Evaluation of remote diagnoses performance by using Operating Performance Index at different measurement intervals for residential PV systems

摘要

Output power of a residential PV system is reduced by many factors such as shading, a malfunction, and a breakdown. A remote diagnoses method for residential PV systems by using Operating Performance Index (OPI) is developed in this research. OPI is defined as measured power generation divided by estimated power generation. In order to vilify the effect of time resolution on accuracy of OPI calculation, OPI(t) was calculated in the following measurement intervals: 1, 5, 10, 30, and 60 min. We also divided the celestial sphere into the following azimuth ψ [deg.] and solar height h [deg.] resolutions: ψ = 5, 10, 15, and 20, h =5, 10, and 15. OPI_m(ψ,h) is the OPI(t) frequency value of each sector of ψ and h. OPI_(Mp) is the mode value of OPI_m(ψ,h) and it shows power generation performance of the system. We have evaluated OPI at different measurement intervals with various celestial sphere resolutions.