In this paper, a mathematical framework is presented to quantify the utilization of DC capacitors in resonant converters. The method begins by defining a base capacitor and dividing it into smaller elements, which are then distributed across all DC-capacitor locations in the circuit. The allocation is obtained through a Lagrangian-based optimization that forces all capacitors to operate under equal electrical stress, thereby minimizing total loss. After the capacitance distribution is determined, the voltage ripple of each capacitor is calculated. By combining the resulting ripple and loss values, a utilization metric is formed that allows fair comparison and ranking of different circuits, since all topologies are evaluated using the same total capacitor material. To demonstrate and validate the proposed method, several rectifier circuits commonly used in resonant converters were analyzed to identify the topology with the highest capacitor utilization. Three of these rectifiers were also implemented in hardware, and the measured results confirm that the proposed framework accurately predicts the performance of each circuit.
