The student Julen Paniagua Amillano obtained an OUTSTANDING CUM LAUDE qualification
The student Julen Paniagua Amillano obtained an OUTSTANDING CUM LAUDE qualification
The student Julen Paniagua Amillano obtained an OUTSTANDING CUM LAUDE qualification
Thesis title: Control of Interlinking Converters for Hybrid AC/DC Power Systems
Court:
- Chairmanship: Josep Maria Guerrero Zapata (Aalborg University)
- Vocal: Pablo García Fernández (Universidad de Oviedo)
- Vocal: Markel Zubiaga Lazkano (Ingeteam)
- Vocal: Daniel Serrano Jiménez (Universidad Politécnica de Madrid)
- Secretary: Ander Goikoetxea Arana (Mondragon Unibertsitatea)
Abstract:
Electrical power plays a very important role in todays society, but the necessity to reduce the greenhouse gas emissions requires to shift the classical fossil fuel-based power generation towards a renewable based model. In this transition, existing power systems need to embrace significant changes.
The operation of renewable-based power systems with a high presence of power converters becomes more challenging since these generators present a reduced inherent inertial response, reduced primary regulation capacity and the power generation is non-schedulable. At the same time, dc power systems are gaining popularity due to the advantages they offer for certain applications. Among the different changes that power systems might undergo in order to make them more controllable, reliable and with a better transient response, it is envisioned that power systems will adopt more modular topologies where different ac and dc subgrids will be combined, forming a grid of grids.
In this scenario, interlinking converters (IC)âwhich are power electronic converters to tie electric gridsâwill have a key role, since they can be employed to interconnect power systems of different natures and characteristics, and offer a high controllability over the flow of power among subgrids. The main purpose of this thesis is to develop, analyse and validate control strategies for ICs that contribute to the transient response of interconnected ac and dc power systems.
In order to achieve this objective, first we propose a power flow-based simulation tool, named as dynamic frequency power flow (DFPF) tool. This tool enables to study the dynamic behaviour of ac, dc and hybrid power system scenarios, and the contribution of ICs and their controls to the transient response of interconnected systems.Then, after carrying out a literature review, two IC controls are proposed in this document. The first technique is named as dual inertia-emulation (DIE) control, and it provides inertial response for both interconnected grids, contributing to improve both systems inertial response. The second technique corresponds to a virtual power line (VPL) control, and makes the IC behave as a traditional power transmission line but it enables to tie power systems of different characteristics and natures. This technique unifies the interconnected power systems in terms of primary reserve and inertia, so the transient response is improved, and it facilitates the flow of power from generation to loading points in a natural way. Simulation results that validate the contribution of the proposed controls to the transient response of the grids and demonstrate their effectiveness under different test cases are provided throughout the document