Dependence of String Power on its Height in the Array in Yoshinogari Mega Solar Power Plant

In order to make MPPT control of PCS effective, strings of almost same maximum power should be connected in parallel to the PCS. We have collected a big data of string powers measured in Yoshinogari mega solar power plant (MSPP) in Japan for two years. The data shows that string powers depend on height in the array. The average power of strings at the highest position in the array was greater approximately 7 than strings at the lowest positon. Several causes of this dependence are analyzed quantitatively.