High-Efficiency MOSFET Transformerless Inverter for Non-isolated Microinverter Applications


Best in class low-control level metal– oxide– semiconductor field-affect transistor (MOSFET)- based transformerless photovoltaic (PV) inverters can achieve high capability by using latest super convergence MOSFETs. In any case, these MOSFET-based inverter topologies encounter the evil impacts of no less than one of these drawbacks: MOSFET disillusionment danger from body diode pivot recovery, extended conduction incidents as a result of more devices, or low magnetics use. By part the conventional MOSFET based stage leg with a streamlined inductor, this paper proposes a novel MOSFET-based stage leg plan to restrict these burdens. In light of the proposed stage leg structure, a high viability single-arrange


MOSFET transformerless inverter is shown for the PV microinverter applications. The pulsewidth change (PWM) direction and circuit undertaking rule are then portrayed. The ordinary mode and differential-mode voltage show is then displayed and analyzed for circuit structure. Exploratory outcomes of a 250Whardware model are seemed to show the advantages of the proposed transformerless inverter on non-isolated two-sort out PV microinverter application.



Fig. 1. Two-stage nonisolated PV microinverter.



Fig. 2. Proposed transformerless inverter topology with (a) separated magnetic and (b) integrated magnetics.



Fig. 3. Output voltage and current waveforms.


Fig. 4. PWM gate signals waveforms.


Fig. 5. Inverter splitting inductor current waveform.


Fig. 6. Waveforms of voltage between grid ground and DC ground (VEG ).


This paper proposes a MOSFET transformerless inverter with a novel MOSFET-based stage leg, which accomplishes:

1) high proficiency by utilizing super intersection MOSFETs and SiC diodes;

2) limited dangers from the MOSFET stage leg by part the MOSFET stage leg with streamlined inductor and limiting the di/dt from MOSFET body diode switch recuperation;

3) high magnetics use contrasted and past high proficiency MOSFET transformerless inverters in [21], [22], [25], which just have half magnetics use.


The proposed transformerless inverter has no dead-time necessity, basic PWM regulation for usage, and limited high-recurrence CMissue. A 250W hardware model has been planned, created, and tried in two-arrange nonisolated microinverter application. Exploratory outcomes exhibit that the proposed MOSFET transformerless inverter accomplishes 99.01% pinnacle effectiveness at full load condition and 98.8% CEC productivity and furthermore accomplishes around 98% attractive use. Because of the benefits of high effectiveness, low CM voltage, and enhanced attractive use, the proposed topology is alluring for two-organize nonisolated PV microinverter applications and transformerless string inverter applications.