About FlexH2 Project
The Shell-led research project FlexH2, which stands for Flexible Offshore Wind Hydrogen Power Plant Module, intends to develop and demonstrate technology that will accelerate the scale-up of offshore wind, green hydrogen production and its integration in the energy system. Through this grant, the government is contributing 4 million euros, the partners are investing about
5 million euros in the project. The research project is to start on April 1st 2022 and will last four years.
FlexH2 is based on three key technological innovation pillars: (1) a grid-forming offshore wind farm, (2) a high-performance AC/DC solid-state transformer for large-scale electrolysers, and
(3) a multi-terminal hybrid HVDC transmission system and its energy system integration. The project will determine the optimal design and operational solutions for these pillars. FlexH2 will also demonstrate the feasibility and inter-operability of these key technologies at a medium voltage level, which is crucial to boost the confidence of the FlexH2 concept for application in commercial projects.
FlexH2 brings together stakeholders ranging from technology providers to end-users of various kinds. General Electric, ABB, VONK, TU/e and TU Delft will develop the electro-technical innovations. Shell, Van Oord, TKF, TNO and DNV will use their expertise related to hydrogen electrolysis, balance of plant, market/flexibility, and key component design, transport and installation expertise, respectively.
For more information, please check: https://grow-offshorewind.nl/newsitem/flexh2 About this position
This PhD position aims to develop the third innovation pillar of the FlexH2 project, .i.e, multi-terminal hybrid HVDC transmission system and its energy system integration.
The traditional point-to-point (P2P) HVDC connection is capable of transmitting power generated by offshore wind to shore without technology challenges (e.g. charging current, and dynamic stability) typically faced by long HVAC connection. Despite superior technical capability for far-shore power transmission, P2P HVDC suffers from high cost because of the complex and heavy offshore platform (including converter station topside) compared to its HVAC counterpart. Additionally, the P2P HVDC connection requires dynamic voltage support from the onshore power grid to transfer power to the electric power grid or green hydrogen production in the vicinity; The onshore converter station (point-to-point HVDC connection) is required to be sized the same as the offshore wind farm. This proposed multi-terminal hybrid HVDC system enables lightweight and lean diode rectifier concept to be deployed with the support of a grid-forming offshore wind farm. Furthermore, the novel two-terminal onshore converter station creates electrical infrastructure to directly transfer green electricity to hydrogen electrolysis production independent from the electric power grid connection. The power grid converter terminal can be sized and operated flexibly according to the anticipated flexibility delivery from the FLexH2 concept and the local grid strength condition.
The expected results of the PhD project will be as follows
- Offshore diode rectifier unit integration with grid-forming offshore wind farm for renewable power production.
- Onshore MMC-VSC directly coupled with water electrolysis for green hydrogen production.
- Onshore MMC-VSC station coupled with power grid for flexibility delivery.
- Power plant controller that enables flexible operation of FlexH2 concept.
The PhD candidate will collaborate closely with consortium partners Shell, GE-grid Solution, TKF, Van Oord, TUD, Vonk, TNO to address the following challenges:
1. High voltage diode rectifier unit
- High voltage AC input interface specification
- Rectifier transformer and filter electrical design
- System integration with grid-forming wind power plant
2. Flexible MMC-HVDC grid interface
- Grid interface control design and protection
- Grid interface control verification in controller hardware in the loop platform
3. System integration of SST for hydrogen electrolysis
- Hydrogen interface control design and protection
- Hydrogen interface control verification in EMT simulation with high fidelity OEM specific MMC-VSC control and protection model.
4. Power plant controller for offshore wind hydrogen power plant module
- Primary droop control for grid-forming offshore wind farm, hydrogen interface converter and grid interface converter to maintain the power balance and stabilize dc-link voltage under normal operation
- Secondary emergency power control through communication network under large disturbance caused by loss of generation or load
- EMT simulation and validation in PSCAD/EMTDC
5. Control Implementation and validation in MV-KW FlexH2 Concept Demonstrator
- Control implemntation and testing of Grid Interface
- Control implemntation and debugging of Hydrogen Interface and electroyser emulator
- Integration of wind-farm and DR-HVDC emulator
- Validation of power plant controller and flexH2 concept