A Simplified PWM Technique for Isolated DC-DC Converter Fed Switched Capacitor Multi-Level Inverter for Distributed Generation

Abstract

This paper presents a simplied PWM technique to drive switched capacitor type multi-level inverter fed from isolated type DC-DC converter for distributed generation. Distributed generation (DG) is renowned power generation at point of utility with no environmental a ects and reduces transmission line losses. Photovoltaic system is considered as renewable energy source for DG and the low voltage from PV system is boosted to required voltage using an isolated type single-input multi-output (SIMO) DC-DC converter. DC output from isolated SIMO DC-DC converter is fed to switched capacitor type multi-level inverter (SC-MLI) to feed the AC load. Isolated SIMO DC-DC converter apart from boosting the DG output voltage, also eliminates the problem of voltage unbalancing in SC-MLI topology. Closed loop operation of SIMO DC-DC converter employs only single PI controller instead of three controllers was presented in this paper. Modes of operation of SCMLI and PWM switching pattern were explained. Simulation of proposed system was developed using MATLAB/SIMULINK software.

Design and implementation of multilevel non-isolated DC-DC converter for variable DC voltage source

“…Though its drawback mentioned above, the number 995 of applications of the boost converter has recently increased due to its ability to handle high power values [10,11]. The multilevel DC-DC converters with multi-inputs have been addressed widely [12]- [15] as a possible solution for handling the DC-DC power conversion with minimum possible ripples and harmonics. Broadly, the authors in [16] have divided these types of converters into two main groups; the first group is the isolated multi-level converters, which includes transformers to isolate the sources from the load, and the second one is the non-isolated multi-level converters, which have more simple structure and relatively simple control method.…”