Integrating CompactRIO Meteologgers in a Wind SCADA

Gallery

The equipment used in developing a synchronized multimodule application receives information recorded by various meteorological sensors placed in towers that are typically used to calibrate possible locations for renewable energy plants.

Author(s):
Çenk Seren - Cosinor S.A.
Pedro Pacho - Cosinor S.A.

Since beginning operation in 2007, the Renewable Energy Department has carried out various projects in different fields related to green energy.

The equipment used in developing a synchronized multimodule application receives information recorded by various meteorological sensors placed in towers that are typically used to calibrate possible locations for renewable energy plants. We needed to acquire 4 to 20 mA analog, digital, and frequency signals from all of these sensors. Then we needed to format and store the signals in text files and deterministically date them at 20 Hz frequencies.

In addition, we needed a highly configurable preliminary file to adapt to the varying position, offset, gain, and type of each sensor. The CompactRIO controllers in each tower also needed to be synchronized to receive data at the same time as those placed in adjacent towers.

The files generated by each data logger needed to be transmitted and connected to the SCADA system directly to view the values in real time. We had to create a Web interface to view the status of each data logger individually rather than at the system level.

The application requirements consisted of the following:

• Receive three different signal types: analog, digital, and frequency (pulse trains)
• Configure and program the signals and characteristics (offset, gains)
• Acquire signals at high frequencies
• Synchronize the acquisition of all signals
• Transmit data via an Ethernet network using FTP
• Communicate with the SCADA system via OPC
• Use interchangeable hardware

We chose LabVIEW for its user-friendly software development environment and the NI cRIO-9014 embedded real-time controller for its ability to adjust to our needs. In comparison to the analog and digital signals, acquiring the frequency signals were a challenge, but CompactRIO offered the power and frequency needed for signal acquisition by allowing us to adjust the signal captures through direct programming in the LabVIEW FPGA Module.

Performing period computations on the field-programmable gate array (FPGA) provided a clean frequency signal to work with directly in the CompactRIO real-time controller application. The ability to distribute the computations between the FPGA and the CompactRIO real-time controller application represented one of our biggest requirements, which NI hardware was able to meet.

The NI 9403 bidirectional I/O and NI 9203 C Series analog input modules were the ideal hardware solution to complete the future logger, but we were still missing the synchronization component. At this critical point in hardware development and selection, we considered using a time server for the CompactRIO modules, but rejected the idea because we needed a local area network (LAN), which still had not been installed, and external components for future placement calibrations. We wanted to integrate synchronization in the CompactRIO device to make it autonomous for at least synchronization and production of captured data.

We used the cRIO Gxxx S.E.A. Datentechnik (GSM/GPRS Module) to perform synchronization. This module uses a GPS option to synchronize with the CompactRIO real-time application. The durability of CompactRIO and its ability to adjust to the GPS startup time provided a solution for synchronization. We chose the LabVIEW Datalogging and Supervisory Control Module to communicate with the central system via OPC because it allows us to create our own OPC servers.

To monitor the meteorological variables in real time and apply the full power of the system tools to create historical graphs and charts, we needed the OPC client of our SCADA system to communicate with the OPC server.

The final aspect of the system was the collection of the files produced by the data captured by the CompactRIO units. We wanted to gather these files via FTP through the park network using certain scheduled tasks and store them on a server for future access.

Conclusion

According to COSINOR, LabVIEW and its software modules along with NI hardware provided an effective platform for projects with the characteristics outlined above when performing complicated tasks, distribution, communication, and managing acquired data. The system also demonstrated the multifunctional capability of the cRIO-9014 and the LabVIEW FPGA Module, which have been very useful in the case of frequency signals, taking full responsibility for the computing and thus freeing the real-time microcontroller from this responsibility.

Author Information:
Çenk Seren
Cosinor S.A.
Ribera de Elorrieta, 8
Bilbao
Spain