Analysis and Experimentation of Soft Switched Interleaved Boost Converter for Photovoltaic Applications

Conventional energy sources are fast depleting due to poor conservation practises and excessive usage while the world’s energy demands are growing by minute. Additionally, the cost of producing conventional energy is rising also leading to an increase in harmful environmental pollution. Hence, there is a need to look at alternative energy sources such as sun, water and wind. Photovoltaic (PV) is a very promising option as it uses energy from naturally available sunlight distributed throughout the Earth which is not only pollution free but also abundant and recyclable in nature.Among the different DC-DC converters proposed in literature, interleaved boost converter is best suited for PV and other high power density applications.Conventional interleaved boost converters experience switching losses and switching stresses during turn-on and turn-off periods due to hard switching.  In order to eliminate the power loss in the converter devices, soft switched Interleaved Boost Converter (IBC)  is proposed in this paper.  Soft switching is achieved with the use of an LC resonant tank circuit. The tank circuit is responsible for Zero Voltage Switching (ZVS) and Zero Current Switching (ZCS), eliminating the power loss in the switches appreciably. Since photovoltaic source is used as the input to the converter, a Maximum Power Point Tracking (MPPT) algorithm is implemented to extract maximum available power from the PV panel. Furthermore, the device losses, ripple and current sharing based on input and output characteristics are recorded and examined. Simulation study of the design is carried out using MATLAB/SIMULINK software. A hardware prototype with PV module is developed to validate the simulation results.