DFIG stator flux‐oriented control scheme execution for test facilities utilising commercial converters

Abstract

The utilisation of conventional industrial converters for development of doubly-fed induction generator (DFIG) test facilities poses an attractive prospect as it would provide proprietary commercial protection and functionality. However, standard commercial converters present significant challenges in attainable DFIG operational capability. This is due to the fact that they are designed for execution of a limited set of pre-programmed common control modes. They typically do not cater for execution of complicated stator flux-oriented vector control (SFOC) schemes required for DFIG drive control. The research work presented in this study reports a methodology that enables effective implementation of SFOC on industrial converters through a dedicated external real-time platform and a velocity/position communication module. The reported scheme is validated in laboratory experiments on an experimental DFIG test-rig facility. The presented principles are general and are therefore applicable to conventional DFIG drive architectures utilising standard industrial converters.

Stator Electrical Fault Detection in DFIGs Using Wide-Band Analysis of the Embedded Signals From the Controllers

“…Fig. 1 shows that the same spectral content exists in the dand q-axis controller signals, which are due to the origins of the d-and q-axis controller signals, and also the fact that identical tuning procedures were implemented on the d-and qaxis controllers [29].…”

“…This section presents analytical equations to calculate the possible wide-band spectral content of the controller signals in a DFIG with and without SEA. A healthy DFIG is assumed to be electrically balanced; higher order supply harmonics and associated spectral effects are ignored; and, the system is controlled through a conventional stator flux oriented control (SFOC) scheme in this study [28,29,30].…”

“…The converter comprises two CT UNIDRIVE SP-4401 units coupled with a DC link: a grid side (GSC) and a rotor side converter (RSC). A dSPACE real-time platform and a resolver communications module are used to implement a SFOC scheme on the RSC [29,36].…”

“…The bandwidth of the presented FFT results is limited to 800 Hz for the sake of consistency between the simulation and experimental results. Further details, as well as a full list of the parameters of the DFIG test-rig, can be found in [29,36]. A schematic diagram of the laboratory DFIG test-rig is presented in Fig. 14.…”

Doubly Fed Induction Generator Wind Turbine Control Based on a Novel MRAS Observer

“…The control of the DFIG by stator flux orientation [14] stator voltage [15] or air gap flux [16] is a technique synthesized by assuming that the grid voltage is ideal and the stator flux is constant or vary very slowly. However, stator flux introduces high nonlinearity into the system during network fault.…”