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Thank for letting me join the forum. I have just had a 50kw battery installed which has 3 extra MPPT inputs on the inverter and my solar is only 5kw and struggles to charge it. Conveniently my LG washing machine broke last week which provided me with a 36 pole DC motor and joined your group to ask advice. I wanted to rewire the stator, build a vertical wind turbine using 6 x 150mm PVC pipe halves and plug it into the MPPT inputs to help charge the battery.
Firstly, vertical wind turbine is the easiest to build and apparently quieter but unsure of measurements and potential RPM?
Secondly, which wiring configuration would be best suited for the turbine design?
I am possibly going down the wrong track but happy to receive any advice, recommendations or criticism .
If you wan to start with a VAWT lift machine, I advise you first to read my report KD 215 and KD 601. These reports can be copied for free from my website: www.kdwindturbines.nl at the menu KD-reports. I don't know exactly what generator you want to use but I suppose that originally it is a direct drive motor. This is a 3-phase AC motor but in the washing machine an inverter is used which suplies a 3-phase current with a varying frequency. These kind of motors can be used as generator for a wind turbine but they have a large disadvantage. If it has 36 armature poles, I expect that it has 27 stator steel poles and that a coil is wound around each stator pole. The coil sequence is U1, V1, W1, U2, V2, W2 and so on. If one armature pole is just opposite a stator pole, you will get a preference position. You wil get 108 rather strong preference position per revolution and this results in a rather large peak on the cogging torque. The rotor starts only at the wind speed for which it can supply this peak. It depends on the type and diameter of the rotor if the starting wind speed is acceptable. I have designed a rotor for a wind turbine which makes use of a bicycle front wheel motor which also has a large peak on the cogging torque (see KD 745). For such a large peak, you need a rotor with a low design tip speed ratio and very wide blades with a large blade angle.
I have looked about what I could find about such motors and I found pictures of a motor with 36 stator poles. One curved magnet is opposed to three stator poles but this magnet must be magnetized such that it has four poles. There are totally twelve of those magnets. So the armature has totally 12 * 4 = 48 poles. As the armature pole number determines the pole number of the motor, this is a 48-pole motor and not a 36-pole motor. The number of preference positions for this motor is 3 * 4 * 12 = 144. Edited 2026-02-27 02:13 by Adriaan Kragten
Thanks Adriaan for your response. You are clearly an extremely smart person with multiple degrees. I am a retired Airconditioning Mechanic trying to fashion a rudimentary wind generator made from a used washing machine motor and using other scrap materials in regional Australia with ideas gathered from several YOUTUBE videos. There are 10 different wiring configurations available on the Back Shed website i could choose but needed some advice on which would be the most effective with a home made vertical blade rotor.
If the winding of your generator is as I supposed in my second post, you have 36 coils wound arund 36 iron cores. The coil sequence is U1, V1, W1, U2, V2, W2, U3, V3, W3 and so on. I suppose that all twelve coils of one phase are connected in series but you have to check this by following the wires from coil to coil. This gives the highest DC voltage if the 3-phase current is rectified with a 3-phase rectifier. If this voltage is too high for what you want you can modify the winding by cutting the correct wires and making new connections. If you make two bundles of six coils and connect these in parallel, the voltage halves and the current doubles. Other options are three bundles of four coils, four bundles of three cols, six bundles of two coils and all twelve coils connected in parallel.
The first thing you have to do with your generator is to check if it really has 144 preference postions per revolution by rotating the armature very slowly and counting all peaks in one revolution. If you count 144 peaks, it means that the armature has 48 poles. You can also remove the stator and using a small magnet check if one curved magnet has really four poles.
The second thing you have to do is to measure the peak on the cogging torque. This can be done by connecting a rope at a certain arm with lenght r and adding weights to the end of this rope. This procedure is explained in KD 745. Once you know the peak on the starting torque in Nm, you have to design a windmill rotor which can supply this torque at lambda = 0 for a reasonable wind speed. Therefore at least you have to study my report KD 35 and KD 196. Matching is described in chapter 8 of KD 35. I also advise you to read the note: "Sequence of KD-reports for self-study" given at the top of the list with KD-reports. Designing a good wind turbine isn't simple and you need a lot of knowledge and experience to get a good result. Never build a windturbine without a proper safety system (see KD 485).
If you want a VAWT, a Darrieus rotor is no option because it has no starting torque. Then you can better take a 2-phase Savonious rotor (see KD 599). An alternative Savonious rotor with four buckets is described in KD 703. However, important disadvantages of Savonious rotors are that they require a lot of material and that it is impossible to limit the rotational speed and thrust at high wind speeds. Edited 2026-02-27 19:03 by Adriaan Kragten
Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.
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