— In this paper, we proposed a new mathematical model of the I-V characteristic of a faulty photovoltaic generator. It presents its behavior in normal and faulty operations. In particular, when its basic components such as cells, bypass and blocking diodes are subjected to the impedance or reversed polarity faults. The developed model of the faulty PV generator will allow studying of the I-V characteristic, measures the tolerances of the technical functions, avoids numerous experiments, and ensure better assessment of fault consequences. NOMENCLATURE I ph = Photocurrent standard condition. I 0 = Reverse saturation current of the diode. Z = Electrical impedance R S = Cell series resistance. nc: ncg / ncp = Cell number: good / defective. ng: ngg / ngp = Group number: good / defective. nm: nmg / nmp = Module number: good / defective. ns: nsg / nsp = String number: good / defective. nfg / nfp = Good / defective generator. N Cells = Number of cells in each group. N Groups = Number of groups in each module. N Modules = Number of modules in each string. N Strings = Number of strings in each generator. V / I = Voltage / current. P = Power. I Bypass_Diode = Bypass diode current. V Cell_Imposed = Voltage imposed. a = Diode ideality factor. V t = Diode Thermal voltage.