This paper analyzes the inertial response of an offshore wind power plant (WPP) to provide ancillary services to the power system grid. The WPP is connected to a high-voltage direct-current voltage source converter HVDC-VSC to deliver the power to the onshore substation. The wind turbine generator (WTG) used is a doubly-fed induction generator (Type 3 WTG). In this paper we analyze a control method for the WTGs in an offshore WPP to support the grid and contribute ancillary services to the power system network. Detailed time domain simulations will be conducted to show the transient behavior of the inertial response of an offshore WPP.
2. Inertial response
3. Offshore wind turbine
Fig. 1. Test system schematic
EXPECTED SIMULATION RESULTS:
Fig. 2. ΔT order applied to the controller of the DFIG
Fig. 3. DFIG rotating speed, 150 MW
Fig. 4. DFIG electromagnetic torque, 150 MW
Fig. 5. HVDC link voltage , 150 MW
Fig. 6. HVDC link current, 150 MW
Fig. 7. Real and reactive power (rectifier side), 150 MW
Fig. 8. Real and reactive power (inverter side), 150 MW
Fig. 9. DFIG rotating speed, 180 MW
Fig. 10. DFIG electromagnetic torque, 180 MW
Fig. 11. HVDC link voltage , 180 MW
Fig. 12. HVDC link current, 180 MW
Fig. 13. Real and reactive power (rectifier side), 180 MW
Fig. 14. Real and reactive power (inverter side), 180 MW
Fig. 15. DFIG rotating speed, 200 MW, 12 m/s
Fig. 16. DFIG electromagnetic torque, 200 MW, 12 m/s
Fig. 17. HVDC link voltage , 200 MW, 12 m/s
Fig. 18. HVDC link current, 200 MW, 12 m/s
Detailed time domain simulations were conducted in order to analyze the transients present on the inertial response of an offshore WPP delivering power through an HVDC-VSC link. Several results from transient behavior are presented, these results show that an offshore WPP connected to the grid via an HVDC-VSC link is able to deliver inertial response if it is requested.
These results are important as the WPP importance for the power system is growing and its performance during contingencies must be asured.
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