压器控制,通过调节晶闸管桥触发角构成24 脉波整流电路.24脉波整流电路产生谐波以11,13,23和25次谐波为主，这些高频谐波对电弧加热炉的电流调节的有效性造成了很大的危害.采用多种小波阈值对90 MW直流电弧加热炉电系统谐波信号进行降噪，并从中选择了最优的降噪阈值，达到对信号的优化处理.仿真结果表明，该直流电弧系统谐波信号小波降噪的最优阈值为sqrt(2log(length(X)))阈值，降噪后可使信号中的谐波成分明显降低，保证了直流电弧系统的可靠运行.

Abstract:

90 MW DC arc furnace uses the current 2transformer rectifier bridge thyristor controlled by adjusting the angle trigger to compose 24 pulse wave rectifier circuit.The 24 pulse wave rectifier circuit generates harmonics mainly about 11,13,23 and 25 times harmonic,these highfrequency harmonics do great harm to arc furnace on the effectiveness of the current regulation.A variety of wavelet is employed in thresholding 90 MW DC arc furnace power system harmonic signal noise,and the optimal choice from the noise threshold optimize the signal processing correspondingly.The simulation results show that 90 MW DC arc furnace system harmonic signal wavelet denoises the optimal threshold for sqrt (2log (length (X))) threshold,and the harmonic components reduce obviously,as a result,the operation of the 90 MW DC arc furnace is ensured.