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I have been working for quite some time on my project to control the speed of a 220 V, 60 Hz, 0.35 A induction motor (domestic fan). I use an Arduino to generate 60 Hz with a switching frequency of 10 kHz. When I try my circuit with a 20 V motor, it works well and I can even vary the frequency.

But once I connect to 220 V the MOSFETs suddenly burn (explode) and the gate driver burns too. I came to understand that I don't have much knowledge of what is going on here.

Components used:

  • OPTO-ISOLATOR - 4N35
  • MOSFET - IRF830
  • GATE DRIVER - IR2113
  • BOOTSTRAP CAP (MLCC) - 47 μF
  • BOOTSTRAP DIODE - SCHOTTKY DIODE (400 V)

I have tried to achieve deadtime too, but still the same issue. I have converted AC to DC using a bridge rectifier, inductor (15 mH, 4 A), and DC link, (400 V, 2200 uF), then I fed this to my inverter.

Here is my attached inverter circuit design: NOTE: the Proteus design is my system overview, I couldn't simulate it there as I had trouble during simulation, actual components I have mentioned above.

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  • \$\begingroup\$ Realize that depending on the type of motor that is used in the fan it might be very complex to regulate it's speed. That 20 V motor is very likely a DC motor while the fan motor is likely an AC motor. Those motor types are very different. I would also highly discourage messing with 220 V when you have little idea of what's going on. \$\endgroup\$
    – Bimpelrekkie
    Commented Nov 30, 2021 at 8:53
  • \$\begingroup\$ Thank you @Bimpelrekkie, I have studied how I can achieve this, then I had to conduct research, that's the reason I'm working on it. I wish to learn this too. I believe it can be a good step for me even though it is dangerous, haha. \$\endgroup\$
    – John Claude
    Commented Nov 30, 2021 at 8:59
  • \$\begingroup\$ .35A, it is a domestic fan. just for air circulation, so no heavy load on it, 75Watts. \$\endgroup\$
    – John Claude
    Commented Nov 30, 2021 at 9:14
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    \$\begingroup\$ Using a gate driver with ~25ns rise/fall times on a perfboard like that is asking for problems. Do you have a scope? It's probably ringing like crazy. \$\endgroup\$
    – Unimportant
    Commented Nov 30, 2021 at 9:16
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    \$\begingroup\$ Your schematic indicates no isolation between Arduino and mains side. And where does the 15V come from? The U2 VS and HO are incorrectly connected to Q1, right? And you do realize the node that has the GND symbol will vary between 0V and -310V as per the incoming mains sine wave? \$\endgroup\$
    – Justme
    Commented Nov 30, 2021 at 10:13

1 Answer 1

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I immediately see a problem. Gate drive for Q1 from pin 7 of U2, is shorted to Q1 source! Q1 source should connect to pin 5 of U2, and the gate of Q1 should drive from pin 7.

I suggest review your design for similar mistakes as a first step.

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  • \$\begingroup\$ (I can see the short in the schematic. can you pinpoint column&row designations if it is in the PCB's solder side, too?) How do you explain with a 20 V motor, it works well? \$\endgroup\$
    – greybeard
    Commented Jun 27, 2023 at 5:19
  • \$\begingroup\$ If your schematic and layout do not match that is another problem. I cannot follow that breadboard. \$\endgroup\$
    – user144532
    Commented Jun 27, 2023 at 6:41
  • \$\begingroup\$ As for why it is failing at high voltage, there are many possible problems. Ringing, miller effect, lack of output filtering (self-capacitance of the motor will be significant at switching frequency), inductive load of the motor (reactive power will be returned to the supply), modulation depth too high so your bootstraps stop working, lack of isolation (clearance distance on PCB) between nodes at different voltages... Just a few. Diagnostics require, differential voltage probes, DSO/CRO, current probe, limited current DC supply, resistive test load. \$\endgroup\$
    – user144532
    Commented Jun 27, 2023 at 8:13

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