A transformerless common ground‐based 1‐ϕ single‐stage switched boost inverter for solar photovoltaic applications

Abstract

This paper proposes a transformerless common ground based single phase single‐stage switched boost inverter for solar photovoltaic (PV) applications. In the proposed inverter, the input DC source and output AC load share a common ground. As a result, the high‐frequency common mode voltage across the parasitic capacitance is eliminated, resulting in negligible leakage current ( ) and the associated power loss, and harmonics in the inverter. Moreover, the higher voltage gain of the inverter facilitates the inverter to operate with high modulation index and lower shoot through (ST) duty ratio. Hence, the DC link voltage requirement across the inverter leg is reduced. Consequently, the voltage stress across the switches is minimized. Here, a modified PWM control technique is adopted, where the dual active states of the proposed inverter reduce the inductor current ripple and make it suitable for solar PV applications. The voltage boosting capability of the proposed inverter is extendable with the help of an additional number of intermediate impedance sub‐networks. The detailed steady‐state analysis of the proposed inverter is verified with the help of MATLAB simulation. To verify the simulation results, a 200 W, 120 V, and 50 Hz experimental prototype is developed. The prototype is tested for unity and lagging power factor load conditions with a wide range of input DC voltages, and all the major results are included in the paper. The power and thermal loss analysis is carried out using PLECS software, and the results show that the inverter has a maximum efficiency of 97.48%. From the experimental results, it can be inferred that the proposed inverter has a higher modulation index, lesser inductor current ripple, and zero leakage current as compared to the contemporary inverters.

A New Boost Topology Seven-Level Inverter of High Voltage Gain Ability and Continuous Input Current With MPPT for PV Grid Integration

“…The peak voltage and current can also be measured. The datasheet specifies the switching energy to calculate the power switch's average turn-on and turn-off loss as expressed in (28). (28) where is ipeak (n) and vpeak (n) are the current and peak voltage measured at n th rising and falling edges of voltage, respectively.…”

“…The datasheet specifies the switching energy to calculate the power switch's average turn-on and turn-off loss as expressed in (28). (28) where is ipeak (n) and vpeak (n) are the current and peak voltage measured at n th rising and falling edges of voltage, respectively. fEon and fEoff are the switching energy function corresponding to the peak voltage and current when the power switch is turned ON and OFF, respectively.…”