This document describes a pure sine wave single phase inverter. It uses SPWM (sine pulse width modulation) switching technique to convert DC to AC and produce a pure sine wave output. The inverter consists of an H-bridge of MOSFET transistors controlled by a microcontroller to generate PWM signals. It provides advantages like reducing harmonics, increasing efficiency, and producing a pure sinusoidal waveform compared to a square wave inverter. Applications include electric fences, aircraft power supplies, UPS systems, and induction heating.

2. Pure Sine Wave Single Phase Inverter
Abuzar Uzair Hasnain Hamza Hummayun
SP15-BEE-096 SP15-BEE-106 SP15-BEE-100 SP15-BEE-029 SP15-BEE-127

3. Contents
3
1. Problem Statement.
2. Introduction.
6. Working.
3. Components.
4. Block Diagram.
5. Circuit Diagram.
7. Advantages.
8. Applications.
9. Simulation.

4. 3
Problem Statement
Square wave inverter produces greater number of
harmonics which produces heating effect and can
results in damage of our electronic appliances.

5. Fig 1 SPWM
Introduction
 Sine Pulse Width Modulation (SPWM)
switching technique is used.
 Conversion from the DC-to-AC.
 It is widely used in power electronic
applications.
 Comparison of reference sine signal with
carrier signal.
 When reference signal is greater than
carrier switch is will be on.

6. 3
Sine PWM Full bridge Inverter
Overview

7. Working 7
S.no Components
01 Transformer
02 Microcontroller
03 DC Supply
04 Mosfet
05 Capacitor
06 Gate Drive IC
Table 01: Components

8. Block Diagram
8
Fig 2 Block diagram of Pure SineWave Inverter

9. Circuit Diagram
9
Fig 3 Circuit Diagram of Pure Sine Wave Inverter.

10. 6
Working 1/2
 This inverter consists of a four
Mosfet transistors which are used
for switching purpose.
 Two Mosfets (M1& M4) are
triggered together for same gate
signal (+ve pulse) and other two
Mosfets (M2& M3) are triggered
together for -ve pulse.
Fig 4 H-Bridge

11. 6
Working 2/2
 Microcontroller is used to generate the required PWM signals to drive and switch the
H-bridge Mosfet transistor.
 Switching at the sinusoidal PWM (SPWM) control frequency of 16 kHz at a half cycle
which takes 10ms.
 Two diagonal of the full H-bridge simultaneously
at one of the two halves and the other two
diagonal MOSFET (IRL 540N) at the other halves
producing pure sine wave which is given to the
transformer and step up to 220V/50Hz .
 Dead time is reduced.

12. Advantages
 Reduces the number of
harmonics.
 Attain the optimum
dead time.
 Increases the overall
effeciency.
 Producing pure sinusoidal
wave .
 Increases the Vrms value
of the system.
Advantages

13. 17
Applications
 Electric fence Pumping Water
Aircraft power supply Induction Heating
 UPS
Applications

14. 3
Simulation

15. 3
Simulation Waveforms

16. 3
Conclusion
o The SPWM technique is used to control the inverter switch. This
method is superior to other methods because it improves the
quality of the output waveform.
o The dead time is reduced from 180μs to 63μs which increases the
overall Vrms.
o The efficiency of the inverter is increased to large extent due to
pure sine wave at output which reduces total harmonic distortion
(THD).

17. Thank You !!!