Abstract:
a PV energy system. The PV system shows nonlinear power voltage (P–V) and current voltage (I–V) characteristics. There is single peak in the P-V characteristics of a PV module under uniform irradiance which is called the maximum power point (MPP). The temperature and irradiance of the environment are responsible for the change in the P-V and I-V characteristics of a PV module; which changes the MPP. The backbone of the research on the PV system is to track this MPP under changing temperature and irradiance. A maximum power point (MPP) tracking control system with a suitable DC/DC converter is used to track the MPP of a PV module continuously under changing environment conditions as well as change in the connected associated load. Power electronics provides the DC/DC converter to follow the maximum power transfer theorem and transforms the load impedance to source side such that to have operating point (OP) at MPP continuously. Partial shading and module mismatch are the scenarios which creates multiple peaks in P-V characteristics curve of a PV module. The highest peak out of all peaks is called global MPP while all remaining peaks are called local peaks. The conventional algorithms could not track this global MPP which demands a better MPP tracking algorithm to track the global MPP. This manuscript discusses some novel global MPP tracking techniques. The selection of suitable DC/DC converter is very important to track the MPP in uniform irradiance and global MPP in case of partial shading. Selecting a wrong DC/DC converter topology can cause sub optimal operation and complete loss of trackability. Detailed analysis of five basic non isolated DC/DC converters with respect to their operating area and tracking ability for MPP has been undertaken. Influence of different resistive loads on each topology been also discussed thoroughly. The observations discovered that the sepic DC/DC converter is the best topology to track the MPP and harvest the maximum energy from a PV system.
