New Industry Products

PLC String Monitoring Unit for 1,500Vdc Solar Power Plants

April 17, 2018 by Paul Shepard

Sumitomo Electric Industries, Ltd. is now open for orders for a power line communication (PLC) string monitoring unit it has developed for 1,500Vdc solar power plants. This monitoring unit is scheduled to begin shipping in July 2018 to solar power plants in Japan and abroad.

Under the feed-in tariff (FIT) for renewable energy, the price for generated electricity has recently been decreasing. Against this backdrop, an increasing number of solar power plant construction projects have been designed at 1,500Vdc to reduce the installation cost.

Compared with the previously dominant 1,000Vdc designs, 1,500Vdc designs reduce component and member quantity required and promises a lower installation cost through the use of more panels per string.

In line with this trend, Sumitomo Electric has developed a PLC string monitoring unit compatible with 1,500Vdc, in addition to the previous product tailored for 1,000V designs. This product monitors each string to determine whether the solar power plant is operating properly and detects faults. The slave units of the product monitor strings, while the master unit collects data, with the communication between them being based on Sumitomo Electric's superior PLC technology.

Advantages of this configuration include:

  • Use of an existing power line for communication eliminates the need for additional installation of a communication line, reducing the overall cost and
  • The wired system ensures stable communications. Consequently, this product enables the construction of 1,500Vdc solar power plants equipped with monitoring functions at a more reasonable cost.

Additionally, Sumitomo Electric plans to make this product compliant with International Electrotechnical Commission (IEC) standards for use at solar power plants in IEC member countries.

Product features include:

  • Compatible with 1,500Vdc power plants
  • Installable in various combiner boxes due to versatile design (two vertically stacked or separately installed boards)
  • Covers up to 20 strings and is suitable at sites with various string designs
  • Stable data communication due to PLC, which is specifically highly lightning resistant, and Sumitomo Electric's proprietary noise immunity design
  • Compliance with IEC standards planned for use in IEC member countries