Inverters are an essential part in many applications including photovoltaic generation. With the increasing penetration of renewable energy sources, the drive for efficient inverters is gaining more and more momentum. In this paper, output power quality, power loss, implementation complexity, cost, and relative advantages of the popular cascaded multilevel H-bridge inverter and a modified version of it are explored. An optimal number of levels and the optimal switching frequency for such inverters are investigated, and a five-level architecture is chosen considering the trade-offs. This inverter is driven by level shifted in-phase disposition pulse width modulation technique to reduce harmonics, which is chosen through deliberate testing of other advanced disposition pulse width modulation techniques. To reduce the harmonics further, the application of filters is investigated, and an LC filter is applied which provided appreciable results. This system is tested in MATLAB/Simulink and then implemented in hardware after design and testing in Proteus ISIS. The general cascaded multilevel H-bridge inverter design is also implemented in hardware to demonstrate a novel low-cost MOSFET driver build for this study. The hardware setups use MOSFETs as switching devices and low-cost ATmega microcontrollers for generating the switching pulses via level shifted in-phase disposition pulse width modulation. This implementation substantiated the effectiveness of the proposed design.
A new three phase multilevel inverter with reduced number of components count is proposed in this paper. This inverter is designed using a single DC source per phase to generate multiple level output voltage which makes it suitable for low and medium voltage applications, including ac-coupled renewables or energy storages. A generalized circuit configuration is shown in this paper following which the number of output voltage level can be increased as per expectation. Although, each element endures the voltage stress equivalent to the input DC voltage, the value of total standing voltage (TSV) is reduced by the utilization of minimized number of components with respect to the number of series connected capacitors. Further, staircase modulation scheme is used to generate the switching signals. Hence, the proposed inverter can be operated at low switching frequency with optimal output current harmonic distortion which decreases switching losses and suppresses power factor falling. In order to validate the theoretical explanations and practical performances of the proposed inverter, the hypothesis is simulated for 9, 13 and 39 output voltage level inverters for three phase with a line voltage total harmonic distortion (THD) of 6.06%, 4.16% and 2.10% respectively in MATLAB/Simulink and a 5-level single phase laboratory prototype is implemented in the laboratory. INDEX TERMS Pulse width modulation inverters, multilevel inverters, total harmonic distortion, total standing voltage, photovoltaic systems, energy storage.
Power inverters are one of the devices of great importance used in power grids to convert DC to AC, especially for grids with attached solar panels or wind turbines. The world is getting warmer due to coal-and oil-based power generation. So human existence is threatened due to the increased amount of carbon-dioxide in the air. As a result, integration of renewable energy sources (RESs) with the grid became mandatory. So, the demand of grid-connected inverters is increasing as more RESs are connecting with the grid; this necessitates developing a low-cost grid connected inverter system. This paper presents a comprehensive study and hardware implementation of a grid tied inverter. In this research, we have demonstrated a cost-efficient grid tied inverter design using low cost DSP controller applying fixed point arithmetic. The fixed-point arithmetic and Digital Signal Processing (DSP) implementation results in superior performance over conventional methods of calculation. This paper also proposes a hardware model of such a bi-directional grid tied inverter.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.