Coordination of voltage and frequency feedback in load-frequency control capability of wind turbine

In close future, with high Wind Power (WP) penetration in the power system, the burden of Load-Frequency Control (LFC) is gradually shifted to Variable Speed Wind Turbines (VSWTs). In order to equip the VSWT with LFC capability to support the grid during sudden load-generation imbalance, sufficient reserve capacity should be procured. This paper addresses the LFC scheme offered by VSWT. Feedback loop of locally measured voltage and frequency data is employed to improve transient and permanent response to achieve faster and more efficient LFC action and voltage regulation. The proposed scheme demonstrates remarkable improvement in transient state of both voltage and frequency profiles in comparison with conventional LFC designs provided by Central Power Plants (CPP) or Wind Power Plants (WPP). Numerical simulations carried out in DigSilent PowerFactory confirm the superiority of proposed methodology used in Permanent Magnet Synchronous Machine (PMSG) connected to 9-bus IEEE standard test system.