The low-cost single-stage grid connected photovoltaic system with a modified MPPT method

Single-stage topology and the maximum power point tracking (MPPT) algorithm have advantages such as simple configuration and high efficiency in grid-connected photovoltaic (PV) systems. However, in conventional systems, current and voltage sensors of PV system are normally used for MPPT. This paper presents a low-cost single-stage grid- connected PV system without PV current sensor with a modified MPPT method. This method is not derived from complex state equations and is not dependent on any circuit parameters. It simply calculates the output power of the inverter to replace the input power of the PV systems in the MPPT algorithm. The new algorithm is simulated by using Matlab/Simulink software and implemented in the experimental prototype. With the one-stage configuration and PV current sensorless method, the prototype is suitable for lowcost implementation in the practice.