## Pure Sine Wave Inverter Design

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Watters
Posts: 8
Joined: Wed Feb 22, 2017 1:59 pm

### Pure Sine Wave Inverter Design

I am designing a pure sinewave inverter, 220V, 50 Hz.
Here is the complete design,

without filter i simulate the whole circuit and tried to plot the current waveform by placing a current probe in RL Load (R = 5 Ohm, L = 16 mH).
I should be getting a sinusoidal current waveform but it is giving my arbitrary result. what might be the problem ?
Switching Frequency 16 Khz.
Fundamental Frequency 50 Hz.
http://tahmidmc.blogspot.com/2013/02...mode_2525.html
An external crystal is being used for 16 Mhz clock frequency.
here is the configuration i have done .

Here is the PWM waveform

Instead of IR2110 i have used IR2112, as IR2110 is not available in Proteus. MOSFET Driver circuit is working fine, i have checked the voltage at gate and it is turning it ON/OFF.
MOSFETS are working good.

If i directly filter the PWM signal using RC filter i am getting a sinusoidal voltage waveform.

What might be the problem that i am not getting sinusoidal current waveform ????
If someone interested in debugging my circuit or just wants to run it in their Proteus please tell i will attach the design file.

Here is what i am getting when simulate the circuit
Current waveform

Voltage Waveform

Any help will be appreciated

I wish tahmid is here to help me out, he is the best guy when it comes to share knowledge and helping out.

Junaid_Shahid
Posts: 110
Joined: Tue Feb 14, 2017 9:00 am

### Re: Pure Sine Wave Inverter Design

Watters wrote:
Fri Feb 24, 2017 1:41 pm
I am designing a pure sinewave inverter, 220V, 50 Hz.
Here is the complete design,

without filter i simulate the whole circuit and tried to plot the current waveform by placing a current probe in RL Load (R = 5 Ohm, L = 16 mH).
I should be getting a sinusoidal current waveform but it is giving my arbitrary result. what might be the problem ?
Switching Frequency 16 Khz.
Fundamental Frequency 50 Hz.
http://tahmidmc.blogspot.com/2013/02...mode_2525.html
An external crystal is being used for 16 Mhz clock frequency.
here is the configuration i have done .

Here is the PWM waveform

Instead of IR2110 i have used IR2112, as IR2110 is not available in Proteus. MOSFET Driver circuit is working fine, i have checked the voltage at gate and it is turning it ON/OFF.
MOSFETS are working good.

If i directly filter the PWM signal using RC filter i am getting a sinusoidal voltage waveform.

What might be the problem that i am not getting sinusoidal current waveform ????
If someone interested in debugging my circuit or just wants to run it in their Proteus please tell i will attach the design file.

Here is what i am getting when simulate the circuit
Current waveform

Voltage Waveform

Any help will be appreciated

I wish tahmid is here to help me out, he is the best guy when it comes to share knowledge and helping out.
I have experimented (in simulations) with different smoothing (filtering, snubber) networks. I have found it requires adding a capacitor. To be effective, two LC networks may be necessary.

I used a slow frequency (1.5kHz), to make the waveforms obvious. The capacitors are a larger value and they must carry heavy current pulses (in theory).
Your configuration is at a faster frequency, and it will use different values, and it may put less stress on the filter network.
Recommended Tutorial: Pure Sine Wave Inverter Simulation in Proteus

Audie57
Posts: 1
Joined: Sat Jan 26, 2019 4:27 pm

### Re: Pure Sine Wave Inverter Design

Some people seem to be of the opinion that a pure sine wave inverter is somehow better for charging laptop batteries than non-sine wave inverters. That seems wrong to me; I can't imagine why the THD of AC going into a digital power supply that puts out low voltage DC to charge a battery matters to the laptop that is running from the battery. Am I missing something? Thanks and check this