Tesis doctoral de José Luis Domínguez García
Wind power has emerged as one of the most promising renewable energy sources. Currently, the penetration level of wind energy in power systems has led to the modification of several aspects of power system behaviour including stability. Due to the fact of large penetration of wind power, transmission system operators (tsos) have established special grid codes for wind farms connection. These grid codes require wind farms to provide ancillary services to the grid such as frequency and voltage regulation. In the near future, the capability of damping power system oscillations will be required. As a result of the development of such requirements, the concept of wind power plant (wpp) arises being defined as a wind farm which is expected to behave similar to a conventional power plant in terms of power generation, control and ancillary services. as a future grid code will require power oscillation damping contribution, the thesis is mainly focused on the study of the power system stabilizer (pss) capability of wind power plants to damp power system oscillations. The change produced by wind power plants based on different wind turbine technologies on power system small signal dynamics is analysed to determine their possible contribution to damp oscillations. The effect of the distance from the tie line to the wind power plant on the controller response and the influence of wind power plants proximity to synchronous generators are demonstrated to be critical factors. At this point several questions are raised as: what are the most critical factors? How can be ensure a proper contribution, at least the best possible response? Can it be ensured to be independent to the power system and the controller selected? to answer these questions, this thesis conducts research on proper selection of input-output signal pairs to damp out electromechanical oscillations using wind power plants without designing the control. This is necessary to draw conclusions about the power system independently of the particular controller. The capability to damp is a characteristic of the system and should not be affected by a particular controller (pss). First, different analysis techniques considering both controllability and observability measures and input-output interactions are compared. From this comparison, recommendations are drawn to select the best signal pairs to damp power system oscillations considering different approaches, such as single-input single-output (siso) and multivariable control (mimo). Second, a novel criterion to select input-output signals used by a pss based on wpps is presented. Unlike previous results, the proposed criterion considers explicitly local and remote signals in the analysis. Using fundamental design limitations and controllability and observability concepts, the criterion is able to identify the most adequate pair of input-output local signals without designing the controller. finally, due to the increase of wind power generation, even more in offshore locations, and to the concept of an interconnected pan-european network, a new offshore wind power plant ac network similar in design to the european supergrid «supernode’ is analyzed. The cost effect of choosing a non-standard operating frequency on the offshore ac network is investigated. As the offshore ac network is isolated from onshore networks by the use of hvdc links, it may be operated unsynchronized at any desired frequency. The cost associated with operating the network at a fixed frequency in the range 20 to 120 hz is investigated, focusing on the frequency-cost scalings of electrical devices (such as cables, transformers and reactive compensation) and offshore infrastructures.
Datos académicos de la tesis doctoral «Analysis of the contribution of wind power plants to damp power system oscillations«
- Título de la tesis: Analysis of the contribution of wind power plants to damp power system oscillations
- Autor: José Luis Domínguez García
- Universidad: Politécnica de catalunya
- Fecha de lectura de la tesis: 18/09/2013
Dirección y tribunal
- Director de la tesis
- Oriol Gomis Bellmunt
- Tribunal
- Presidente del tribunal: Luis Rouco rodríguez
- enrique Acha daza (vocal)
- (vocal)
- (vocal)