A sliding mode current control scheme for PWM brushless DC motor drives

This paper proposes a sliding mode current control scheme for pulsewidth mo dulation (PWM) brushless de motor drives. An improved "equivalent control" method is used in this scheme. A simple algorithm is proposed that differs from the original equivalent control method, which requires extensive calcu lation to estimate the load parameters. This algorithm can be implemented u sing logic circuits. Moreover, using autotuning, the proposed algorithm can be applied without load information. An operating principle for the power stage switching devices called single-side firing is also proposed. Single- side firing solves the dead-time problem, allowing the PWM frequency to be increased and the sampling rate to be raised. This paper explains the curre nt control algorithm, single-side firing principle, and implementation of t he proposed scheme in detail. Simulations and experimental results are give n to show the validity of this scheme.