## 2 Simulation Model of CMIs with the CC Method  
### Configuration of the Proposed Model  
Figure 2 presents the layout of the suggested simulation model for single-phase CMIs. This model employs the permeance-capacitance analogy [26; 27; 28] and represents the single-phase CMI by segmenting it into two parts: magnetic and electric circuits [25].  
In order to reproduce the physical structure of magnetic components in circuit simulation, it is necessary to separate the electric circuit part from the magnetic circuit part. The model proposed in this article applies the permeance-capacitance analogy. The reluctance-resistance analogy is the well-known method for modeling magnetic components by separating the electrical and magnetic circuit parts [28]. The models obtained by both methods are mathematically equivalent. However, in the reluctance-resistance analogy-based model, the frequency characteristic of magnetic reluctance is simu  
Figure 2: Configuration of the proposed simulation model for single-phase common-mode inductors.  
of electrical resistance and inductance. Electric resistance, an energy storage component, is introduced in the circuit simulator to simulate magnetic reluctance, and inductance is introduced to simulate high-frequency losses. As a result, confusion may be caused when building the model.  
On the other hand, the permeance-capacitance analogy simulates magnetic permeance with capacitance and high-frequency losses by introducing resistance. In other words, the permeance-capacitance analogy-based model resolves the confusion caused by the reluctance-resistance analogy. Thus, this article employs the permeance-capacitance analogy for modeling common-mode inductors.  
The complex permeance \(P_{\mathrm{c}}\) of the magnetic core is implemented in the magnetic circuit part of the model, and the winding resistance \(R_{\mathrm{w}}\) and the parallel stray capacitance \(C_{\mathrm{p}}\) are implemented in the electric circuit part. Coupling between the magnetic and electric circuit parts is realized using a gyrator, an impedance inverting component. The gain \(G\) of the gyrator corresponds to the turn number and is set to half of the turn number (\(G=N/2\)). Furthermore, cancellation capacitors \(C_{\mathrm{can}}\) are connected between the connection point of two gyrators (the center tap of the winding) and the ground to simulate the CC method.  
All parameters of the proposed model for CMIs can be determined during their design phase. It is important to note that this model does not account for the leakage inductance of windings and interwinding capacitance, as the article concentrates on the small-signal characteristics of CMIs in CM. Winding resistance notably rises in the high-frequency range due to skin effects and other reasons. Nevertheless, the equivalent core loss resistance, resulting from the imaginary component of complex permeability, often far exceeds the winding AC resistance for the small-signal characteristics of CMIs at these high frequencies. Consequently, the model disregards winding AC resistance and includes only the winding DC resistance. An analysis comparing the equivalent core loss resistance with the winding AC resistance is provided in Appendix A.