Research on CLLC resonant converter control hybrid strategy based on OMA

The symmetric CLLC resonant converter permits the flow of energy in both directions with identical converter structures, while maintaining the characteristics of the original LLC resonant converter. The fundamental harmonic approximation (FHA) is often used to analyze resonant converters. Its advantage is its simplicity and intuitive nature. However, its accuracy is only maintained near the resonant frequency. Therefore, the choice of modal analysis method, according to the actual operation of the circuit, is essential for accurately describing the circuit’s operating state and gain characteristics. The control strategies that are more frequently employed in CLLC resonant converters can be classified into two principal categories: frequency control and phase-shift control. This paper presents a hybrid control strategy based on frequency control and double phase shift control, and a simulation circuit is constructed for the purpose of verifying the circuit.