Investigation of wind turbine generator cables and their impact on waveform deterioration by means of experiment and circuit simulation
Authors
Deininger, Tim Nathanael ; Beland, Lennart Hermann
Term
4. term
Education
Publication year
2019
Submitted on
2019-05-31
Pages
123
Abstract
Efterhånden som vindmøller får højere effektniveauer, undersøges nye måder at placere de elektriske konverteringsled på. En mulighed er at flytte den back-to-back-konverter, der afkobler generatoren fra elnettet, fra nacellen (huset øverst på tårnet) til tårnfoden. Det giver 100-200 m kabel mellem generatoren og konverteren på jorden, hvilket kan medføre, at hurtige spændingspulser reflekteres ved kabelsamlinger og skaber overspændinger, som belaster generatorens viklinger. For at undersøge disse effekter er der opbygget en lavspændingsopstilling, der efterligner denne vindmølletopologi og fungerer som en nedskaleret validering. Samtidig er der modelleret et elektrisk kredsløb med generator, kabler og aktiv ensretter, der afspejler forsøgsopstillingen. Generator- og kabelkomponenter er parametrisert ved hjælp af impedanstilpasning, så modellen matcher den observerede adfærd. Med denne validering som grundlag udføres mellemspændingssimuleringer for at få indsigt i en forventet praktisk anvendelse. Dette gør det muligt at vurdere, om et dV/dt-filter, der begrænser hastigheden af spændingsændringer, kan være en gennemførlig løsning. Når overspændinger dæmpes, beskyttes generatorens viklinger mod skadelige mekaniske og elektriske belastninger.
As wind turbines increase in power, engineers are exploring new layouts for the electrical conversion stages. One option is to move the back-to-back converter that decouples the generator from the grid from the nacelle (the housing at the top of the tower) to the tower base. This creates 100-200 m of cable between the generator and the ground-level converter, which can cause fast-switching voltage pulses to reflect at cable junctions and produce overvoltages that stress the generator windings. To study these effects, a low-voltage test setup was built to emulate this wind turbine topology and serve as a down-scaled validation. In parallel, a circuit model of the generator, cables, and active rectifier was developed to mirror the experiment. Generator and cable components were parameterized by impedance fitting so the model matches the observed behavior. Based on this validation, medium-voltage simulations were run to gain insight into the expected application. This enables an assessment of whether a dV/dt filter, which limits the rate of voltage change, is a feasible solution. With overvoltages suppressed, the generator is protected from harmful electrical and mechanical stresses in its windings.
[This abstract was generated with the help of AI]
Keywords
Documents