Dynamic Modeling Of PWM Plus Phase-Shift (PPS) Bidirectional DC-DC Converters

With development of sience and technology, bidirectional DC-DC converters will be widely used in applications such as DC uninterruptible power supplies, aerospace power systems, electric vehicles and advanced mobile generator sets.PWM plus phase-shift (PPS) control technique is a technique combining PWM control technique and phase-shift control technique. The PWM control of duty cycles acts as an electric transformer which regulates the amplitudes of equivalent input voltage and equivalent output voltage, so that both positive and negative amplitudes of equivalent input voltage are equal to those of equivalent output voltage. Compared with phase-shift control, PWM plus phase-shift control can reduce the current stresses and RMS currents of the converter. The loss of the converter can also decrease. It is proved the converter can achieve ZVS in larger load variation.In order to improve converters' dynamic characteristic, we should design the feedback system to establish closed loop system. Recently, the main modeling technique for bi-directional DC-DC converters is state-space average technique and the modeled system are all one regulating parameter controlled system. PWM plus phase-shift (PPS) control bidirectional DC-DC converters have two regulating parameters, that is duty cycle D and phase-shift angles Φ. In order to analize the converters and design control system, the paper established small-signal dynamic model for PWM plus phase-shift (PPS) control bi-directional DC-DC converters, based on the present study.Take a PWM plus phase-shift (PPS) control bidirectional DC-DC converter for example, The paper modeled for the converter. Simulation results and experimental results also hase been done to qualified the dynamic model...