适用于混合仿真的戴维南等值阻抗改进求取算法

由于基于机电暂态数据获得的机电侧系统戴维南等值阻抗参数难以体现接口发生故障后机电侧系统的电磁暂态特性,文中提出了一种基于电磁暂态短路仿真的机电-电磁暂态混合仿真机电侧戴维南等值阻抗改进求取算法。该算法是基于一种不受各次谐波影响的系统时间常数求取方法,通过全电磁暂态模型的接口位置设置2次不同接地电阻的三相短路故障,联立时间常数方程计算得到机电侧系统的等值阻抗信息。与传统的基于机电暂态模型通过单位电流注入法计算出的等值阻抗相比,文中方法计算出的等值阻抗能够更准确地体现接口发生接地故障后机电侧系统的电磁暂态特性,从而提升了机电-电磁暂态混合仿真故障期间和故障后的仿真精度。

Improved Thevenin Equivalent Impedance Calculating Method for Hybrid Simulation

As the Thevenin equivalent impedance parameter which is deviated form stability-type simulation data can hardly reflect the electromagnetic characteristics of the electromechanical-side system after fault, an improved calculating method of Thevenin equivalent impedance of electromechanical-side system for electromechanical-electromagentic hybrid transient simulation based on electromagnetic transient simulation model is proposed. The Thevenin equivalent impedance parameter is achieved through setting two three phase line to ground faults on the interface bus in the full-electromagnetic transient simulation model and solving the primary time constant equation group in which the primary time constant is based on a calculating method which is not affected by every harmonic component. Compared with the equivalent impedance calculated by the traditional method which calculates the impedance based on the stability-type simulation data and through unit current injection method, the equivalent impedance calculated with the method proposed in this paper can reflect the electromagnetic characteristics more accurately, thus improving the simulation accuracy of electromechanical-electromagnetic hybrid transient simulation during and after fault.