Sumitomo Announces PLC Technology for String Monitoring at Solar Plant

2014/03/14 00:38
Shinichi Kato, Nikkei BP CleanTech Institute
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Sumitomo Electric Industries Ltd commercialized a system that uses power transmission cables being used to transmit 600V-1kV or higher-voltage direct-current electricity at a mega-solar (large-scale solar) power plant as data transmission cables to monitor the operation of the plant.

This was announced March 12, 2014. Power line communication (PLC), which uses power transmission cables as communication cables, has already been employed in, for example, the field of information and telecommunications. However, to use PLC for a 1MW or higher-capacity large-scale solar power generation system, it is necessary to deal with high-voltage direct-current electricity and noise.

This time, Sumitomo Electric developed a PLC technology that enables to use power transmission cables being used for 600V-1kV or higher-voltage direct-current electricity and ensure a high information transmission accuracy even in an environment where large-capacity PV inverters for mega-solar plants generate a large amount of noise. With the technology, data is transmitted by using a frequency band of 10k-450kHz. The technology was verified with help from Yurtec Co Inc (Sendai City, Miyagi Prefecture).

The new PLC technology uses power transmission cables that connect connecting boxes used to collect electricity from each string (of 11-19 solar panels connected in series) and PV inverters. It is used for "string monitoring," which monitors the amount of electricity being generated in each string in real time. String monitoring makes it easy to find solar panels whose output performances have been drastically lowered due to failures, etc.

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