抄録
This paper investigates the influence of MPPT control method in the PCS on the occurrence of reverse voltage in PV modules. When the power of modules in part of a PV array declines, a situation arises in which those modules must be replaced with modules of different rated value. In such a case, the difference in the characteristics of existing modules and replacement modules may cause the occurrence of reverse voltage by MPPT control of the PCS in the replacement modules, which may cause heat and ignition. Although protection devices are connected to protect the modules from the occurrence of reverse voltage, they may not work. Therefore, it is indispensable to clarify the range of safe combinations of modules of different rated value. First, an MPPT control algorithm of three kinds of PCSs is implemented. To validate the developed control algorithm the simulated operating voltage is compared with measured one. Second, in order to clarify the conditions under which reverse voltage is likely to occur, the influence of the MPPT operation, open circuit voltage and short circuit current of PV modules and the pattern of connection of existing and replacement modules in a PV array on the occurrence of reverse voltage is investigated.
