Loads - Note 1
MOTOR EFFICIENCY DISSECTED ANALYSIS 1.) Law of Conservation of Energy (ideal): W,in = W,out 2.) First Law of Thermodynamics (practical): Q = W + dU Total energy = Work done + change in Internal energy W,in = W,out + W,losses W,in > W,out Energy input is always greater than energy output because of energy losses. 3.) Utilizing energy through time: (W,in / t) = (W,out / t) + (W,losses / t) 4.) Power and energy relationship: P = W / t P,in = W,in / t P,out = W,out / t P,losses = W,losses / t 5.) Power flow equation: P,in = P,out + P,losses P,in > P,out Power input is always greater than power output because of power losses. 6.) Usable power and energy: efficiency = (P,out / P,in) * 100 efficiency = (W,out / W,in) * 100 SUMMARY Motor efficiency is all about how well a motor converts energy input into energy output, given imperfections like friction and waste heat.