ELECTRIC TRANSMISSION DELTA /WYE and SERIE/PAPALLEL stator

[FFR Trikes]

Hi Arlo,

I ask because I took interest in the subject when Doctorbass first posted in 2009, and we did a lot of testing and found it to be very useful, especially on sensorless systems. We see more torque and efficiency in Wye, and of course much more speed in Delta. We spent a whole lot of time and money and made a PCB that does the switching. Thought someone here may be excited to know that it finally exists!

I'm also curious to think of other applications for simultaneous switching of multiple high current loads (up to 100A) with very low resistance. The board was super expensive to develop, and I'm trying to think of other industries that it might be useful in.

Tommy

 

[Arlo1]

Hi Arlo,

I ask because I took interest in the subject when Doctorbass first posted in 2009, and we did a lot of testing and found it to be very useful, especially on sensorless systems. We see more torque and efficiency in Wye, and of course much more speed in Delta. We spent a whole lot of time and money and made a PCB that does the switching. Thought someone here may be excited to know that it finally exists!

I'm also curious to think of other applications for simultaneous switching of multiple high current loads (up to 100A) with very low resistance. The board was super expensive to develop, and I'm trying to think of other industries that it might be useful in.

Tommy

The reason you see those results is most likely from the limitations of the controller.

If you controller can only put in x amount of amps but your motor can handle more you would see a Gain in torque when wound/connected in WYE. But if your controller is not the bottle neck then it will make no difference.
The motors limits are not determined by a WYE vs detla winding/connection as long as both have the same copper fill.

A motor in delta can make just as much torque as a motor in WYE but the controller will have to handle 1.73* more phase current.
If you see any change in efficiency its related to the controller and the current rise time/PWM frequency or simply put the controllers ability to control current smoothly.

 

[liveforphysics]

If you put the same added mass of the delta/wye switching apparatus towards more mosfet die area in the controller, you end up with higher performance and efficiency.

Motors stator/rotor geometry can only be designed for sinus BEMF in either WYE or Delta, but not both. This means if your motor works equally well for both, it's not a motor optimized for either.

If the goal is to send cash after higher performance, spending it on a motor rotor position encoder and a controller with adequate phase current and field weakening is how you win.