Solar energy yields in real time

• Envalue GmbH installs and operates solar parks for investors and has numerous references throughout Europe.
• The most diverse range of operating conditions need to be continuously measured in order to respond quickly to any malfunctions.
• Envalue uses a system solution from Phoenix Contact to record and transfer the data from the solar park.
• The industrial quality of its components ensures maximum reliability and profitable maintenance in the event of a system failure.

The measuring chain starts with the strings: either 16 or 24 strings are merged and individually saved in the string combiner box (SCB). One double string each is routed through one of the SOLARCHECK module openings in order to record the string currents. Likewise, the voltage and ambient temperature can also be recorded with the SOLARCHECK measuring module. The analog data is processed in a measuring module, digitized, and then sent on via Modbus protocol.

VALVETRAB surge protection for the DC area and PLUGTRAB for securing the communication line, a Uno power supply and connection technology from Phoenix Contact round off the range of SCB equipment used. The collected DC current is transmitted to the inverter via an isolator. The data from all SCBs and inverters and data from the substation's network connection point converge in the data logger cabinet. Installed there as a core component is an ILC 191 Inline controller, which is used to run the photovoltaic management application that was programmed from the Solarworx library's function blocks.

Rüdiger Haslinger, Project Manager at Envalue, explains, “The function blocks from the Solarworx library let you read the data from all commercially available inverters, which has simplified our programming. The support offered by the Phoenix Contact team is also excellent when it comes to connection.” One particular challenge is connection to the control system of direct sellers. But even this is possible without substantial programming effort.

A Smartblue perspective

The complete system overview, which comprises regularly updated current and voltage values for the double strings, inverter data, and ambient park conditions, such as temperature, solar radiation intensity, and many other things, is collected in 1 to 5 minute intervals and sent every 15 minutes to the Smartblue software manufacturer's server in Munich via the Internet. Here, valuable information is created from the bare numerical sequences.

Special software routines have been developed in order to filter out the relevant information quickly. Error messages with the same cause are summarized in a single message, for instance. Recurring error messages generate a so-called stacking fault that is displayed only once on the control station. For example, in practice this means that a defective module, a blown fuse in the SCB or a loose connector in a string is quickly detected.