Control method for resonant conversion circuit

A control method for a resonant conversion circuit, wherein the resonant conversion circuit comprises a switching circuit, a resonant network and a rectifier circuit, the switching circuit, the resonant network and the rectifier circuit are connected successively, the resonant network comprises a resonant capacitor and a resonant inductor, the control method comprising steps of:

• (S0) determining a starting point of an operating trajectory according to a sampling data at a first switching time point, wherein the operating trajectory comprises a first trajectory segment of N trajectory segments, and N is a positive integer;
• (S1) determining an initial operating mode of the resonant conversion circuit according to a starting point of the first trajectory segment of the N trajectory segments, wherein the starting point of the first trajectory segment is the starting point of the operating trajectory;
• (S2) setting the first trajectory segment as a current trajectory segment, and setting the initial operating mode as a current operating mode;
• (S3) predicting a curve of the current trajectory segment and an end point of the current trajectory segment according to the current operating mode;
• (S4) calculating a time duration of the current trajectory segment;
• (S5) determining whether the end point of the current trajectory segment is an instruction point complying with a control instruction, wherein if a determining condition of the step (S5) is not satisfied, a step (S6) is performed, wherein if the determining condition of the step (S5) is satisfied, a step (S10) is performed;
• (S6) setting the end point of the current trajectory segment as a starting point of a next trajectory segment;
• (S7) determining a next operating mode of the resonant conversion circuit according to the starting point of the next trajectory segment;
• (S8) setting the next trajectory segment as the current trajectory segment, and setting the next operating mode as the current operating mode;
• (S9) performing the step (S3) again;
• (S10) setting the instruction point as an end point of the operating trajectory, and calculating an execution time from the starting point of the operating trajectory to the end point of the operating trajectory;
• and
• (S11) determining a second switching time point according to the execution time.