Offshore grid control of voltage source converters for integrating offshore wind power plants
- Autores: Muhammad Raza
- Directores de la Tesis: Oriol Gomis Bellmunt (dir. tes.)
- Lectura: En la Universitat Politècnica de Catalunya (UPC) ( España ) en 2017
- Idioma: español
- Tribunal Calificador de la Tesis: Dirk Van Troyen (presid.), Andreas Sumper (secret.), Adriano da Silva Carvalho (voc.)
- Programa de doctorado: Programa de Doctorado en Ingeniería Eléctrica por la Universidad Politécnica de Catalunya
- Materias:
- Enlaces
- Tesis en acceso abierto en: TDX
- Resumen
The offshore grid in North and Baltic Sea can help Europe to achieve 2020 and 2030 renewable energy target to counter climate changes . The formation of offshore grid requires the interconnection between several offshore wind power plants with multiple onshore grids. A voltage source converter based high voltage direct current transmission system is suitable to operate such an integrated offshore network. The offshore grid will enhance the trade between countries, provide better infrastructure for offshore wind power plants integration, and improve the energy market.
This thesis presents the control system design of voltage source converter to operate an offshore grid. The offshore grid is built gradually , starting from the integration of a single offshore wind power plan! till combined offshore AC and OC network in arder to perform the power system analysis associated with the networks such as steady-state power flow, dynamic behavior, network stability, and short circuit response. The research presents the method of determining control parameters with respect of power distribution and network stability requirements.
The research presents the frequency and voltage droop schemes to enhance the grid-forming mode of voltage source converter to operate in parallel in the offshore grid. A multi-objectives optimal power flow algorithm is proposed to determine the frequency and voltage droop gains in arder to control !he active and reactive power distribution among converters . Later, the impact of these droop gains on network dynamics and stability are analyzed. The study shows that the converter performance influences the offshore AC network stability in conjunction with the droops control loop.
Furthermore, a short circuit and frequency coordinated control schemes are presented for both offshore wind generation units and grid-forming converters . The frequency coordinated control scheme reduces !he wind power up to the maximum available export capacity after the disturbance in the offshore grid. lt is suggested that !he coordination control mus! have both frequency and over voltage control for improved transient response.
In the end, converter control of mullí-terminal OC network and its integration with the offshore AC network has been presentad. The research demonstrate the converter ability to control the distribution of power among the transmission system while ensuring the network stability. The finding of the research can be applied to derive the information and recommendation for the future wind power plants projects.
