표 2. | Table 2. WPT 시스템의 S-S, S-P, double-sided LCC 토폴로지의 장점, 단점 | Advantages and disadvantages of S-S, S-P, and double-sided LCC topologies of WPT system.

Type	Advantage	Disadvantage
S-S	Sinusoidal constant current output (I_out), so the RX rectifier input power factor is high. Simple and low loss. The phase difference between I₁ and I₂ is close to 90 degrees. Resonant network is not dependent on load or mutual inductance. Bidirectional WPT operation is possible.	At no load, the TX side becomes a short circuit. ZVS may not be secured depending on load and coupling coefficient change.
S-P	Constant voltage output (V_out) regardless of the load. Simple and low loss Simple and low loss (low ESR due to small number of elements).	The phase difference between I₁ and I₂ is not close to 90 degrees. TX resonant capacitance (C₁) depends on mutual inductance. At no load, the RX side becomes a short circuit. ZVS may not be secured depending on load and coupling coefficient change.
Double-sided LCC	TX coil current (I₁) is a constant current. Sinusoidal constant current output (I_out), so the RX rectifier input power factor is high. The phase difference between I₁ and I₂ is close to 90 degrees. Resonant network is not dependent on load or mutual inductance. Bidirectional WPT operation is possible. ZVS is secured even when load and coupling coefficient change.	Many devices are included in the resonance network, which is disadvantageous in terms of volume and price. Many devices are included in the resonance network, which is disadvantageous in terms of the power loss due to ESR.