Grid-forming wind turbine generator exhibits excellent performance in weak grids
providing frequency and voltage support to the grid. However
the integration of a high proportion of power electronic devices may lead to grid harmonic pollution
while failures of renewable energy clusters to ride through
faults can cause transient impacts on the grid
worsening power quality. To address these issues
this paper proposes the utilization of a Unified Power Quality Conditioner (UPQC) based on nine-switch converter to achieve harmonic mitigation and source-grid fault isolation
significantly reducing the risk of converter current exceeding limits. To suppress circulating currents generated by parallel operation of multiple turbines and enhance active support during grid-forming wind turbine cluster fault ride-through
the mechanism of virtual synchronous machine power coupling and transient power angle stability are analyzed. Traditional strategies are improved based on reactive power loop supplementary voltage compensation and adaptive active power control. Simulink simulation results under various operating conditions demonstrate that the proposed topology and control strategies exhibit superior dynamic performance
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