Robust stabilizing digital controller for soft-switching zero voltage turn-ON H-bridge boost converter

In this paper a digital PID controller is designed for an H-bridge soft-switching boost converter. The digital PID controller is designed analytically using the discrete-time transfer function of the converter. Using this method, the PID controller gain range is obtained as a set of inequalities in two variables for a fixed third variable. By plotting the region enclosed by the inequalities the controller stabilizing region is obtained. By sweeping the third variable over its entire range, the complete stabilizing sets are obtained. The closed loop performance of the converter with the designed digital PID controller is simulated in Matlab-Simulink. A 75 Watt, 24 to 42 V, 50 kHz laboratory prototype closed-loop converter has been developed and then tested to validate the proposed digital controller design of the zero voltage turn-ON soft-switching boost converter.