Chorus Technology


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Conventional 3 Phase Motor

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This picture shows 3 rotating sets, which are graphical representations of stator conductor currents. 

Middle Set: The middle picture is the fundamental. This is what a pure sine wave looks like in a motor which has 2 poles; the north and south pole rotate around the middle. This field does not show any harmonic content. It rotates at a constant speed. 

Right Set: The right picture shows the 5th harmonic. Note that it spins in the opposite direction, and at 5 times the speed, of the  fundamental. In this picture, it is a braking torque. 

Left Set: The left picture shows what happens in the motor when the fundamental and the 5th harmonic are both flowing. The braking torque appears as a variation in fundamental speed and magnitude. All the elements of the set do not move together. This greatly harms efficiency, and increases heating. 

 


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The sets in this picture are the Chorus equivalent, showing the 5th harmonic. 

Middle Set: The middle, showing the fundamental, is unchanged from the 3 phase version. 

Right Set: The right, on the other hand, has been altered because of the features unique to Chorus (see the tutorial document). The 5th harmonic no longer rotates in the opposite direction of the fundamental. Instead, it moves in the same direction, and at the same speed. Note, too, that there are 10  "bumps" on the ring. Each pair of bumps represents a pair of poles. So the 5th harmonic here, as described in the Tutorial, is acting as a 10 pole field, rotating in the same direction and at the same speed as the fundamental. 

Left Set: The left picture shows the combination of the 5th harmonic and the fundamental in a Chorus machine. The shape is different than the pure fundamental, but all the elements of the set move together. The 5th harmonic, which had previously been a braking torque, becomes a boosting torque. This increases the output of the motor, while increasing efficiency.

Note that the concept shown here has been proven. The Chorus was run with only 5th harmonic content, and the rotor spun at the same speed as the fundamental, with a substantial torque. Full data is available in the file: pure_fif.xls.zip. Animation is provided for demonstration purposes, and it is not necessarily to scale. 

 
 
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