The post discuses the how to make a 3 phase inverter circuit which can be used in conjunction with any ordinary single phase square wave inverter circuit. The circuit was requested by one of the interested readers of this blog.
The Circuit Concept
A 3 phase load can be operated from a single phase inverter by employing the following explained circuit stages.
Basically the involved stages can be divided into three groups:
- The PWM generator circuit
- The 3 phase signal generator circuit
- The mosfet driver circuit
The first diagram below shows the PWM generator stage, it may be understood with the following points:
The Oscillator and the PWM Stage
The IC 4047 is wired as a standard flip flop output generator at the rate of the desired mains frequency set by VR1 and C1. The 555 IC is configured as a PWM generator which sets the RMS of the 4047 output to the required degree by chopping the output transistor base signals.
The dimensioned push-pull PWM now becomes available at the E/C junction of the two BC547 transistors.
This PWM is applied to the input of the 3 phase generator explained in the next section.
The following circuit shows a simple three phase generator circuit which converters the above input push-pull signal into 3 discrete outputs, phase shifted by 120 degrees.
These outputs are further bifurcated by individual push-pull stages made from a NPN/PNP transistor stages. These 3 discrete 120 degree phase shifted, push pull PWMs now become the feeding input signals (HIN, LIN) for the final 3 phase driver stage explained below.
This signal generator uses a single 12V supply and not a dual supply.
Complete explanation can be found in this 3 phase signal generator article
The circuit below shows a 3 phase inverter inverter circuit stage using H-bridge mosfets configuration which receives the phase shifted PWMs from the above stage and converts them into corresponding high voltage AC outputs for operating the connected 3 phase load, normally this would be a 3 phase motor.
The 330 high voltage across the indivdual mosfet drivers sections is obtained from any standard single phase inverter integrated across the shown mosfets drains for powering the desired 3 phase load.
Full-Bridge Circuit using 3 Half-Bridge Drivers
UPDATE
ISSUES FOUND IN THE ABOVE 3 phase inverter circuit design
The above circuits are not entirely correct and needed a few serious corrections.
After reassessing the circuits I have come up with the following revised diagrams of a 3-phase inverter circuit.
Presently it's a square wave type, I'll soon explain how it could be converted into a modified pure sine wave simply by inserting a dimesioned PWM input to the shut down pins of the half bridge driver ICs.
The ground rail of all the circuits should be terminated into a common line.
Improved Oscillator Stage
3-Phase Generator Stage
The 3-Phase Full-Bridge Driver Stage
In the above 3 phase generator circuit (second last diagram) using a sine wave doesn't make sense because the 4049 would ultimately convert it into square waves, and moreover the driver ICs in the last design employ digital ICs which will not respond to sine waves.
Therefore a better idea is to use a 3 phase square wave signal generator for feeding the last driver stage.
You may refer the article which explains how to make a 3 phase solar inverter circuit for understanding the 3 phase signal generator stage functioning and implementation details.
Using IC IR2103
A relatively simpler version of the above 3 phase inverter circuit can be studied below, using the IC IR2103 half bridge driver ICS. This version lacks the shut down feature, therefore if you do not wish to incorporate the shut down feature, you can try the following simpler design.
Simplifying the Above Designs
In the above explained 3-phase inverter circuit, the 3-phase generator stage looks unnecessarily complex, and therefore I decided to look for an alternative easier option for replacing this specific section.
After some searching I found the following interesting 3 phase generator circuit which looks pretty easy and and straightforward with its settings.
Therefore now you can simply replace the earlier explained IC 4047 and the opamp section entirely and integrate this design with HIN, LIN inputs f the 3 phase driver circuit.
But remember you will have to still use the N1----N6 gates between this new circuit and the full bridge driver circuit
ABHISHEK Gupta says
Can I use 33883 ic is a h-bridge driver ic
In respect of other half bridge driver ic
Please sir I am very upset
Swag says
yes definitely you can use it….
ABHISHEK Gupta says
Sir how connect this
HIN and LIN in which pin
Sir can you provide the diagram
So kind sir
Swag says
Abhishek,
you will have to make a 3-phase generator circuit first and then feed the 3 phase signal to the HIN, LIN inputs of the IC.
ABHISHEK Gupta says
Sir I’m already complete three phase signal generations stage
But problems sir how connect HIN and LIN in which pin of 33883ic
Because thise is the new ic
Only one ic use or three ic use or how is as full bridge driver
Swag says
I am sorry, your IC is not a 3 phase driver, it is only a full-bridge driver IC, I mistakenly assumed it to be a 3 phase…if you are trying to search for 3 phase driver IC, then you must Google “3-phase driver IC”
By the way I had told you to search for a “half bridge driver IC” not full bridge IC…so please search for alternative “half bridge driver ICs” and then you can use 3 of these ICs to build a 3 phase inverter by integrating a 3 phase signals
ABHISHEK Gupta says
Sir
What is working of h bridge driver ic
After three phase generations stage
Why I can’t give these to mosfet
Please tell me sir and working of h bridge driver ic
Swag says
The driver IC performs complex processing for activating the high side mosfets, necessary for operating a full bridge network…without these operations a full bridge cannot work
ABHISHEK Gupta says
Sir what i do
Power driver ic2103 and any driver ic
Are not available in the market
Sir please give any other ic solution for three phase inverter 12v dc to 240v AC
Swag says
Abhishek, just Google “half bridge driver IC” you will be able to find many.
