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Special Feature
Newsletter "SEI WORLD" Vol. 451

Solar Cell-String Monitoring & Analysis System by PLC (SSMAPR)

What is the Solar Cell-String Monitoring & Analysis System by PLC? (SSMAP™)

String monitoring terminal and current sensor
String monitoring terminal and current sensor

The Solar Cell-String Monitoring & Analysis System by PLC (SSMAP™) developed by our company is a system that monitors in real time the amount of electricity generated per string*1 from a mega solar power generation system.

Monitoring terminals are installed in connection boxes*2 to measure each string’s current and voltage. A data collection device installed near the power conditioner collects data and compares relative data per string to achieve early detection of problems and to minimize loss of income from selling electricity.

While many mega solar power generation systems are recently constructed, early failure after installation of a large number of solar panels, their long-term performance degradation and failure caused by external factors will decrease the amount of power generated and electricity sold. Since a mega solar power generation system comprises tens to hundreds of thousands of solar panels, it is very difficult to detect which solar panels are deteriorating by the total amount of generated electricity alone. This is why this product is highly evaluated as an inexpensive monitoring system that can be easily installed to monitor and adjust the amount of electricity generated per string in real time.

*1
A string is a minimum unit of solar panels connected in series.
*2
A connection box is a device that collects the electricity generated by solar panels and provides the electricity to the power conditioner.

Features of SSMAP™

For many years, we have developed the PLC (Power Line Communication) technology that enables data transmission via power lines, and we applied the PLC technology to this product using high-voltage (from 600 V to 1 KV or higher) direct current (DC) transmission cables installed in mega solar power generation systems as communication media.

Although the basic principle of the PLC is well known in the ITC field, we are the first to successfully commercialize this technology for environments in which high-voltage DC is applied and large noise is produced, such as in mega solar power generation systems.

This product utilizing this PLC technology has the following three features:

1.Dedicated communication lines are unnecessary.

The PLC technology eliminates the need for installing dedicated communication lines because it uses power lines for data communication.

2.Excellent noise and lightning surge resistance

Our long-time accumulated PLC skills enable the construction of reliable systems that are extremely resistant to noise and temporary excessive rises in voltage and current caused by lightning (lightning surges).

3.Easy retrofitting to existing mega solar power generation systems

Its compact size and clamp-type sensors enable installation in existing mega solar power generation systems.

Installation example of a string monitoring terminal
Installation example of a string monitoring terminal

Comparison of power generation monitoring systems for mega solar power generation systems

Track record of adoption

Several mega solar power plants around Japan have decided to adopt our SSMAP™, highly evaluating the features such as not needing dedicated lines that enables economic efficiency, and excellent noise and lightning surge resistance that enables construction of reliable systems. We will make our product’s features more known to customers and boost sales.

■Mitagawa Solar Power Plant

Saga Prefecture, Max. output: 1 MW, Operator: Sumitomo Mitsui Construction Co., Ltd.

■Matsuzaka Yamamuro Mega Solar Power Plant

Mie Prefecture, Max. output: 13 MW, Operator: Sanko Real Estate Co., Ltd.

■Vitec Isaribi-kan Iwate Prefecture Takizawa City Solar Power Plant

Iwate Prefecture, Max. output: 15 MW, Operator: Vitec Co., Ltd.


More information on this product can be found at:
Web site for the Solar Cell-String Monitoring & Analysis System by PLC (in Japanese):http://www.sei.co.jp/string/
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