电弧炉电气系统谐波分析的频域方法研究

文中对电弧炉电气系统谐波分析的频域方法进行了研究。首先对电弧电压波形进行了傅立叶分析，接着讨论了电弧炉系统谐波分析的思路。从替代定理和叠加原理出发，将三相对称及不对称电弧炉系统简化为单相系统进行求解。经过电路分析，导出了电弧炉系统主电路谐波、注入电网谐波、流过电容器谐波的解析计算公式。分析表明：电弧炉系统的主电路谐波的大小与系统的谐波阻抗、电弧电压波形和电弧炉的平均功率因数有关，电弧炉注入电网的谐波主要为低次谐波。当电弧炉电气系统在串联谐振点和并联谐振点附近时，均会出较大谐波电流，而串联谐振对系统的影响更大一些。

Research on Harmonic Analysis of Arc Furnace Electric System Based on Frequency Domain Method

Research on the harmonic analysis of arc furnace electric system based on frequency domain method is made. First, Fourier analysis is made for the arc voltage, and then the idea of harmonic analysis is discussed. In accordance with superposition theorem and substitution theorem, the symmetric three-phase and asymmetric three-phase arc furnace electric power system is reduced as a one phase system. With the circuit analysis, the analytic formulas such as harmonic current of arc furnace main circuit, harmonic of injecting electric network and harmonic of flowing into capacitance are derived. It is showed by analysis that the harmonic magnitude of arc furnace system relates to harmonic impedance of system and arc voltage, and mean power factor of arc furnace, the harmonics of injecting electric network from arc furnace are main low harmonics. The arc furnace electric system will make appearance of more harmonic current at the series resonant point and the parallel resonant and influence of series resonant is larger for the system.