Optimization of Ideal Transformer Interface Algorithm Based on Low-pass Filter

Numerical-model hybrid simulation techniques are increasingly being applied to a variety of fields in power systems and power electronics. The interface of the hybrid simulation model is the key in the research of the hybrid simulation technology. The ideal transformer interface algorithm is the most widely used, and the current ideal transformer interface algorithm usually incorporates a low- pass filter in the physical side current return circuit, but the existing research only considers purely resistive or purely inductive networks, and for resistive-inductive networks, as well as nonlinear networks, the cutoff frequency of the low-pass filter is mostly selected by empirical values, and there is no reasonable theoretical guidance. In this paper, the cutoff frequency selection range of low-pass filter in the improved ideal transformer method is derived, and the low-pass filter cutoff frequency selection method is proposed to improve the interface stability by selecting the appropriate low-pass filter cutoff frequency. Verification is performed by simulation.