Microgrid Dynamic Performance Improvement Using a Doubly Fed Induction Wind Generator

Abstract

This paper describes a control approach applied on a doubly fed induction generator (DFIG) to provide both voltage and frequency regulation capabilities, and hence, an improvement in the dynamic behavior of a microgrid system. The microgrid system is assumed to be a portion of a medium voltage distribution feeder and is supplied by two distributed generation (DG) units, i.e., a gasturbine synchronous generator and a variable-speed wind turbine with DFIG. A control approach algorithm is proposed for the DFIG unit to improve both voltage and primary frequency controls. Two distinct operation modes, i.e., grid-connected and islanding mode, are used in the proposed approach for proper transfer from normal to islanding operation. Case studies are simulated based on both planned and unplanned islanding scenarios to evaluate the performance of the control approach. The study results show that the proposed control approach for DGs in the microgrid increase the microgrid system's dynamic performance, reduce frequency changes, and improve bus voltages regulation during islanding and autonomous operations.Index Terms-Distributed generation (DG), doubly fed induction generator (DFIG), frequency and voltage controls, islanding, microgrid.

Microgrid Power Quality Improvement by using Dual Output Four-Leg Inverter

“…Figure 5 show input signals and output signals of CBPWM for 11 levels. These output signals in Figure 5 (b) produced by comparison between modulator (sine reference) and carriers (triangles) using equation (3). In the triangle-intersection technique, three reference modulation waves , and are compared with triangular carrier waves to generate the switch gate signals.…”

Fuzzy Control of WT with DFIG for Integration into Micro-grids

“…Among the different wind energy conversion systems, WTs with DFIG can provide the required services without the need of large costs of the power electronics hardware, if adequate control strategies are added (Shahabi et al, 2009). The control flexibility due to the DFIG electronic converter makes it possible to define various control strategies for participation in primary frequency control and voltage regulating support.…”

“…The usual peer-to-peer controller of the DGs converters uses the power vs. frequency droop characteristics in order to produce the active and reactive power reference combined with classical PI controllers, as it is mentioned in the review of state-of -the-art controllers in (Meiqin et al, 2008). In (Shahabi et al, 2009), the classical active power regulation takes into account the phase-locked loop (PLL) dynamics in order to prevent major oscillations from happening when a transition between grid connected mode and autonomous operation mode takes place. In (Brabandere et al, 2007) the primary, secondary and tertiary control algorithms are designed and tested in an experimental setup.…”

Transient Response Improvement of Microgrids Exploiting the Inertia of a Doubly-Fed Induction Generator (DFIG)

“…In former studies the usual "peer-to-peer" controller of the DGs converters uses the power vs. frequency droop characteristics in order to produce the active and reactive reference combined with classical PI controllers as it is mentioned in the review of state-of -the-art controllers in [3]. In [5] a control approach is applied on a DFIG in order to improve the dynamic behavior of a microgrid at the mean voltage side. The DFIG can switch from grid connected control strategy to islanding mode control strategy.…”