Optimal control of electric drive with simultaneous control inputs for motor current and flux
Abstract
A detailed mathematical analysis of the optimal control of a dc electric drive with a variable magnetic flux is presented. Expressions are found for the optimal controller. When this controller uses real time microprocessors control hardware, formulas are also derived for the various portions of the optimal process as well as the logic expressions for the switching of these parts of the process. The resulting optimal process differs from previous determinations in that the braking portion, when a resistance moment is present, contains a free rundown (passive braking) region, before and after which there can be regions of active braking, when the motor produces an electromagnetic moment. In one numerical example of step dc motor control, which is used to compare the optimal process found here with one developed earlier, power losses are found to be reduced by 5.44% with the new process. The entire solution of the problem using the procedure presented here reduces to finding the conditional extremum of some function of several variables whose number is no greater than the dimensionality of the system and does not lead to a boundary value problem.
 Publication:

USSR Rept Eng Equipment JPRS UEQ
 Pub Date:
 August 1984
 Bibcode:
 1984RpEE........28P
 Keywords:

 Algorithms;
 Efficiency;
 Electric Motors;
 Microprocessors;
 Numerical Control;
 Optimal Control;
 Braking;
 Energy Dissipation;
 Magnetic Flux;
 Mathematical Models;
 Power Efficiency;
 Electronics and Electrical Engineering