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Star and Delta motor field winding configurations are not efficient.

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Peter Taylor:
The three field windings displaced by 1/3 of a revolution of an electronic motor can be configured in the following three ways.
Star (where an end of each winding is connected in common and the other three make four external connections).
This requires that one winding be off in each revolution, giving a power to weight ratio of 2/3 of the maximum.
Delta (where the three windings are connected in series and the junctions give three external connections).
This requires that one winding be off in each revolution, giving a power to weight ratio of 2/3 of the maximum.
Other (where the ends of each winding make six external connections).
This allows three windings to be on at all times, giving a maximum power to weight ratio.
The common consensus in electronic motor control is to use Star or Delta configurations.
The third configuration has a 1/3 higher power to weight ratio.
This article explains why this rarely appears in a google search for 'electronic motor control'.
It is cheaper on a commercial scale to manufacture Star and Delta configurations because they require fewer half h bridges and external copper connections.
The Other configuration requires three full h bridges and six external copper wire connections, and costs more.
In reality, the most efficient design has been hidden by a ruling class who's motivation is greed, not elegance (beauty and simplicity in design).

rob77:

--- Quote from: Peter Taylor on June 13, 2022, 01:49:49 pm ---The three field windings displaced by 1/3 of a revolution of an electronic motor can be configured in the following three ways.
Star (where an end of each winding is connected in common and the other three make four external connections).
This requires that one winding be off in each revolution, giving a power to weight ratio of 2/3 of the maximum.
Delta (where the three windings are connected in series and the junctions give three external connections).
This requires that one winding be off in each revolution, giving a power to weight ratio of 2/3 of the maximum.
Other (where the ends of each winding make six external connections).
This allows three windings to be on at all times, giving a maximum power to weight ratio.
The common consensus in electronic motor control is to use Star or Delta configurations.
The third configuration has a 1/3 higher power to weight ratio.
This article explains why this rarely appears in a google search for 'electronic motor control'.
It is cheaper on a commercial scale to manufacture Star and Delta configurations because they require fewer half h bridges and external copper connections.
The Other configuration requires three full h bridges and six external copper wire connections, and costs more.
In reality, the most efficient design has been hidden by a ruling class who's motivation is greed, not elegance (beauty and simplicity in design).

--- End quote ---

what the actual f**k are you talking about ?  :-// in a 3phase system you never have a "winding OFF" , you have 3 phases 120degrees apart and none of them if "OFF" in any point in time.

Brumby:

--- Quote from: Peter Taylor on June 13, 2022, 01:49:49 pm ---... ... ...
Other (where the ends of each winding make six external connections).
This allows three windings to be on at all times, giving a maximum power to weight ratio.
...
The third configuration has a 1/3 higher power to weight ratio.
... ... ...

--- End quote ---
Fascinating.

Please show your working.

Peter Taylor:
The article mentions a h bridge. Does this imply a switched controller, or a linear one ?
I am not teaching basic theory. You show the reasoning.

Brumby:

--- Quote from: Peter Taylor on June 13, 2022, 02:27:49 pm ---The article ...
--- End quote ---
What article?


--- Quote ---... mentions a h bridge. Does this imply a switched controller, or a linear one ?
--- End quote ---
H bridge topology is not hard to understand.  Try Google.


--- Quote ---I am not teaching basic theory. You show the reasoning.

--- End quote ---
That's "Trolling 101".  Come back when you understand some basics about H bridges, 3 phase and how they relate to motor operation.

Oh ... and don't forget the elephant in the room: Physical construction and all that that entails.

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