Control Strategies for Wind Power Integration in Weak Grids

As wind energy penetration rises, many power systems operate with diminishing rotational inertia and rising levels of power‐electronics interfaced generation. Such “weak” grids are characterised by low short‐circuit capacity and heightened sensitivity to voltage and frequency disturbances. Control strategies have evolved from traditional grid‐following schemes, which treat converters as current sources, towards grid‐supporting and grid‐forming approaches that emulate the voltage‐angle and inertial behaviour of synchronous machines. Key techniques include inertia emulation via virtual synchronous generators, adaptive droop control, advanced phase‐locked loop tuning to withstand rapid frequency swings, and the exploitation of DC‐link energy storage in VSC‐HVDC links. Multi‐time‐scale coordination among inner current loops, outer voltage or power loops and supervisory control layers ensures stability while maintaining ride‐through capability and offering ancillary services such as fast frequency response and black‐start capability. Practical deployments demonstrate enhanced damping of electromechanical oscillations and robust operation under faulted or islanded conditions, underlining the global significance of these solutions for reliable wind power integration in grids with limited strength.

Research from Nature Portfolio

Recent work has introduced a novel concept of dynamic power flow tailored to power-electronics-dominant systems, uncovering explicit relations between instantaneous power vectors and voltage components. By moving beyond the quasi-stationary approximation, the study presents a dynamic network model that captures fast converter dynamics and small-signal stability characteristics when interfaced with a weak grid. Simulations demonstrate how this framework can predict stability margins and guide the tuning of inner current controllers and outer voltage loops, offering an improved understanding of oscillatory modes in systems with high converter penetration.

Control Strategies for Wind Power Integration in Weak Grids publication trend

The graph below shows the total number of articles in control strategies for wind power integration in weak grids across all publications each year (not limited to Nature Index journals).

Technical terms

Weak grid: A network with low short-circuit capacity and limited rotational inertia, prone to large voltage and frequency deviations when subjected to disturbances.

Grid-forming control: A converter control mode that actively regulates voltage magnitude and angle, emulating a synchronous generator to establish system strength.

Grid-following control: A converter mode that injects current based on a measured grid voltage reference, relying on an external voltage source for stability.

Inertia emulation: A control technique where power electronics replicate the kinetic energy response of synchronous machines, providing synthetic inertia to support frequency stability.

Virtual synchronous generator (VSG): A control approach that enforces a swing-equation dynamic on converter output, combining droop-based frequency regulation with inertia emulation.

Doubly-fed induction generator (DFIG): A wind generator topology with rotor-side and grid-side converters allowing independent control of active and reactive power.

Voltage source converter (VSC): A power-electronics interface that controls output voltage and frequency through rapid switching, commonly used in HVDC and renewable integration.

References

1. Grid-forming control of doubly-fed induction generators based on the rotor flux orientation. Renewable Energy (2023).
2. Blending HVDC-Link Energy Storage and Offshore Wind Turbine Inertia for Fast Frequency Response. IEEE Transactions on Sustainable Energy (2015).
3. Overview of Frequency-Control Technologies for a VSC-HVDC-Integrated Wind Farm. IEEE Access (2021).
4. Nonlinear Adaptive Robust Control Strategy of Doubly Fed Induction Generator Based on Virtual Synchronous Generator. IEEE Access (2020).
5. The Impact of PLL Dynamics on the Low Inertia Power Grid: A Case Study of Bonaire Island Power System. Energies (2019).
6. Black-Start Capability of DFIG Wind Turbines Through a Grid-Forming Control Based on the Rotor Flux Orientation. IEEE Access (2021).
7. Dynamic Network Characteristics of Power-electronics-based Power Systems. Scientific Reports (2020).