Taiyo Yuden Co., Ltd. has announced the development and commercialization of a wireless string monitoring system for industrial solar power plants. This is a system for measuring and monitoring the status of power generation in each string, and is configured by a management unit, which is the base unit, and string sensor units, which are terminal units. The management units can connect to up to 350 string sensor units and have a maximum power consumption of 2W. The string sensor units are rated for a maximum voltage of 1,000Vdc and can detect currents from 0.5A up to 12A with 2% accuracy. Power consumption of the string sensor units is a maximum of 0.5W. Both wireless units operate in the 2.4GHz band.
This system detects both the current flow through each string and the voltage of the installed solar panels. If there is a decline in output due to the failure of a panel or an improper wiring connection, it is possible to identify the string in which the problem has occurred. Taiyo Yuden has also been able to construct a wireless sensor network by combining together their power supply circuit technology and wireless module technology. This wireless communication solution is performed by using only a slight amount of power generated by solar panels, and Taiyo Yuden has eliminated the need for batteries and related wiring installations which results in a significant cost savings.
Taiyo Yuden has conducted several successful demonstration experiments at solar power plants and plans to commence production at their subsidiary Akagi Electronics Co., Ltd. (Takasaki City, Gunma Prefecture, Japan) from August 2014.
Tens of thousands of solar panels are installed in large-scale solar power plants and mega solar power plants. If a single solar panel develops a fault, the output of the entire string drops, resulting in a loss of power generation for the entire power plant. Although the use of a power conditioner for power monitoring provides an understanding of the status of power generation of the entire power plant, the details of the failure and the location of occurrence of the problem cannot be detected without expending a large amount of effort and costs to identify the problem.
To resolve this issue, Taiyo Yuden has used its innovative technical expertise and has combined its power supply circuit technology and wireless module technology, and commercialized a wireless string monitoring system. By installing a sensor unit in each string, a huge number of panels can be monitored on a string-by-string basis.
The wireless module helps realize power saving through the multi-hop communication function. By combining the wireless module with our power supply circuit technology, the wireless module can be operated by using only a slight amount of power generated by the solar panels. The result from this solution is the elimination of the need for both power supply cables and communication cables. This system can be installed on a later stage without performing additional processing in already-installed solar panels and rental panels and offers a significant reduction in construction cost.