Exponential Approaching Sliding Mode Control of PWM DC/DC Converters

Some difficulties occur in the control of DC-DC convertors because of the inherent nonlinearity and time variation. A sliding mode control scheme based on exponential approaching regulation was designed in this paper for PWM DC/DC converters. The approaching speed varies from big value to zero, which not only shortens the approaching time, but also decreases the rate of moving state around the switching surface. Simulation results show that the converter behavior, not only the response speed and the steady state error, but also the overshoot, are improved obviously, and the chattering caused by conventional sliding mode control can be eliminated effectively.