This project presents a high-reliability single-phase transformer less grid-connected inverter. Both unipolar and bipolar SPWM techniques are used. A 1-kW prototype was simulated and tested to verify the theoretical analysis of the project. The inverter is designed for high efficiency, small size, light weight, and low cost grid connections for single-phase PV systems.

1. Under The Guidance Of Submitted By
Mr.M.SRIRAM KIRAN(M.Tech) M.RAVI KUMAR 11X61A0263
Associate professor

2. • This project presents a high-reliability single-phase
transformer less grid-connected inverter .
• Both unipolar spwm and bipolar spwm techniques are
used.
• a 1-kW prototype has been simulated and tested to
verify the theoretical analysis of this project.

3. • Nowadays, the gird-connected photovoltaic (PV) systems,
especially the low-power single-phase systems.
• This system for high efficiency, small size, light weight,
and low-cost grid connected inverters.
• A common-mode leakage current flows through the
parasitic capacitor between the PV array and the ground
once a variable common-mode voltage is generated in
transformer less grid-connected inverters

6. • (a) H5 inverter.
• (b) HERIC inverter.
• (c) Full-bridge inverter with dc bypass.
• (d) High-efficiency inverter with H6-type
configuration.
• (e) Kerstin inverter.
• (f) Inverter with two paralleled buck converters.

8.  Off-line or pre-calculated PWM technique .
 Hysteresis control PWM
 Carrier based PWM.

12.  low cost
 Less space required
 Renewable energy source
 Constructed easily