FIG. 7a is a dynamic effect when the initial working state is standby for a flyback circuit to FIG. 4, when the control method jumps out of the HLT mode;

FIG. 7b is a dynamic effect of determining the initial working state by using a slope Kdown for a flyback circuit to FIG. 4, when the control method jumps out of the HLT mode.

Referring to FIG. 1, solid arrows are signal flows used by a control loop in a normal working mode, and dotted arrows and solid arrows are signal flows in a control loop in a dynamic mode.

A control method for improving dynamic response of switch power according to the present invention is based on a control system comprising a sampling module, a dynamic control module, an error calculation module, a PID module, a mode control module, and a PWM module, and the control system is connected to the controlled switch power to form a closed loop.

A sampling circuit in the sampling module samples the output voltage of the switch power to obtain the information of the output voltage information and input the information of the output voltage to the sampling calculation module, and the sampling calculation module obtains a signal Vo of the size of the output voltage according to a sampling algorithm, then the current sampling voltage Vo is inputted to the dynamic control module and the error calculation module, and the error calculation module calculates a current voltage error.