Chattering Reduction Using Improved Switching Functions in the SMC Method for Battery Chargers of PMDs

This paper proposes a chattering reduction using improved switching functions in the sliding mode control (SMC) method for battery chargers of personal mobility devices (PMDs). The battery charger of PMDs requires a controller to convert various voltage levels. The PI controller is commonly used, however, tuning the gain is necessary to improve responsiveness, which can result in overshoot. The SMC method has robust characteristics, being resilient to disturbances and ensuring stability without causing overshoot compared a PI controller. The switching function is important in the main operations of the SMC. The gain and type of the switching function can significantly influence the response at which the control variable converges to the origin. In addition, the occurrence of chattering, which can adversely affect the lifespan and stability of battery charger of PMDs. Therefore, this paper compares different switching functions used in the SMC method and identify the most suitable switching function for battery charger of PMDs. The validity of chattering reduction using improved switching functions in the SMC method for battery chargers of PMDs is verified by the simulation and experimental results.