Bruno soares says
sir, I have seen a new diagram that you have designed, you can see that you do not need the ci 4049 to make the high and low outputs in the inverter design. I’m going to try this new circuit. the lady changed the ci before was an ir2110 now I see an ir2103 has any difference between them tks
Bruno soares says
Lord I’m sorry for writing because I’m Brazilian and we talked through translation on LINE so there may be difficulty understanding the words okay good night
Swag says
Bruno, It may work without 4049 but it is recommended for accurate functioning of the circuit, because the driver IC is a digital IC, therefore the input signals must be also perfectly digital or logical.
The two ICs are exactly similar, but IR2103 is the simpler version and it does not have the shut down pin, the IR2110 has the shut down pin option, so if you do not wish to include shut down feature, then IR203 can be used.
https://www.infineon.com/dgdl/ir2103.pdf?fileId=5546d462533600a4015355c7b54b166f
Aristarcus says
Dear sir, I have need a 24v dc to 400v ac 50 Hz 2kw inverter for induction motor. How possible to get it. There is a mosfet drive 3 phase inverter that you have given. May I use this circuit for my demand ? If possible, which quality mosfet need for output 400v ac / 2kw. Sir please help me. Thanks. Aristarcus.
Swag says
Hi Aristarcus, yes you can use the circuit for driving any 3 phase motor, just make sure the mosfets are appropriately rated as per the motor ratings
Bruno soares says
Thank you master, see if you’re sure I’ll do it okay.
1 calculate the resistor oara the voltage drop from 120 vac to 12 dc
2 put a rectifier diode on the end of each phase then I’ll enter the gates of ci 4049 for the alteas and low entrances ok ??
Swag says
That’s right Bruno, but after rectification to 12V DC the extra rectifier diodes will not be required.
Swag says
make sure to have 3 DC inputs sequencing alternately as per the 3-phase signal
Bruno soares says
Good morning sir I doubt in the three-phase generator circuit I saw that it found a simpler circuit in its searches I would like to know where I would enter the pwm pulse generator made with c i 4047
I can use the original circuit that you did with the ci 324 it works correctly ???
Swag says
Good Morning Bruno, the PWM pulse will need to be inserted to the low side mosfets, it cannot be inserted to the IC 4047 stage….first try the LM324 generator separately if you succeed then you can proceed.
Bruno soares says
Good morning, Mr. Swagatam, thanks for the help in the engine reversal !!
but I have another doubt I would use the circuit with a three-phase network could explain how the circuit would be because the three-phase simulator would be removed and would be only the ckt pwm and the high voltage
Swag says
Good morning Bruno, you can remove the entire 3phase generator stage and feed the HIN and LIN with rectified DC from the available 3 phase supply.
you can use resistive divider network for dropping the high 3 phase signal into 12V low voltage 3 phase signal and feed them across the HIN LIN inputs.
Bruno soares says
Good morning, I’m sorry for the posting of the article. I have a question with this circuit, how can I reverse this engine?
Swag says
for reversing the motor, you can reverse the 3 phase sequencing through a TPTT switch or 3 pole 3 way switch connected across the HIN, LIN inputs
ABHISHEK Gupta says
Sir output of LM 324 pin no 7,8,14 give output to six mosfet
What next step I do for voltage 240v at the output of three phase.
Power driver is necessary for this ?please tell me about this power driver ic
Swag says
Hi Abhishek, sorry what are you trying to make with the opamps? are you trying to make the 3-phase generator?…you will have to check/confirm each and every stage separately, very carefully and with full understanding otherwise you can never succeed…this project is for the experts who have advanced knowledge of electronics, so proceed with caution
ABHISHEK Gupta says
For generations HIN And LIN
Can we use transistor in replace of 4049
Swag says
you can do it, but make sure to add pull up resistors at the collectors.
ABHISHEK Gupta says
What I use In replace of ic 2103.
Any other name please say sir
Swag says
type “3 phase driver IC” and search online, you may find many other alternatives…
matt says
Good day please what circuit will I now use to convert 220vdc to 12vdc
Swag says
you can try the last circuit from this article
https://homemade-circuits.com/3v-5v-from-9v-using-diodes/
use MJE13005 for the transistor, 47K for the resistors, and also 47K for the preset…..use 2 watt resistors.
matamba2 says
Good day please can you give me a circuit that will convert 220vdc to 12vdc at 1amp maximum to be used in powering the
The PWM generator circuit
The 3 phase signal generator circuit
The mosfet driver circuit
thanks
Swag says
Hi, why do you need 1 amp for this? 50mA would be enough.
Chris says
Hi, good website and lots of innovative ideas. My question is this, Is it possible to design a simple 3 phase inverter that produces true sinwave output? I have a few old 3 phase machines that I would like to use. I don’t need a varible speed design and the motors are about 1kw each. What are your thoughts? Many thanks, Chris.
Swag says
Glad you liked the designs,
yes it can be designed and customized using the following concept
https://homemade-circuits.com/universal-esc-circuit-for-bldc-motors/
you can replace the IC 555 pwm stage with a SPWM stage and transform the design into a pure sine wave output
Chris says
Thanks for the speedy reply, I’m new to all this so please except my apologies for my ignorance , but how is the negative cycle of the Sine wave generated ? Many thanks for your patience.
Swag says
It is generated by the low side mosfets