Efficiency Control Mode

To prove the algorithm works suppose we have a motor which is:

190kv

At the present moment the motor is turning:

1000rpm

We can calculate the voltage the motor is generating (back emf voltage) from:

1000rpm / 190kv = 5.26v bemf

Suppose I am accelerating and want instantaneous 85% electrical to mechanical conversion efficiency, what voltage should I apply to the motor?

5.26v bemf / 85% = 6.18v pwm effective voltage

What is the motor current (assume motor is 0.05ohm)?

(6.18v - 5.26v) / 0.05 = 18.4a motor current

What is the electrical wattage?

6.18v * 18.4a = 113.71w

What is the torque?

60 / (2 * pi * 190 kv) = 0.0502nm/a

0.0502nm/a * 18.4a = 0.9236 newton meters

What is the mechanical power?

1000rpm * ((2 * pi)/60)= 104.71 radians per second

104.71 rad/sec * 0.9236 newton meters = 96.71 watts mechanical

What is the conversion efficiency?

96.71w mechanical / 113.71w electrical = 85%

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