“Report KD 718 can be copied for free from my website: www.kdwindturbines.nl at the men KD-reports. The title of this report is: “Ideas about a 16-pole, 3-phase permanent magnet generator using the housing and winding of a 4-pole asynchronous motor frame size 100”.
This report describes a way how to modify a standard 4-pole, 3-phase asynchronous motor such that it can be used as a PM-generator for a wind turbine for 24 V or 48 V battery charging. Manufacture of the new armature is rather easy as the magnet grooves are wide and shallow and in parallel to the armature axis. The magnet costs are low as only a rather small magnet volume is used. Mechanically the armature has sixteen poles but physically it has four poles and therefore it can work together with the standard winding of a 4-pole motor. The flow pattern is given in figure 2. The armature pole angle is 2.5° larger than twice the stator pole angle and the fluctuation of the sticking torque is therefore almost flattened. A front and a side view of the armature and the stator is given in figure 1.
Adriaan Kragten”
New message from Adriaan in 2013 as follows:
“A new chapter 7 has been added to my public report KD 718 which can be copied for free from my website: http://www.kdwindturbines.nl at the menu KD-reports. The title of this chapter is: “Use of a 4-pole motor frame size 100L and a 32-pole armature. The armature has 32 mechanical poles but 4 magnetic poles and can therefore be used in combination with the standard 3-phase winding of a 4-pole, 3 kW asynchronous motor. The armature has 244 preference positions per revolution and the peak on the cogging torque will therefore be very low. I think that this is the simplest and cheapest way to modify an asynchronous motor into a PM-generator.
Adriaan Kragten”