机电-电磁暂态混合仿真复合非对称故障计算方法

为了提高机电-电磁暂态混合仿真对机电侧非对称故障的处理能力,进一步提升混合仿真对各类工况的适应性,本文提出了一种同时考虑机电侧非对称故障和电磁侧非对称故障的计算方法。首先提出了一种机电侧发生非对称故障后的机电侧故障仿真方法,该方法根据非对称故障的类型获取故障电路导纳矩阵,继而通过修改与故障节点相关的导纳元素,将故障电路导纳矩阵的叠加到原导纳矩阵中获得故障后的导纳矩阵,并通过求解网络方程获得故障后的网络解。然后根据线性电路叠加定理,提出了接口节点戴维南等值电势的计算方法。为减少电磁侧的建模量,采用接口正序等值导纳进行戴维南电势向诺顿等值电流的转化。最后结合含有一回直流线路的IEEE39节点系统的基于PSCAD+C架构的机电-电磁暂态混合仿真平台,验证了所提方法的精度和有效性。

Calculation Method of Complex Asymmetrical Fault in Electromechanical and Electromagnetic Transient Hybrid Simulation

To improve the processing ability of asymmetrical eletromechanical side fault as well as the flexibility of electromechanical and electromagnetic transient hybrid simulation,a calculation method of complex asymmetrical fault in the electromechanical and electromagnetic side at the same time is proposed.This method obtains the fault circuit admittance matrix according to the type of asymmetric fault.By modifying the admittance element associated with the faulty node,the fault circuit admittance matrix is superimposed on the normal admittance matrix to obtain the admittance matrix after fault.The network solution is finally achieved by solving the network equation after fault.Based on the linear circuit superposition theorem,the Thevenin equivalent voltage of the interface node is calculated.To reduce the modeling scale of the electromagnetic side,positive sequence equivalent conductance of the interface is used for the conversion of the Thevenin equivalent voltage into Norton equivalent current.At last,through the electromechanical and electromagnetic transient hybrid simulation platform of a IEEE 39 system containing a HVDC line based on PSCAD+C frame,the simulation accuracy and effectiveness of the method is validated.