Analysis of Sliding-Mode-Controlled Boost Converters with Mixed Loads

This paper analyzes sliding-mode-controlled boost converters supplying a mix of resistive and constant power loads. The conventional sliding-mode control applied to the mixed load system is first analyzed: the hitting and existence conditions are examined and a closed-loop small-signal model is developed. The stability condition is established in terms of the sliding coefficient and load composition. By exploiting the stability condition, a new adaptive sliding-mode controller featuring an adjustable sliding coefficient and a load estimation technique is proposed. The proposed control exhibits faster dynamic response and improved stability compared with the conventional approach. Simulation studies and experimental results using real-time hardware-in-the-loop simulator validate the effectiveness of the proposed control.