Current control strategy for brushless DC motors based on a commonDC signal

摘要

A simplified current controlled modulation technique for brushlessnDC motors is presented. It is based on the generation of quasinsquare-wave currents, using only one current controller for the threenphases. The advantages of this strategy are: (a) very simple controlnscheme; (b) the phase currents are kept balanced; (c) the difficultnsensing of DC link current in flat plates is avoided; and (d) thencurrent is controlled through only one DC component. Thesencharacteristics allow to use the triangular carrier as a current controlnstrategy for the power transistors, which is simpler and better thannother options. Computer simulations using power electronic simulatorn(PSIM), have been developed to show the good characteristics of thisnsolution, and its simplicity. Some experiments with a 15 kWnmotor-inverter system, show the excellent behavior under steady-state,nand transient situations, such as step response and reversal of power