The increasing need for electricity worldwide is driving the transition towards renewable energy sources on a large scale. The International Energy Agency (IEA) estimates that renewable energy will contribute 70% of the global energy mix by 2050 under a net-zero scenario. Onshore and offshore wind power are expected to play a significant role in achieving this goal. Flow control specialist, Rotork, explains how its electric valve technology is helping to make this possible.
To efficiently transmit the electricity generated by offshore wind farms, which are often located far from the shore, High Voltage Direct Current (HVDC) technology is used. HVDC converter stations play a critical role in this process. They convert the alternating current (AC) electricity generated by wind turbines into direct current (DC) for long-distance transmission with minimal power loss. Upon reaching land, the DC electricity is converted to AC and fed into the power grid.
The flow control of cooling fluids (seawater, deionised water, and glycol) is critical for the regular operation of the platforms. Any technical faults with controlling parameters such as ambient temperature, humidity, and pressure within these platforms could cause the entire wind farm to fail.
Rotork IQ3 Pro electric valve actuators are suitable for this safety-critical application due to their reliability and intelligent features that help reduce unplanned downtime. They only require an electric power source, avoiding the need for additional equipment that might add weight and complexity to the platform. Rotork CVA electric actuators are selected for applications requiring constant modulation. They can provide continuous, repeatable modulating control and a programmed fail-to-position option. The IQ3 Pro and CVA actuators have advanced and user-friendly programming and commissioning technologies and extensive data logging, diagnostic, and asset management capabilities.
HVDC platforms also have safety-critical applications in their auxiliary power units that must reach a failsafe position. Rotork provides two solutions to these needs: the IQ3 Pro Shutdown Battery and the Skilmatic SI3 electro-hydraulic actuator with a mechanical spring-based design. The IQ3 Pro Shutdown Battery includes explosion-proof certification and will continue to operate in uninterruptible power supply (UPS) mode (multiple open/close cycles) until the battery charge runs out. The SI3 uses the same technology as the IQ3 Pro, which helps to standardise the platform’s control system. The compactness and weight of these actuators make them a preferred solution for offshore platforms.
As offshore wind generation moves further from shore, converter platforms and large cable networks are required to reduce transmission losses before the electricity reaches the onshore grid. These converter platforms convert low-voltage energy generated by turbines into high-voltage electricity needed for transmission, providing efficient power delivery over great distances.
Another challenge for any equipment on an HVDC platform is that it is unmanned and fully controlled from the shore. This means that access to this equipment is only possible once a year during the platform’s planned maintenance. This is where Rotork’s Intelligent Asset Management (iAM) solution can help. iAM is a cloud-based system that provides a platform for end-users with advanced condition monitoring of their intelligent actuation and flow equipment.
Users can download the data logs and send them to the iAM system. It helps reduce unplanned downtime by using analytics based on data taken from intelligent actuators to create a maintenance plan. The key areas of information taken from data loggers and uploaded to iAM are torque, temperature, vibration and event log information, and other secondary metrics such as partial stroke profile, maximum starts per hour and motor run time.
Rotork’s range of intelligent electric actuators (isolation and continuous modulating types) and its service offering, including iAM, are well-suited for these challenging applications on unmanned platforms. They provide users with operational insights into the health of their assets and planned maintenance capabilities, which reduces the lifecycle cost of managing these platforms throughout their 25-year lifespan.
