基于LM法的换流站关键设备宽频建模方法研究

直流输电系统换流站存在多种产生或传输谐波的电气设备，建立适用于仿真研究的换流站宽频模型十分重要。传统建模方法较为复杂，且不适用于低阶等效模型。因此，基于元件物理模型和阻抗特性，利用列文伯格-马夸尔特算法求解宽频模型参数、拟合阻抗特性曲线，并简化了宽频模型。然后据此建立了晶闸管、平波电抗器和换流变压器等换流站关键设备的宽频模型，验证了该方法的正确性。最后，将元件宽频模型等效电路应用于仿真模型，仿真对比表明宽频模型相比于理想模型，5次谐波幅值减小约基波的1.7%~1.8%，并且简化宽频模型可以加快仿真速度。

Broadband Modeling of Key Equipment in Converter Station Based on Levenberg-Marquardt Algorithm

There are many kinds of electrical equipments generating or transmitting harmonic in the converter station of HVDC system. It is very important to establish broadband model for the converter station to carry out simulation study. Traditional modeling methods are complex and not suitable for low-order equivalent models. Firstly， based on the physical model of component and impedance characteristics， this paper uses Levenberg-Marquardt algorithm to solve the broadband model parameters， fits the impedance characteristic curve， and simplifies the broadband model. Then the broadband model of thyristor， flat-wave reactor and converter transformer is established to verify the correctness of the proposed method. Finally， the equivalent circuit of the broadband model is applied to the simulation model. The simulation comparison shows that the amplitude of the fifth harmonic of the broadband model decreases about 1.7%~1.8% of the fundamental wave compared with an ideal model， and the simplified broadband model can accelerate the simulation speed.