Performance Comparison of Multi Input Capacitor Converter Circuits (original) (raw)

2018, International Journal of Electrical and Computer Engineering (IJECE)

This paper analyze the operation of a multi input switched capacitor (MIC) converters using a couple of switches, diodes and capacitors for several levels. With two input sources it is possible to obtain 8 output voltage levels. Here, 5 topologies of switched capacitor circuits namely summation, subtraction, inverting, double and half circuits are simulated and their performances are analyzed. Multi Input Converters have a high regard for multiple renewable energy sources used in smart grid systems, especially for distributed generators. The effects on output voltage with variation in load for different frequencies are also analyzed. Hardware implementation of summation and subtraction circuit is carried out and the results are compared with the simulated results 1. INTRODUCTION Inductors and capacitors are the main energy storage for the switched-mode power supplies (SMPS). The sizes are usually dominated by the inductor and transformer [1]. DC-DC converters play a vital role in renewable energy based applications [2], [3]. Resonant converters based on this SMPS can operate at high switching frequencies to decrease the size of the converters, however, their switching frequencies are not constant and hence the electromagnetic interference (EMI) filter cannot be optimized. Extended period quasiresonant converters have been introduced in [4], [5]. These converters are able to operate at constant switching frequencies and all the switching devices are switched at zero-current or zero-voltage. The requirement of magnetic components restricts the application and increases the difficulty in designing the converters. These difficulties were replaced with switched capacitor circuits. Switched-capacitor (SC) DC-DC power converters [6] are a subset of DC-DC power converters, using only switches and capacitors that can efficiently convert one voltage to another. Since SC converters does not have any inductors, they are ideal for integrated implementations, as common integrated inductors are not suitable for power electronic applications. The main advantage of this kind of converter is that no magnetic component is required for storing energy, making it possible to fabricate a smaller size and lighter weight converter in an integrated circuit [7]. There are very mature theories and techniques to design variety of DC-DC converters with single-input. Buck converter can for lower voltage than input [8], boost converter output higher voltage [9], boost-buck converter and Cuk converter can obtain the output voltage with step up or down ratio [10] In addition, Half-mode, Double-mode [11], step-up and step-down converter based on switched-capacitor can output half, twice and multiple and fractional voltage ratios [12], [13]. In recent years, with the continuous development