Abstract
This paper explores the control, operation, and stability characteristics of grid-forming Type III wind turbines. The paper shows that the grid-forming operation mode requires redesign of only the slower control loops for active and reactive power control, whereas the faster current control implementation can stay the same as grid-following turbines. The paper also shows that grid-forming wind turbines face higher mechanical stress than grid-following wind turbines because of the slower speed of the active power control. This stress, however, can be mitigated using advanced pitch control. The paper compares the stability characteristics of the grid-forming and grid-following operation modes of Type III turbines by comparing sequence impedance responses for both operation modes. It is found that, unlike standard Type III wind turbines, the grid-forming mode substantially reduces the risks of subsynchronous oscillations during operation with series-compensated transmission lines. Moreover, the grid-forming Type III turbines can operate stably with extremely weak grids. The findings of this paper are validated using EMT-PSCAD simulations of a 2.5-MW turbine operating in both grid-forming and grid-following modes.
Original language | American English |
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Number of pages | 10 |
State | Published - 2020 |
Event | 19th Wind Integration Workshop - Duration: 11 Nov 2020 → 12 Nov 2020 |
Conference
Conference | 19th Wind Integration Workshop |
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Period | 11/11/20 → 12/11/20 |
NREL Publication Number
- NREL/CP-5D00-78158
Keywords
- control
- grid-forming
- operation
- stability
- Type III
- wind turbines