OPTIMIZER, PHOTOVOLTAIC POWER GENERATION SYSTEM, AND I-V CURVE SCANNING METHOD FOR PHOTOVOLTAIC ASSEMBLY

摘要

An optimizer, a photovoltaic power generation system, and an I-V curve scanning method for a photovoltaic assembly. The photovoltaic power generation system (1000) comprises multiple photovoltaic assemblies (300), multiple optimizers (100), and an inverter (500). Each of the optimizers has an input terminal connected to at least one of the photovoltaic assemblies, and output terminals of the multiple optimizers are connected in series to form an assembly string, which is then connected to the inverter. The optimizers comprise a conversion unit (10) and a control unit (20) used to control the conversion unit. The optimizers further comprise an auxiliary power supply (30), an energy storage unit (40), and a first unidirectionally conductive unit (50) which are connected between the conversion unit and the control unit. The control unit performs I-V curve scanning respectively for each voltage interval, wherein the voltage intervals are obtained by segmenting output voltages of the photovoltaic assemblies corresponding to the optimizers, said voltages ranging from an open-circuit voltage to a pre-determined minimum voltage, and the number of the voltage intervals is at least two. The photovoltaic power generation system is capable of reducing the cost and volume of the optimizers.