Wind energy has begun to lead the way in alternative energy solutions. Manufacturers of wind turbines face challenges such as reducing downtimes and maintenance work. Some of the demands placed on turbine components include extreme temperature conditions, vibration, oscillation and aggressive offshore air composition.
Keeping wind turbines safely operating is becoming increasingly important as more windmills are built and America begins to use wind as larger source of energy heading into the future.
In the event of a management failure or the failure of individual components, the configurable control system PNOZmulti from Pilz guarantees that the wind turbine is brought to a safe condition for both human and machine. Some of the safe monitoring functions include: emergency stop pushbutton, master low voltage switch, oil pressure protection and hermetic protection for the medium voltage transformer, and pitch system. Additional safe monitoring functions include: limit values for true power, vibration, generator speed, rotor speed and line transposition (monitoring of azimuth position) and signals from the fire detection system.
All the safety functions are created directly on the PC with the PNOZmulti Configurator and can be stored on a chip card and downloaded to the base unit.
By differentiating the reaction to various operational circumstances, the PNOZmulti can clearly reduce the load on mechanical wearing parts. A safe condition for both humans and wind turbine can be achieved by reducing the rotor speed and preventing all movements or by switching off hazardous voltages, provided these are not required for the safety function. With PNOZmulti, manufacturers can avoid unnecessary downtimes and thus increase the cost effectiveness of their wind turbines.
PNOZmulti is available in a coated version for use under extreme environmental conditions. This version can be used in extended temperature ranges, permits condensation and is resistant to aggressive air composition. Also, the configurable control system PNOZmulti can communicate via all relevant fieldbus systems. With PNOZmulti, applications can achieve up to Performance Level (PL) e of EN ISO 13849-1 and Safety Integrity Level (SIL) CL 3 of IEC 62061. PNOZmulti is certified worldwide.
Another benefit of the PNOZmulti is that the user program is password protected, enabling manipulation protection to be differentiated – with a range of access levels for maintenance staff and installation engineers.
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Offshore WIND staff, December 26, 2011; Image: pliz