含HVDC的电力系统次同步振荡参数稳定域的可视化分析

采用特征值分析法研究交直流电力系统中HVDC换流器控制对次同步振荡(SSO)模态阻尼的影响。利用MATLAB的数值计算和数据可视化能力，计算并在三维空间绘制了SSO模态阻尼相对于整流器控制参数平面的轨迹曲面，并提出一种可视化描述SSO参数稳定域的巧妙方法。发现各SSO模态都有一条最佳的模态阻尼脊线，阻尼不是分别随整流控制器增益和时间常数单调变化的。因此，减小时间常数和提高增益可以从参数不稳定域到达参数稳定域或者远离参数不稳定域，有利于提高鲁棒稳定性，但并不总是有利于改善SSO模态阻尼。

VISUALIZATION AND ANALYSIS OF THE PARAMETRIC STABILITY REGION OF SUBSYNCHRONOUS OSCILLATIONS IN AC/DC POWER SYSTEM WITH HVDC LINK

The influence of HVDC converter controls on the mode damping of sub-synchronous oscillations (SSO) in a AC/DC power system is investigated in this paper by using eigenvalue analytical method. Taking the advantage of the numerical calculation and data visualization functions in MATLAB, the curved surface of SSO mode damping to parametric plane of the rectifier control is calculated and drawn in three-dimensional space. Furthermore, an approach is proposed to visualize the parametric stability region of SSO. For every SSO mode, an optimal damping ridgeline is discovered and damping variation with gain and time constant of the rectifier control is not absolutely monotonous. Decrease of time constant and increa.se of gain can make SSO modes depart from the parametric instability region to the parametric stability region or far from the former. The trend is beneficial to robust stability, however, not always beneficial to mode damping.