Abstract: With the rapid expansion of new energy vehicles, DC charging stations are required to operate under a wider range of output voltages, which places stricter demands on the design of DC–DC converters. Among various topologies, the LLC resonant converter is commonly adopted in charging systems due to its high efficiency, low electromagnetic interference (EMI), and electrical isolation. However, in practical applications, the achievable voltage regulation range is limited when only frequency modulation is applied, mainly because of the switching speed constraints of power semiconductor devices. As a result, the voltage gain increases slowly when the converter operates in the high-frequency region. To improve the voltage regulation capability under these conditions, a phase-shift control method operating at a fixed switching frequency is introduced. Compared with the conventional two-level LLC resonant converter, the three-level topology reduces the voltage stress across primary-side switching devices, which is beneficial for device selection and system reliability. In this study, a three-level full-bridge LLC resonant DC–DC converter is analyzed, and a hybrid control strategy combining frequency modulation and phase-shift modulation is employed to achieve wide-range output voltage regulation. In addition, load variations may lead to a slow transient response and fluctuations in the output voltage. To alleviate these issues, an active disturbance rejection control (ADRC)-based approach is adopted. Experimental results show that the proposed control scheme improves the dynamic behavior of the converter and contributes to better output voltage stability.