Operating wind power stations with high availability

Electrical safety in wind turbines

Generator

Economic factures dictate the need for high reliability and uptime in power generating wind turbines. The wind turbines electrical generating system employs a variety of technologies depending on the manufacturer. There are the typical asynchronous machines, where there is often two generators employed in a single turbine. A larger one for higher and a smaller generator each designed to operate at the higher and lower wind speeds. These are usually directly coupled to the grid via a transformer. There are also permanent magnet brushless generators that will indirectly feed the grid via a converter drive. All the electrical systems above are constantly exposed to excessive vibrations, wear and tear and hazards. Based on their constructive nature, lightning strikes are also a huge problem. Bender mitigates the risk associated with these issues by employing a variety of ground fault detection, insulation monitoring and fault location units in these demanding environments. Unplanned downtime and time consuming fault location issues will be reduced to a minimum.

Product overview ISOMETER®
Market segment brochure Renewable Energy
Technical paper Insulation fault location - Planning and set up in the solar charging station at the University of Applied Sciences Bingen
Technical paper Answers for tomorrow
Technical paper: Fire safety in wind power stations

Recommended systems for ground-fault detection (ungrounded systems):

Recommended systems for ground-fault location:

DIN EN 61400-2
Wind turbines - Part 2: Requirements for small wind turbines

DIN EN 60255-127
Measuring relays and protection equipment - Part 127: Functional requirements for over/under voltage protection

DIN EN 50178
Electronic equipment for use in power installations

Ground fault protection for general low voltage control systems in wind turbines

Control voltage

Power for a wind turbines controls and operation are usually being fed from an external source. The feed to the turbine should be monitored at all times for its electrical integrity since losing the source will render the revenue producing turbine inoperable until the problem is fixed. Benders ground fault monitoring systems ensure that the supply to the turbine is constantly protected and supervised for electrical breakdown situations.

Product overview ISOMETER®
Market segment brochure Renewable Energy
Flyer Safe connection to the grid
Technical paper Insulation fault location - Planning and set up in the solar charging station at the University of Applied Sciences Bingen
Technical paper Electrical safety in control and auxiliary circuits
Technical paper Answers for tomorrow

Recommended systems for ground-fault detection (ungrounded systems):

Recommended systems for ground-fault location:

Recommended systems for ground-fault monitoring (grounded systems):

Recommended systems for condition monitoring:

DIN EN 61400-2
Wind turbines - Part 2: Requirements for small wind turbines

Anti islanding protection relay

Safe voltage and frequency levels

Network and system protection

Alternative energy sources feed in points must be constantly monitored and switched off in case the main power grid drops off. This practice is known as anti-islanding protection. The Bender VMD460 relay series checks whether frequency and voltage limits are within range. Additional features such as ROCOF (Rate of change of frequency) and vector jump recognition are added to ensure a proper alert to a missing grid. The three phase VDM460 relay comes with preconfigured setting to fulfill the relevant standards such as IEEE1547 but can also be configured via menu by the touch of a button.

Flyer Safe connection to the grid

Recommended measuring and monitoring relays:

CEI 0-21
Regola tecnica di riferimento per la connessione di Utenti attivi e passivi alle reti AT ed MT delle imprese distributrici di energia elettrica (Reference technical rules for the connection of active and passive consumers to the HV and MV electrical networks of distribution Company)

VDE-AR-N 4105
Anwendungsregel:2011-08 Erzeugungsanlagen am Niederspannungsnetz Technische Mindestanforderungen für Anschluss und Parallelbetrieb von Erzeugungsanlagen am Niederspannungsnetz

C10/11
Specifieke technische aansluitingsvoorschriften voor gedecentraliseerde productie-installaties die in parallel werken met het distributienet

BDEW-Richtlinie

DIN VDE 0126-1-1/A1
Selbsttätige Schaltstelle zwischen einer netzparallelen Eigenerzeugungsanlage und dem öffentlichen Niederspannungsnetz (Norm wurde zurückgezogen und durch DIN VDE V 0126-1-1 ersetzt)

G59/2
Recommendations for the Connection of Generating Plant to the Distribution Systems of Licensed Distribution Network Operators

G59/3
Recommendations for the Connection of Generating Plant to the Distribution Systems of Licensed Distribution Network Operators

G83/2
Recommendations for the Connection of Type Tested Small-scale Embedded Generators (up to 16A per phase) in parallel with Low Voltage Distribution Systems

G83/3
Recommendations for the Connection of Type Tested Small-scale Embedded Generators (up to 16A per phase) in parallel with Low Voltage Distribution Systems

Ground fault protection for wind turbine pitch control systems

Pitch-Control

Pitch control systems are vital for operating a wind turbine at its maximum peak power output. electrical faults can render the pit control useless which will result in the turbine getting stuck at a certain pitch, or worse may even stall the turbine and drive its output to zero until the problem is fixed. Bender RCMS ground fault monitoring systems constantly record such a systems electrical leakage towards the turbines chassis. Once the preset thresholds have been breached, the system alerts the personnel as to the level and the exact location of the problem.

Product overview Residual current monitoring
Market segment brochure Renewable Energy

Recommended systems for ground-fault monitoring (grounded systems):


Ground fault protection for azimuth control systems in wind turbines

Follow the wind for the highest efficiency and safety level

Azimuth control

Azimuth or yaw control systems are gear drive systems designed to direct the wind turbine towards the wind, or in very extreme conditions, may even direct the turbine out of the wind. The system usually consists of a wind direction sensing vane, coupled to a gear drive and electrical motors. A ground fault in the azimuth control can disable the turbines “sense of direction” and will pretty much render it unproductive. Benders RCMA and RCMS ground fault monitoring units will sense an electrical failure at very low levels and alert personnel before the situation worsens.

Product overview Residual current monitoring
Market segment brochure Renewable Energy
Flyer Safe connection to the grid

Recommended systems for ground-fault monitoring (grounded systems):


Communication

Communicating electrical safety from the wind plant to the operator

Communication

Bender's COMTRAXX gateways communicate the insulation and ground fault values from the wind power plant via Ethernet/TCP-IP or Modbus to the higher level supervisory systems or the operators for a clear concise picture of the overall turbines electrical health. 

Market segment brochure Renewable Energy
Flyer Safe connection to the grid