Monitoring of rotational maximum speed of rotors in wind farms for over speed.

The requirements for motion monitoring systems in wind farms are many and varied. Sigma Hellas provides for this purpose, a full range of electronic motion monitoring systems, many models of which are being used for many years in the industry with demanding operating conditions without any problems and the need for replacement (!).

These are characterized by:

Excellent quality
User friendly handling, programming, and installation
Reliable functionality
Compact, highly durable and robust construction
Relay outputs, analogue outputs, etc to satisfy any application
Zero maintenance cost
Affordable purchase price
With or without digital display

Wind turbines must comply with the Machinery Directive

A wind turbine is by definition a functional machine that falls within the scope of the Machinery Directive (MD) and requires a declaration of conformity in accordance with Annex IIA. Several stand-alone machines that are arranged and controlled to function as an integral whole are also classified as machinery.

The PNOZmulti has been implemented in such wind turbine applications as it responds selectively to trigger devices and signals such as E-STOPs, vibration switches and limit value relays for speed, position and pressure. As the safety system reacts selectively to fault situations, it is possible to reduce forces and torques exactly at the point where they occur and are transmitted as extreme and continuous loads. The benefit is a considerable reduction in the mechanical wear of brakes and gears, for example, resulting in a longer service life.

Previous safety solutions on wind turbines have been based on a simple series connection of safety signals. Logically the reaction is always identical and the wind turbine is stopped hard. The mechanical design must be able to cope with these operating conditions. By using the PNOZmulti, with its differentiated reaction to various operational circumstances, it is possible to achieve a clear reserve of gondola and tower components. Servicing costs fall. Hazards are reduced. With the price of raw materials becoming increasingly expensive, the achievable cost reduction is a welcome, economic side effect.

The PNOZmulti safety system guarantees that the wind turbine is brought to a safe condition for both personnel and material, particularly in the case of a management failure or the failure of individual components.

Wind speed & direction station applications

A complete wind measuring and logging station to monitor the wind speed & direction for feasibility studies and verification of existing installations.

We offer high-speed dataloggers to monitor wind turbine power and their performance. We also offer a wide range of sensors, so that a system can be customized to your wind assessment or wind turbine performance needs.
Our data acquisition systems can monitor conditions at wind assessment sites, at wind farms, and along transmission lines. Key components include dataloggers, sensors, and communications devices, which can be customized for each application.

TELEMETRY - wireless communication for monitoring and control
Many times a cabled connection for signal transmission or equipment control is difficult, expensive or there is not enough time to do it, or all three.

The wireless systems that we offer give a reliable solution with approved and tested telemetry units that operate at license free frequencies, covering distances up to 5km or more with repeaters (depending on terain), for simple or complex and sophisticated applications. Wireless data communication via radio modem provides a means of maintaining communication with for example:

Remote units
Measuring stations
External buildings and unmanned installations
Temporary or mobile sites
Devices for gathering of test readings, controlling or regulating equipment or recording various kinds of alarms.

We offer telemetry solutions as well as radio data modems with optional powerful telemetry functionality for wind farm applications.

Capabilities include:-

High performance narrow band radio link
500mW output power (2W optional)
User friendly GUI setup interface
Repeater function
Alarm function
Pulse counting
4 digital input and 4 digital output lines
4 analogue input and 4 analogue output lines
RS232 and RS485/RS422 data ports as standard
AT command set for integration into customer SCADA applications
License exempt operation at 868MHz or 458MHz.
Other VHF/UHF frequencies to order.