Maximum torque high efficiency microprocessor based control of induction motors

In the paper a novel method for maximum torque and high efficiency control of induction motors is suggested. It is based on the condition that in every moment, for every speed the torque should be maximum or at least near the maximal value. This is achieved by calculation of the optimal frequency of the supply voltage, which is function of the rotation speed n in the moment and the parameters of the motor. The calculations can be done in advance, off-line, for a sufficient number of n and the results are introduced into the memory of the on-line controller. Another fast method for calculation of suboptimal values of the frequency which can be applied on-line is suggested and proven with theorem. The analysis made in the paper shows that as a result the efficiency can also increase. The flow-chart of the control algorithm is shown.