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An article on power to weight ratio in switched electronic motor control design.

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Peter Taylor:
This article explains why the Delta and Star configurations have one third less power to weight ratio than an Open configuration in switched electronic motor control design.

Definitions:

Power to weight ratio is the amount of power produced in one revolution of the rotor compared to the weight of copper wire in the stator windings.

Diagram 1 shows a Delta configuration, and the truth table shows the eight ways the three windings can be driven. A one for connection A and a one for connection B means that A and B are at the same voltage level and there is no voltage across stator winding AB (as highlighted).
This means that one of three windings is never utilized in producing power in a revolution, giving 2/3 of the maximum power to weight ratio.

Diagram 2 shows an Open configuration, and the truth table shows that there are sixty four ways to drive the windings, and all windings can be made to produce power in one revolution, giving a maximum power to weight ratio.

QED

langwadt:
what it shows is that you don't understand how three-phase motors work ....

rob77:
not again !  |O


--- Quote from: Peter Taylor on June 14, 2022, 06:04:51 pm ---This article explains why the Delta and Star configurations have one third less power to weight ratio than an Open configuration in electronic motor driver design.
Definitions:
Power to weight ratio is the amount of power produced in one revolution of the rotor compared to the weight of copper in the stator windings.

Diagram 1 shows a Delta configuration, and the truth table shows the eight ways the three windings can be driven. A one for connection A and a one for connection B means that A and B are at the same voltage level and there is no voltage across stator winding AB (as highlighted).
This means that one of three windings is never utilized in producing maximum power in a revolution, giving 2/3 of the maximum power to weight ratio.

Diagram 2 shows an Open configuration, and the truth table shows that there are sixty four ways to drive the windings, and all windings can be made to produce power in one revolution, giving a maximum power to weight ratio.

QED

--- End quote ---

please elaborate on the "all windings can be made to produce power in one revolution" ...  :popcorn:

rob77:

--- Quote from: langwadt on June 14, 2022, 06:18:52 pm ---what it shows is that you don't understand how three-phase motors work ....

--- End quote ---

he already had a thread with this crap the other day ;) and yes he's totally lost and has absolutely no clue how 3phases work.

Miyuki:
Of course, the third winding is just laying around because all engineers for 150 years were totally dumb
And if you add three more windings you can even create more energy than the motor consumes and turn it into a magical free energy device, or maybe attach it to a carpet to build a flying carpet 

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