This paper presents a digital control scheme used in the control system of a bi-directional Dual Half-Bridge (DHB) converter over a wide range of operating conditions (load variations, input voltage changes). The proposed control scheme is a nonlinear current controller, where it enforces the current error of the high frequency transformer to converge to zero in a geometric progression. It offers higher stability, improved transient performance and increased robustness compared to the conventional control methods in DHB converters. Moreover, the proposed control scheme is a simple structure technique, which is easy to implement on digital microprocessors (e.g. DSP, FPGA). Simulation and experimental results show the superior performance of the GSC compared to other conventional control techniques.