The modified double-transistor forward converter based on combining one-cycle controller and PID controller

Due to the drawbacks of weak dynamic performance, high switching loses on switching devices and serious spike voltage across the flow-wheeling diode in the conventional double-transistor forward converter, a new kind topology named modified double-transistor forward converter is designed, and the working principle of the converter is analyzed in detail. To improve the proposed converter´s dynamic and static performance, a new control method named PID-OCC based on combining one-cycle controller (OCC) with PID controller are presented, and its control mechanism is investigated. Furthermore, the performance of the circuit system is researched by MATLAB/Simulink simulations. The results show that the proposed topology has the ability to switch at zero voltage, thus the switching losses and thermal stresses of switches and diodes are reduced, and the serious spike voltage across the flow-wheeling diode resulted in the reverse recovery interval is suppressed. Moreover, compared with the traditional OCC, the proposed PID-OCC can significantly improve the dynamic and static performances of the converter. And with the PID-OCC, the system´s capacity of resisting external disturbance is increased simultaneously.