Based on PI - sliding mode hybrid control of Wide-Output-Range LLC resonant converter

Aiming at the problem that the wide output voltage range and high efficiency of the traditional LLC resonant converter are difficult to be compatible, as well as the high-frequency jitter phenomenon in the steady-state state under the sliding mode control (SMC) and the slow dynamic response under the traditional Proportional - Integral (PI) control. For this purpose, a PI-sliding mode hybrid control (PI-SMC) strategy is proposed for a new type of LLC resonant converter with wide range output. This converter can actively adjust the duty cycle of the conduction signal of the secondary switch tube to broaden the range of output voltage. Meanwhile, an improved PI-SMC strategy was proposed to further expand the gain range and enhance the dynamic response capability. Finally, a simulation platform for the PI control, SMC, and PI-SMC of the new type of converter was established. Through experimental comparison, In the steady-state condition of PI-SMC, the high-frequency jitter phenomenon of SMC does not occur. Meanwhile, compared with PI control, it effectively reduces the overshoot of the system’s dynamic response and has a good control effect.