Name: ARTHUR EDUARDO ALVES AMORIM
Publication date: 20/03/2020
Advisor:
Name |
Role |
|---|---|
| DOMINGOS SÁVIO LYRIO SIMONETTI | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| DOMINGOS SÁVIO LYRIO SIMONETTI | Advisor * |
| FLÁVIO DUARTE COUTO OLIVEIRA | External Examiner * |
| LUCAS FRIZERA ENCARNAÇÃO | Internal Examiner * |
| TIARA RODRIGUES SMARSSARO DE FREITAS | External Examiner * |
Summary: Wind energy conversion systems based on DFIG has significant role in electrical matrix in different countries, following the wind energy production growth. With the major relevance of this kind of generator for the electric utility, grid codes have been updated, restricting more and more the requirements for connection. The whole electrical grid stability could be jeopardized due to a failure in these equipment. The compliance of DFIG-based wind turbines to grid codes ride-through requirements is critical, once this generator is extremely susceptible to grid voltage disturbances. Voltage dips in the turbine point of connection has potential to produce hazardous voltages and currents in rotor circuit. The suitability of DFIG to these new grid codes without compromise its components safe operation have been theme of many researches recently. A proposal to solve this problem is explored in this work.
The proposal presented here uses an alternative converter topology employing a hybrid multilevel converter. Through the text the reasons for the employment of this topology, as well as system design and control strategy are detailed. Results obtained through computational simulation on PSCAD for a 2MW generator are used to demonstrate the effectiveness of the proposed solution. These results show the most important variables of DFIG during balanced and unbalanced voltage dips, as well as DFIGs capability to inject reactive power and to support grid voltage restoration. Besides this, the contribution of this strategy to the power system transient stability is verified. It is proved that, for different scenarios, power generation remains controlled while the currents in the rotor are kept at levels safe for the converter.
