基于Bergeron等值线路的机电电磁混合仿真接口模型

An Interface Model of Electromechanical and Electromagnetic Hybrid Simulation Based on Equivalent Circuit of Bergeron Line

在进行机电电磁混合仿真时常选用戴维南/诺顿等值接口模型,但由于等值受控源在数据交互时接收到的受控量是对侧系统上一个仿真步长的解算结果,导致接口中存在不应有的交互延时,从而造成混合仿真精度低、收敛性差等问题。针对上述问题,基于Bergeron等值方法将较短的输电线路转变成由波阻抗、线路阻抗和历史电流源组成的"Bergeron等值线路"接口模型。其中,历史电流源与波过程的传输延时相关,对当前解算时刻是已知量,可以利用其"历史受控量"的特性抵消掉接口交互延时对混合仿真解算精度和收敛性的影响。同时,针对机电和电磁侧步长存在较大差异导致的解算误差,通过在电磁仿真中对机电侧数据进行插值,以提高混合仿真的精度。最后,通过相关算例仿真验证了所提算法的精度及其优势。

Thevenin or Norton equivalent interface model is commonly used in electromechanical and electromagnetic hybrid simulation. Whereas, the controlled variables received by equivalent controlled source is the calculation result of the previous simulation step on contralateral system during data interaction, resulting in an unnecessary interactive delay in the interface. As a result, the hybrid simulation has drawbacks of low accuracy, poor convergence and others. In this paper, short transmission line is transferred into the interface model based on the equivalent circuit of Bergeron line composed of wave impedance, line impedance and historical current source. In the interface model, the historical current source is related to the propagation delay of wave process, and is a known quantity at the moment of current calculation, so its feature of ‘historically controlled variables’ can be used to offset the effect of interface interaction delay on accuracy and convergence of hybrid simulation solutions. Meanwhile, the calculation error caused by the difference of step sizes between electromechanical and electromagnetic sides is analyzed. Further, the interpolation algorithm of electromechanical data is applied to improve accuracy of hybrid simulation on electromagnetic side. Finally, a practical case is given to verify accuracy and advantages of the algorithm.