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This paper presents an improved Fractional Short Circuit Current (FSCC) Maximum Power Point Tracking (MPPT) technique in which an additional control loop is used to find the proper moment to measure the SCC. The target is to reduce the power losses in MPPT process that occur as a result of intermittent time based short circuit current measurements. The proposed modification enables the conventional FSCC MPPT to decide intelligently about the measurement of SCC thus reduces the number of times the photovoltaic (PV) module is isolated from the load. Although number of algorithms for tracking MPPT has been reported, the proposed method suits well for low cost PV applications. A Matlab/Simulink based model is employed to test the functional abilities of the proposed method. The comparison of the proposed method and conventional time based FSCC method is also presented in the simulation analysis. Finally, a 130W prototype based on the dSPACE DS1104 controller and experimental results are presented to verify the effectiveness of the proposed method. The technique is verified under uniform shading conditions. The results show satisfactory performance against test conditions. [ABSTRACT FROM AUTHOR]

Cost of the photovoltaic (PV) systems and their peripherals has been always an issue when considering them for various applications. Using an inexpensive maximum power point tracking (MPPT) system is a simple but efficient solution to reduce the cost of the PV systems and increase the public acceptance. This paper presents the simulation and hardware implementation of incremental conductance algorithm using buck-boost converter and PIC18F4520 controller. Design and simulation of the proposed system are presented using matlab and simulink tools. The proposed system is also tested on KC85T PV module for constant and changing weather conditions. Experimental results indicated the capability and functionality of the proposed system on tracking maximum power point with the voltage ripple ratio = 0.006, which is near to the ideal mathematically calculated assessment. The proposed MPPT system helps to reduce the complexity and cost of the PV systems and also ensures the largest operating region of the PV module. [ABSTRACT FROM AUTHOR]

The efficiency of the fuel cell system nonlinearly depends on operating conditions and the air flow supplied to the fuel cell system is one of the most significant factors in determining the efficiency. The conventional method of controlling the air flow is to stabilize the oxygen supply at a predetermined constant rate for the optimal efficiency. However, in practice, the optimal point can deviate from the pre-set value due to the varying operating conditions, such as the uncontrollable load. Therefore, the maximum efficiency point tracking (MEPT) controller is necessary to maintain the optimal efficiency over a broad range of operating conditions. In this paper, the MEPT controller is designed based on the extremum seeking control algorithm for searching the optimal oxygen excess ratio in real time to maximize the efficiency of the fuel cell system. Simulation was conducted in the matlab/simulink environment and the results demonstrate that the proposed control method is able to track the maximum efficiency point when variations in operating conditions occur. [ABSTRACT FROM AUTHOR]