This paper presents a new maximum power point tracking (MPPT) method for photovoltaic (PV) systems. The proposed method improves the working of the conventional perturb and observe (P&O) method in changing environmental conditions by using the fractional short-circuit current (FSCC) method. It takes the initial operating point of a PV system by using the short-circuit current method and later shifts to the conventional P&O technique. The advantage of having this two-stage algorithm is rapid tracking under changing environmental conditions. In addition, this scheme offers low-power oscillations around MPP and, therefore, more power harvesting compared with the common P&O method. The proposed MPPT decides intelligently about the moment of measuring short-circuit current and is, therefore, an irradiance sensorless scheme. The proposed method is validated with computer software simulation followed by a dSPACE DS1104-based experimental setup. A buck-boost dc-dc converter is used for simulation and experimental confirmation. Furthermore, the reliability of the proposed method is also calculated. The results show that the proposed MPPT technique works satisfactorily under given environmental scenarios.

This paper presents a grid-connected photovoltaic (PV) flyback inverter operating in discontinuous conduction mode (DCM) and controlled through an efficient, reliable, and cost-effective hybrid maximum power point tracking (MPPT) method. Although the proposed method can be applied to any grid connected inverter topology, in this paper, it is applied on a modified flyback inverter (MFBI) topology. Moreover, the proposed MPPT method is a two stage scheme and hence, a hybrid solution, as it consists of a combination of fractional short circuit current (FSCC) and hill climbing (Perturb and Observe (P&O)) method reformulated. The change in weather condition is accurately detected using the current limit technique such that the difference in short circuit current and photovoltaic current is monitored continuously. It is demonstrated that the use of current limit enables the system to swiftly track the maximum power point (MPP) in abruptly changing environmental conditions. The proposed MPPT method needs only two sensors for current and voltage measurement and is, therefore, cost effective and reliable. The system is tested through simulations and real-time setup using dSPACE DS1104. The results prove the effectiveness of the proposed hybrid MPPT compared with the P&O method under uniform and dynamic weather conditions.

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 130 W 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.