Research On Boost Converter Based On The Switched-Capacitor

Switched capacitor circuits(SCC)have been an important research field in power electronics all the time.In this paper,2 kinds of switching capacitor 2-times boost circuits,balanced SCC and unbalanced SCC,are the key research objects.This paper starts from analyzing the operational principles of 2 kinds of SCC,then the transient output voltage expressions in a switching period are given.Comparing theory and simulation of the output voltage waveforms verifies the correctness of the operational principle analysis.This paper presents equivalent circuit and derivation of equivalent resistance of SCC.Voltage gains and efficiencies of two SCC are compared,so as to draw a conclusion which SCC are better.The relevant theoretical and experimental results show that the balanced SCC presents better performance.The equivalent resistance of switched capacitor boost circuits is an important factor to determine the efficiencies of SCC and their load-carrying capacity.Based on the equivalent resistance model of switched capacitor circuit,this paper makes orthogonal analysis according to the three factors: switching frequency,capacitance and on-state resistance of MOSFET,and draws the conclusion that the on-state resistance of MOSFET is the most influential factor.SCC mentioned in this paper can not only realize AC-AC transformation,DC-DC transformation,but also can be used for wave conversions like triangular wave,square wave and trapezoidal wave.In this paper,a pulse power supply is used as the input to realize the multi-waveform conversion based on SCC.The limitations of multiwaveform conversion based on SCC are discussed,and the solutions are also provided.Realizing the multi-waveform conversions based on SCC,a novel triangular wave generator based on switched capacitor is proposed in this paper.The triangle wave generator can adjust the frequency and amplitude of the triangle wave without operational amplifier or feedback circuit.This paper presents the topological structure,the theoretical analysis of operational principle.The relations of proposed triangular wave generator parameters among peak-to-peak value,peak,valley,linearity and symmetry of triangular wave are discussed.Design methods of arbitrary parameters of triangular wave generators are proposed.The experiments are carried out to verify the feasibility of design methods.