10 March 2022

Sumitomo Electric Releases a PLC String Monitoring Unit for Solar Power Plants Compatible with High-Output Panels — Capable of measuring up to 20 strings with a maximum current of 20 A each at the same time —

Sumitomo Electric Industries, Ltd. is pleased to announce the release of a power line communication (PLC) string*1,2 monitoring unit for solar power plants equipped with high-output panels. This unit can monitor up to 20 strings with a maximum current of 20 A each. The Company is now accepting orders for shipment in early FY2022.

In order to reduce the construction and operational costs of solar power plants, the voltage of solar panels has been increasing from 1,000 V, which was previously dominant, to 1,500 V, and the current value per string has also been increasing. Against this backdrop, Sumitomo Electric has enhanced the functionality of its PLC string monitoring unit, which detects failures in solar panels, enabling it to measure currents of up to 20 A per string for the first time in Japan (based on our research). Despite the significant increase in measurable string current, the unit size remains the same, making installation easy.

To contribute to stable operation and high maintenance efficiency of solar power plants, which have been increasingly constructed to realize carbon neutrality, Sumitomo Electric will continue to offer highly convenient PLC string monitoring units and auxiliary services.

Main features of this product

1. Compatible with a 20 A string current at power plants of 1,500 VDC designs
2. Compatible with combiner boxes*3 of various designs up to 20 strings
3. PLC (power line communication) technology used for transmission of string data
  • ● Significantly reducing the construction period and costs of solar power plants because construction of communication lines is not required
  • ● No potential difference in the unit in the event of lightning damage because no communication line is required, achieving lightning protection characteristics higher than those of the RS-485 communication method
  • ● Achieving data communication more stable than other communication methods (RS-485, radio) thanks to Sumitomo Electric’s unique noise resistance performance
4. AI-based analysis of the data, which is obtained by the string monitoring unit, on the cloud to send a daily email in the event of a fault and offer a diagnosis service (optional)
5. More than 10,000 units shipped to solar power plants in Japan

*1 Power line communication (PLC): A technology designed to use a power line as a communication channel. Sumitomo Electric’s PLC products use low-frequency PLC technology at frequencies not higher than 450 kHz. String current measurement data signals are added to a DC line.
*2 String: A minimum configuration unit of series-connected solar panels.
*3 Combiner box: A device to bring together wiring from multiple strings and connect to a power conditioner.


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