Power Harmonics Suppression Based Direct Vector Control for Robust DFIG
Operation During Grid Voltage Distortions
Abstract
This research introduces a Power Harmonics Suppression (Damping) based
generation of reference currents for reliable operation of DFIGs with
harmonic distortion in grid voltage. The imbalances and dominant
harmonic components (negative sequence as well as 5 th
and 7 th harmonics) in the grid voltage, induces
stator active and reactive power oscillations of 200Hz, 300Hz, 400Hz and
600Hz. Further this lead to braking & forward torque and unreliable
performance of DFIG aiding to grid instability issues. Thus, a modified
set of current references are created for the d-q axes current
control and these references are designed to reduce the imbalances and
harmonics in electromagnetic torque, as well as stator active and
reactive power, with a single objective of damping power oscillations.
Simultaneously, the GSC is focused on mitigating fluctuations in the DC-
link voltage while enabling UPF operation on the grid side. The novel
current references for RSC and GSC are derived by incorporating negative
sequence as well as 5 th and 7 th
harmonic compensating currents along with the steady state current
references, to acquire the desired targets. The overall system is
validated with PSCAD/EMTDC simulations and using OPAL-RT OP4510
real-time simulator, on a 2.3kVA DFIG.