Power conditioner, photovoltaic system and abnormality determination method

• Main Authors: MASAO MABUCHI, TAKUYA NAKAI, YASUHIRO TSUBOTA, KOTARO NAKAMURA
• Format: Patent
• Language: Chinese; English
• Published: 06.08.2014
• Subjects: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC,OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWERSUPPLY SYSTEMS; CONTROL OR REGULATION THEREOF; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION; GENERATION OF ELECTRIC POWER BY CONVERSION OF INFRA-REDRADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, E.G. USINGPHOTOVOLTAIC [PV] MODULES; MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; TESTING

The invention relates to a power conditioner, a photovoltaic system and an abnormality determination method. In a case that a plurality of photovoltaic strings differ from one another in electric power generation such the case that the number of photovoltaic modules constituting each of the plurality of photovoltaic strings varies, an open-circuit voltage of each of the plurality of photovoltaic strings cannot exactly be detected by measuring the voltage at the parallel connection point. An open-circuit voltage value acquisition unit acquires a first open-circuit voltage value of a first power supply, when a first switch is in an off period while a potential controller performs control such that a voltage at a first backflow prevention circuit on a side opposite to the first power supply is greater than or equal to a voltage at the first backflow prevention circuit on the side of the first power supply. A power supply abnormality determination unit determines whether the first power supply has an abnormality