Improved power distribution method for BLDC motor driving power inverters

Temperature requirements of electronic control units used in automotive applications are constantly getting higher. This paper presents a simple driving strategy for the switching elements of BLDC (Brushless DC) motor control electronic unit which enables a better power consumption distribution between them, thus reducing the temperature peaks in the electronic equipment which limits its performance and lifetime. The driving strategy consists in alternating the freewheeling path between low and high-side for each consecutive PWM (Pulse Width Modulation) period. Therefore actively involving in the control of the motor all four switching elements of the bridge during one commutation period, in contrast to the classical low-side freewheeling method which uses only two or three (active freewheeling) switching elements.