| With higher and higher requirement on the performances of switching power supply, linear control techniques of switching converters based on traditional Pulse Width Modulation (PWM) are seriously challenged by transient characteristics and robustness resuirement. In order to enhance the performance of switching power supply, it is necessary to introduce nonlinear control with better control performance.A new nonlinear control technique, pulse train (PT) control technique of switching dc-dc converters in discontinuous conduction mode (DCM) is described in the thesis. The operation principle and characteristics of voltage mode and current mode PT control are analyzed in detail. The energy model, control pulse combination and output voltage ripple of PT controlled DCM switching dc-dc converters are also analyzed in detail. Simulation and experimental results are presented to verify the theoretical analysis results.A novel control method Pulse Skip Modulated Pulse Train (PSM PT) control is presented in this thesis. PSM PT with Voltage ripple control (VRC) and load current control (LCC) are analyzed. The efficiency at light load can be improved with PSM PT control. The analysis results are verified through simulation and experimental results.PT control technique is applied to the control of Pseudo Continuous Conduction Mode (PCCM) swithing converter, which increases the load capacity of the converter. The control method is analysised in detail and the control circuits are designed. Simulation and experimental results are performed to verify the theoretical analysis results.
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