## 1 Introduction  
Lately, power semiconductor devices made from silicon carbide (SiC) have entered the market and are being utilized in numerous applications [1; 2; 3; 4]. These SiC-based power devices can complete switching operations ten times faster than their traditional silicon-based counterparts. As a result, by enhancing the switching frequency of power converters, there is the potential to minimize the size of passive components. Conversely, the significant dv/dt and di/dt associated with SiC devices contribute to a rise in high-frequency electromagnetic interference (EMI) in power converters [5; 6; 7; 4]. Consequently, implementing EMI filters is essential to achieve substantial noise reduction across a broad frequency range. Common-mode inductors (CMIs) combined with Y-connected capacitors form common-mode (CM) EMI filters [8; 9; 10]. For safety, the capacitances of Y-connected capacitors are restricted to a few nonfarads, necessitating CMIs with substantial CM inductance. Consequently, CMIs in power converters often have a larger size, weight, and cost. Typically, nanocrystalline or manganese-zinc (MnZn) ferrites are used as core materials in CMIs [11]. Nanocrystalline materials, with their high relative permeability of around 100,000 and saturation flux density near 1.2 T, greatly aid in downsizing common-mode inductors. Hence, their usage in common-mode inductors' magnetic cores is growing. Meanwhile, MnZn ferrites, with a relative permeability up to 10,000 and a saturation flux density between 0.3-0.5 T, offer benefits such as broad bandwidth, affordability, and versatile shaping, leading to their prevalent use in commercial common-mode inductors. The high relative permeability of these materials allows for fewer winding turns to achieve the desired CM inductance. However, independent of winding precision, CMIs experience self-resonance due to winding stray capacitance [12; 13; 14; 15; 16; 17], acting as capacitive impedances beyond the self-resonant frequency and weakening their high-frequency emission attenuation. Therefore, extra filter components are often needed to ensure sufficient CM noise attenuation across a wide frequency range, enlarging the EMI filter. The capacitance cancellation (CC) method has been introduced to enhance inductors' high-frequency attenuation [18]. As depicted in Figure 1, this method involves adding a center tap to an inductor \(L\) and a cancellation capacitor \(C_{\text{can}}\) between this center tap and a reference potential. Theoretically, \(C_{\text{can}}\) neutralizes the effect of stray capacitance \(C_{\text{p}}\) on the inductor's frequency characteristic, making the inductor with the CC method act like an ideal inductor. [PERSON] et al. applied CC to a single-phase CMI and experimentally showed that CC could boost CM emission attenuation by up to 20 dB at frequencies above 10 MHz [18]. [PERSON] et al. used the CC technique on three-phase CMIs [19]. However, previous studies identified stray capacitances from the measured attenuation characteristics and impedances of manufactured CMIs and determined the capacitance of cancellation capacitors accordingly. To date, to the authors' knowledge, there is a lack of circuit simulation models that can accurately simulate CMIs' attenuation characteristics with CC applied, making it challenging to assess these characteristics during the EMI filter design phase. In the previous work [20], an estimating method for winding stray capacitance of single-phase toroidal inductors that considers the insulation between the winding and the magnetic core has been proposed. It has been demonstrated that the proposed method can estimate winding stray capacitance with practically acceptable accuracy. Generally, single-phase toroidal inductors are fabricated by uniformly winding an entire toroidal core. On the other hand, CMIs are usually fabricated with multiple windings, which are applied to specific areas of toroidal cores. Therefore, the winding stray capacitance depends on the angle of the windings covering the core.