Hitachi, Ltd.

Koki Morikawa

Tomoharu Nakamura

Toru Kouno

Yuuichi Nagayama

Satoshi Miyazaki

Akihiro Nakamura

Tohru Kohno

Masaaki Fujimori

Tetsuharu Ohya

A failure diagnosis system is configured to calculate an estimated irradiation on a first photovoltaic string and an estimated operating temperature of the first photovoltaic string based on a short-circuit current and an open-circuit voltage on a current-voltage characteristic of the first photovoltaic string, and the array output voltage value and the array output current value measured by an array measurement apparatus. The failure diagnosis system is configured to calculate an estimated current value of the first photovoltaic string based on the estimated irradiation, the estimated operating temperature, and the current-voltage characteristic. The failure diagnosis system is configured to diagnose degradation of the first photovoltaic string by comparing the measured current value of the first photovoltaic string and the estimated current value.

Failure diagnosis method and failure diagnosis system for photovoltaic system

A power generating system comprising: a plurality of power generating units coupled in parallel; a power collecting device for collecting electric power output from the plurality of power generating units; and wirings for coupling the plurality of power generating units and the power collecting device. A ratio of a conductor diameter to a predetermined length of each of the wirings is defined as a reference ratio. A value obtained by multiplying the reference ratio, a number of the wirings, and a loss generated by a specific wiring together is subtracted from a value obtained by multiplying a predetermined number of wirings for adjustment by a ratio of a conductor diameter to a length of the specific wiring. A total of the ratios of the conductor diameters to the lengths of the predetermined number of the wirings for adjustment is determined as a value less than the subtracted value.

Power generating system and method of designing power generating system

A low-cost failure diagnosis method, without addition of a measuring unit and a communication unit, provided for a solar battery system, of calculating a working temperature and the number of failed solar battery modules in a solar battery array, by calculating a solar radiation amount while updating a predetermined coefficient as a ratio between a short-circuit current and a working current in accordance with state of the solar battery array and using measured data having the working current and working voltage measured with a detection unit.

Failure diagnosis method for photovoltaic power generation system

Growing community of inventors

Tokyo, Japan

Koki Morikawa