Title |
Analysis of ZCS Operation Characteristics of GaN FET-based IPT System |
Authors |
안철용(Chul-Yong Ahn) ; 김종수(Jong-Soo Kim) |
DOI |
https://doi.org/10.5370/KIEE.2020.69.9.1356 |
Keywords |
GaN FET; Inductive power transfer; ZVS; ZCS; Reverse recovery charge; Reverse recovery current |
Abstract |
This paper presents the feasibility of GaN FET as a method to solve the problems caused by bifurcation of IPT system. In the IPT system, bifurcation can occur for various reasons, and when bifurcation occurs, the operating area is shifted from ZVS to ZCS. In this process, the large reverse recovery charge of the MOSFET causes a very large current spike, which can cause the device to burn out. To avoid this, an additional sensor and a switching frequency shift algorithm must be applied. To solve this, the characteristics of the GaN FET, which is known to have a reverse recovery charge amount close to 0, are compared with that of a silicon MOSFET, and the spike current generation during ZCS region transition due to bifurcation is analyzed through simulation. The validity of the analysis is verified experimentally through a 2 kW prototype IPT system, and the experimental results shows that the current spike generated under bifurcation conditions is reduced by about 75% compared to the silicon MOSFET. |