Department of Electrical Engineering, Faculty of Engineering, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran
This paper describes a new design for direct sliding mode method with a high switching frequency using the PD-PI type sliding surface applied to a negative output Luo converter worked in continuous current mode for applications required constant power source such as aerospace applications, medical equipment and etc. Because of the output power and line changes, the converter model is also nonlinear and time varying. In addition, losses dissipation and voltage drops caused a deviation between the theoretical and actual output voltage of this converter. For improvement of the converter performance along with the current and voltage regulations, a nonlinear controller is required. This suggested controller is proper to inherently variable structure of the converter and can cope with nonlinearities associated with its model. The goal is to ensure a satisfactory response for the converter. The practical results showed that the proposed strategy helps to eliminate the voltage error along with continuous current operation of the converter in very light loads and high switching frequency in different operating points.