Boost current multilevel inverter and its application on single-phase grid-connected photovoltaic systems

Abstract

This work presents a novel current multilevel (CML) inverter topology, named boost CML inverter, and its application on energy processing of single-phase grid-connected photovoltaic (PV) systems. The structure allows a high power factor operation of a PV system, injecting a quasi-sinusoidal current into the grid, with virtually no displacement in relation to the line voltage at the point of common coupling among the PV system and the loads. The major appeals of using the CML technique are the balanced current sharing among semiconductor switches and the decrease of the current slope in the circuit devices, with a consequent reduction of conducted and radiated electromagnetic interference (EMI). The CML technique also allows adapting or minimizing current waveforms harmonic content. System description, mathematical approach, and design guidelines are presented, providing an overview of the new topology. In order to validate the proposed concepts, experimental measurements, made in a small-scale laboratory prototype, are also presented. The obtained results evidence the feasibility of the application of this new topology on singlephase grid-connected PV systems.Index Terms-Current multilevel (CML) inverter topology, electromagnetic interference (EMI), photovoltaic (PV) systems.

A Review on Recent Advances and Future Trends of Transformerless Inverter Structures for Single-Phase Grid-Connected Photovoltaic Systems

“…The authors of [79] suggested an inverter topology having 27 levels. Barbosa et al in [80] suggested a multilevel boost current inverter for grid-connected single-phase solar PV systems. In [81,82] different inverter topologies such as MOSFET inverter topology with H6-type technique, enhanced H6 topology, HB having a capacitor divider feature, HB designed with control circuit generation, H5 with optimized technology (oH5), grid connected multilevel inverter topology, high reliable and efficient (HRE) inverter topology, hybrid zero voltage rectifier topology (HR-ZVR), grid connected multifunction inverter topology, virtual DC bus topology, buck-boost converter, buck converter, boost converter, and related topologies for solar PV grid-connected applications were addressed.…”

“…In [81,82] different inverter topologies such as MOSFET inverter topology with H6-type technique, enhanced H6 topology, HB having a capacitor divider feature, HB designed with control circuit generation, H5 with optimized technology (oH5), grid connected multilevel inverter topology, high reliable and efficient (HRE) inverter topology, hybrid zero voltage rectifier topology (HR-ZVR), grid connected multifunction inverter topology, virtual DC bus topology, buck-boost converter, buck converter, boost converter, and related topologies for solar PV grid-connected applications were addressed. Comparison of numerous transformerless single-phase inverter topologies have been presented in [76][77][78][79][80][81][82], which are applied in grid-connected PV solar systems.…”

“…In comparison with FB-derived topologies because of the higher complexity, with ratings over 10 kW (mini-central) three-phase inverters these topologies are typically used. Besides, in the range of hundreds of kW, i.e., high power (central inverter), where multilevel inverters are too significant, these topologies are also very attractive [43,[76][77][78][79][80][81][82].…”

A Single-Stage Grid Connected Inverter Topology for Solar PV Systems With Maximum Power Point Tracking

“…4(a)]. For the th division of the grid voltage the following expression may be written: (4) To feed UPF sinusoidal power into the grid, the energy, that should be transferred during the th switching interval is (5) where is the amplitude of the current fed into the grid and is governed by the MPPT algorithm. ' ' is the switching time period.…”

Analysis of Symmetrical and Asymmetrical Current Source Multilevel Inverter

“…Multilevel inverters comprise of power semiconductors and DC voltage sources, the output of which creates voltages with stepped waveforms. The multilevel inverter configuration can be categorized into the Voltage Source Multilevel Inverter (VSMLI) and Current Source Multilevel Inverter (CSMLI) [4]- [6]. Multilevel VSI has DC voltage power source and produces an AC output to the load, whereas Multilevel Current Source Inverter delivers predetermine AC output from a single or more DC sources due to its high impedance DC power supply.…”