With the rise of non-dispatchable renewable resources, high-precision photovoltaic monitoring is critical. University of Cordoba scientists developed an innovative "big brother" synchronized sensor system to manage solar data, boosting predictability and optimizing energy prices.
Photovoltaic monitoring, the ‘big brother’ approach is under test
With the growth of non-dispatchable renewable resources on the grid, photovoltaic monitoring has assumed a leading role. In recent years, new and increasingly advanced measurement technologies have progressively entered the market with the goal of making solar production more predictable and manageable.
This constant focus on operations, including infrastructural operations, has inadvertently created another type of challenge: an enormous quantity of data. How can this data be managed optimally? A group of scientists from the University of Cordova, who created an innovative high-precision monitoring system based on a synchronized sensor network, are now providing the answer. To better understand how the system works, a step back is necessary.
Monitoring devices in smart grids
The study is based on a previous investigation that closely analyzed various monitoring devices employed in a smart grid, focusing on the communication systems of three advanced instruments:
- Micro-phasor measurement units (μPMU), which measure the amplitude and phase of voltage and current relative to an absolute time reference.
- Smart meters.
- Power quality meters (PQM).
Each of these devices is essential for characterizing photovoltaic (PV) systems, but each also possesses specific characteristics, consequently requiring different transmission speeds and synchronization levels.
Furthermore, each piece of equipment generally uses its own specialized framework. The research goal at the University of Cordova was to integrate the data from these instruments into a single, synchronized system for more efficient and accurate photovoltaic monitoring.
“This is a big brother-style monitoring system,” the university explained, “designed not only to observe and predict the performance of these plants but also to adapt the auction that establishes energy prices to more realistic conditions.“
The extended phasor measurement unit (ePMU)
The team developed and implemented a hardware architecture for monitoring distributed solar resources across two photovoltaic plants. This architecture combines the real-time phasor measurements from the PMUs with the energy production measurements from the compactDAQ, the data acquisition platform created by National Instruments. All measurements were processed by a single device that the authors named the extended phasor measurement unit (ePMU).
The highlight of this approach is that data is collected every tenth of a second, in great detail, so great that it generates approximately 2-3 gigabytes of data per month. Furthermore, because the devices are synchronized with each other and positioned in different areas, the information they provide allows researchers to see precisely what happened and to predict what will happen. This level of detail in photovoltaic monitoring is groundbreaking.
As UCO researcher Víctor Pallares López pointed out, “This is about carefully monitoring the systems to collect as much information as possible and being able to react to any negative effect that could compromise the stability of the electric grid.”
The work was published in the article, “Implementation and characterization of a high-precision monitoring system for photovoltaic power plants using self-made phasor measurement units,” which appeared in the IEEE sensors journal.
