Offshore Grid Access Solutions
Siemens AC technology
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Offshore Grid Access Solutions
Siemens AC technology
Good news for offshore platform operators who are seeking innovative, eco-friendly, and reliable AC transmission solutions – Siemens has recently launched the latest innovation for offshore grid access, an AC Technology called offshore transformer module (OTM). The innovative AC technology is based on Siemens' extensive experience along the entire supply chain from power generation via power transmission and distribution. Compared to conventional AC technologies, Siemens' AC grid access solution increases AC transmission reliability and economic efficiency while maximizing the value-add for maintainability.
The innovative AC technology is the right choice for you if your offshore wind farm is less than 80 kilometers away from the coast. Siemens' new AC Offshore Grid Access Solution using Offshore Transformer Modules, in short SGA-OTM, saves space, weight and costs, while improving overall flexibility. With Siemens' AC Grid Access Solution you can also power offshore oil and gas platforms from the shore – allowing for a safe, environmental-friendly and reliable energy supply.
Better performance, easy maintenance, innovative technologies down to the core: The technical backbone of Siemens' SGA-OTM is an offshore platform with gas-insulated switchgear (GIS) in medium and high voltage, transformers and a control & protection system.
The AC transmission to the mainland is realized via undersea cables. Onshore, Siemens installs a state of the art converter station, and if required the innovative, containerized SVC PLUS for reactive power compensation. All electrical components are proven and optimized from Siemens' accumulated life cycle experience. In addition, a modular approach enhances operational performance, maintenance, and availability.
Smaller, lighter, better – the new Siemens innovative SGA-OTM design for connecting near-shore wind power plants to the grid is based on a distributed substation concept with two 250 MW offshore substations in line. The newly developed offshore substation is called an offshore transformer module (OTM) and offers many benefits compared to conventional platform solutions:
This is made possible by implementing plug-and-play principles with containerized and encapsulated equipment. This eliminates the need for a special heavy lift vessel for the installation. Furthermore the OTM is fire safe and environmentally friendly due to the use of a nonflammable, highly biodegradable fluid called ester liquid.
Thanks to a space-saving arrangement and optimized design, the OTM can be installed between the foundation and turbine shaft like a balcony. As an alternative, the offshore transformer module can be installed on a wind turbine foundation separately. Thanks to its modular, simple and rugged design the solution is suitable for all kinds of wind turbine models.
Proven, reliable, durable – for oil and gas fields with less than 50 MW capacity and within 170 kilometers from the shore, AC Technology including a FACTS device is the solution for grid connection.
These flexible AC transmission systems (FACTS) enable steady-state and dynamic voltage control, reactive power control of dynamic loads, and active damping of power oscillations. FACTS access technology therefore offers high flexibility for the integration of various energy sources and strengthens the grid.
Being part of the FACTS product portfolio, Siemens’ trendsetting VSC technology SVC PLUS with “Modular Multilevel Converter” (MMC) design, increases the reliability of the system and improves stability and voltage quality. The pretested, standard modular units of ±25, ±35, or ±50 MVAr guarantee fast implementation and can be operated individually or in parallel. SVC PLUS is outstandingly compact, and is offered in a containerized solution featuring superior operation and footprint flexibility.
The Siemens portfolio includes air-insulated (AIS) and gas-insulated switchgear (GIS), enabling customers to connect offshore application to the power grid through substations for all voltage levels.
The world's longest offshore AC connection: Martin Linge oil platform
A challenging 160 kilometers off the Norwegian coast – Total’s Martin Linge oil production platform has to comply with Norway‘s efforts to fulfill its CO2 emission reduction obligations in accordance with the Kyoto protocol and hence, the operator decided to use power from shore. The Siemens solution consists of a customized turnkey solution with 9 bays of 100kV GIS, 2x 80MVA transformers and Siemens SVC PLUS (2x SVC Plus container solutions, each +/- 50 MVAr) to handle the above-average demand for reactive power compensation. This connection is the world’s longest offshore AC connection of a production platform.
An offshore AC connection for 270 megawatts wind power: Lincs wind farm
The 75 Siemens wind turbines of the Lincs wind farm are located 8 kilometers offshore, near Skegness, Lincolnshire on the east coast of the United Kingdom. The wind farm has an installed electrical capacity of up to 270 MW – enough to power approximately 200,000 homes in the east of England. To ensure a reliable transmission of the wind power, Siemens supplied an offshore substation platform, which bundles the power before it is transported via high-voltage cables to the mainland. The substation is equipped with two 240 MVA transformers as well as 132 kV high-voltage and 33 kV medium-voltage switchgear. In addition to the offshore substation, Siemens also supplied two 300 MVA power transformers (400/132/13.9 kV), two filters, 132 kV and 400 kV switchgear, and a reactive-power compensation system for the onshore substation.
Four times a year, the HDVC/FACTS Highlights newsletter informs about proof points in outstanding projects, new developments and innovative solutions. This issue the Newsletter looks into the next generation of offshore power transmission.
Embedding dispersed generators, such as offshore wind farms in the power systems requires a higher investment in access technology and greater complexity in electrical design. The grid stability and transmission distance are both challenges that have to be taken into account. Siemens customizes grid access technology to meet specific offshore demands.
We conduct studies to determine the most technically efficient and economically feasible system solution. Whether you need support regarding your project management, commissioning, operations or service and maintenance, Siemens offers services to solve all offshore grid access issues. The portfolio also includes training for your employees and individual fault analysis.
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