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I'm trying to make a DIY wind turbine generator from a 3ph squirrel-cage induction motor but I'm having trouble matching the generator with the rectifier with the inverter. I'm not sure which parameters I must look for when matching. Also, I was wondering if this connection would work

approximate scheme for self excitation for the induction motor

P.S.: I attached an approximate scheme for self excitation for the induction motor

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    \$\begingroup\$ Looks like asynchronous induction motors. Those won’t work as a generator. What you want is a permanent magnet motor/generator. \$\endgroup\$
    – winny
    Dec 25, 2021 at 10:19
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    \$\begingroup\$ It can be operated as a generator once it reaches a higher rpm than the synchronous speed with a 50 HZ frequency and a 4 pole generator 1500 rpm synchronous speed this would prove to work \$\endgroup\$ Dec 25, 2021 at 10:32
  • \$\begingroup\$ Which you will generate and inject how? \$\endgroup\$
    – winny
    Dec 25, 2021 at 11:51
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    \$\begingroup\$ The question is too broad to answer in this forum. You need two inverters. You need a 3-phase, variable-frequency, regenerative inverter that can supply reactive VA for motor excitation while receiving power generated over the range of speeds defined by the characteristics of the wind turbine and the range of wind speeds expected. If you want to produce single-phase AC power for use, you need a second inverter for that. The 3-phase inverter should probably have a 3-phase rectifier built into it. \$\endgroup\$
    – user80875
    Dec 25, 2021 at 14:31
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    \$\begingroup\$ Before being concerned about matching parameters, you need to be concerned about understanding the basic system operation. \$\endgroup\$
    – user80875
    Dec 25, 2021 at 14:43

1 Answer 1

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This is not going to work.

The inverter is not designed to generate the excitation required to use an induction motor as a generator and the proposed design doesn't appear to have any other way to do so. End of story.

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  • \$\begingroup\$ I appreciate the downvote. Bad news is not welcome. However, until the problems in the proposed scheme are addressed (yes, excitation is not the only one, an efficient 1:100 step-UP gearbox is ... problematic) it's the answer to the "also" part of the question. \$\endgroup\$
    – user16324
    Dec 25, 2021 at 14:24
  • \$\begingroup\$ This "answer" should be posted as a comment, not an answer. \$\endgroup\$
    – user80875
    Dec 25, 2021 at 14:40
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    \$\begingroup\$ @CharlesCowie Though it is a concrete answer to the "also" part of the question, without which the rest is academic. Conversely, I think your comments are suitable for an actual (and better) answer. \$\endgroup\$
    – user16324
    Dec 25, 2021 at 14:44
  • \$\begingroup\$ As i previously stated, I plan on adding a capacitor unit at the output terminals of the induction generator; it will supply the reactive power needed to generate a voltage at the output terminals of the induction generator. This would generate a residual flux or magnetic field in the stator coil at the induction generator. The voltage generation process will not occur if there is no residual flux. To get maximum power output from the generator the capacitance value must change appropriately, and for that, Induction Generator Control (IGC) is needed \$\endgroup\$ Dec 25, 2021 at 20:22
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    \$\begingroup\$ Efficiency losses. But I'll give you one hint : where high step-up ratio gearing is common, it's done with cycloidal tooth forms - or even lantern pinions, to avoid the friction arising from the pressure angles in involute teeth. You'll find these in clocks. But note this results in weaker roots. If I had to step up 100:1 I'd consider an involute stage followed by cycloids. But practically I wouldn't. For the few kW you're looking at, I'd use axial field ironless PM, and direct drive, both for efficiency and reliability. I recommend Hugh Piggott's designs; well proven in NW Scotland. \$\endgroup\$
    – user16324
    Dec 25, 2021 at 21:13

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