<p>To address the issue of LLC resonant converters not being able to operate evenly and stably when combined and connected as modules for wide-range, single-stage operation, this study proposes a voltage sharing control method for an input series output parallel (ISOP) connection system, employing an LLC converter as the basic module. The hybrid charge-based control applied in the proposed method enhances the dynamic output response of the ISOP system. The method features a master–slave structure; a hybrid charge control is applied to the master module, which calculates the frequency provided to all slave modules. The ISOP system inherently maintains balance among modules without the need for a dedicated control loop for sharing. Steady-state and dynamic mathematical models of the ISOP system, which describe the voltage sharing mechanism of the resonant converter after combination, are derived. A prototype comprising LLC half-bridge modules is constructed in the laboratory, and experimental results are obtained to verify the system’s steady-state and dynamic performance. The research results hold significant importance for advancing the application of LLC topologies in combination techniques.</p>