Data logging in wind farms enhances reliability

In addition to the giant blades of large wind farms, the spread of mini-wind power plants – consisting of blades with a power between ten and 100kW – is increasing worldwide as these help farmers and investors to generate revenue from unproductive lands. These blades need an inverter - an electronic device that treats the energy produced by the generator to modify its electrical quantities, making it suitable for placing it in the operator’s network.

One of the world’s leading manufacturers of mini-wind power inverters is Elpower, an Italian company that exports 60% of its production. Elpower always attaches great importance to the solutions used for remote controlling and data logging of its inverters: “Wind turbines produce money. In case of malfunction, users want immediate responses,” explained Alberto Tescari, Technical Director of Elpower and co-owner. He added, “Monitoring must frequently be carried out remotely, transmitting data over a cellular phone network, because often the wind blades are installed in areas that are difficult to reach, especially in winter.”

Requirements of the new solution

Until 2015, the Elpower solution for remote control and data logging of its inverters was based on a self-assembled PC. This was obviously a very compact system with no fan and SSD storage. In 2015, Elpower felt the need to equip its inverters with a new PC - the former model could no longer guarantee total security in data transmission.

Tescari continued: “The main requirements of the new PC were more processing power to use the latest version of Windows; a good amount of memory to keep the bulk of the data in the inverter and transmit only the most relevant information; small size and low consumption; absolute reliability even with temperatures raising up to 60°C; and excellent immunity to electromagnetic interference generated by the inverter’s electromechanical elements.”

In addition to the technical requirements, Elpower also required long term availability, typical of a product for industrial applications, and of course an affordable price.

Fitlet: the ideal candidate

Elpower then analysed the market offering reliable small fanless PCs with SSD, only considering European suppliers with high reliability and knowledge of the industrial market. However, the idea of purchasing components to fit the new PC into the company was still in the field. The encounter with Fitlet - one of the PCs offered by the London-based Tiny Green PC - marked a turning point in Elpower’s research.

From an initial evaluation, Fitlet has highlighted features superior to the competition which are in line with the Elpower’s requirements. “Its dual core AMD processor provides quadruple processing power over our previous solution. Its size (10.8x8.3x2.4cm) is also very small and the five year warranty offered by Tiny Green PC gives us a remarkable tranquillity from the point of view of reliability,” explained Tescari. “Another important aspect is the low price, which makes it more competitive than our previous PC assembled at home.”

However, datasheets and certifications were just the starting point for Elpower. They wanted to test and measure some of Fitlet’s specifications in its lab. The tests have yielded positive results and highlighted the need to customise the product.

A custom solution

In the customisation phase, Elpower has been able to appreciate the expertise of Tiny Green PC regarding the technical collaboration and relationship with customers. “Among the European companies that supply PCs for industrial applications, certainly Tiny Green PC is not the largest but it is agile and flexible. Its expertise has proved to be an advantage for us.

“Tiny Green PC helped us discuss our needs with a technical expert who, in close contact with the designers, supervised all communications so we get a customised version of the PC that meets our exact requirements. This is very difficult, if not impossible, with the largest suppliers,” added Tescari.

Tiny Green PC has partnered with Elpower and the manufacturer to create a custom version of Fitlet, equipped with a modified firmware to increase immunity to electromagnetic interference and factory configured for specific customer needs, which could also be available in the upcoming years to meet the customer’s stability requirements.

On this basis, Elpower has decided to adopt Fitlet for its inverters. During the first months of operation, the technical collaboration between Elpower and Tiny Green PC has helped to further enhance the solution by replacing, where necessary, some memory components.

Positive balance

From 2015 to date, Fitlet has been installed on approximately 500 Elpower inverters around the world. Some of them are monitored by their end users, some by Elpower. None of the installed PCs has failed and data transmission has always been done regularly.

Approximately two years after the adoption of the new PC, Elpower can then draw a very positive balance, as Tescari explained: “In addition to the indispensable technological upgrades of our inverters, we have achieved two other very important advantages - Fitlet’s competitive price has allowed us to focus more resources on our core business. Moreover, as remote monitoring is working perfectly, we no longer need to send an IT engineer to commission the PC. An electrician can install our inverters and configuration can be done afterwards from our headquarters.

“Fitlet helps Elpower to be more competitive in a technologically advanced global market. We will certainly consider Tiny Green PC for our future needs, for example, for the new energy storage systems we will develop in the coming years,” Tescari concluded.