Sensorless Control of Late-Stage Offshore DFIG-WT with FSTP Converters by Using EKF to Ride through Hybrid Faults

Li, Wei, Li, Gengyin, Ni, Kai ORCID: 0000-0002-7467-2921, Hu, Yihua ORCID: 0000-0002-1007-1617 and Li, Xinhua (2017) Sensorless Control of Late-Stage Offshore DFIG-WT with FSTP Converters by Using EKF to Ride through Hybrid Faults. ENERGIES, 10 (12). p. 1939.

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Official URL: http://dx.doi.org/10.3390/en10121939

Abstract

A hybrid fault scenario in a late-stage offshore doubly-fed induction generator (DFIG)-based wind turbine (DFIG-WT) with converter open-circuit fault and position sensor failure is investigated in this paper. An extended Kalman filter (EKF)-based sensorless control strategy is utilized to eliminate the encoder. Based on the detailed analysis of the seventh-order dynamic state space model of DFIG, along with the input voltage signals and measured current signals, the EKF algorithm for DFIG is designed to estimate the rotor speed and position. In addition, the bridge arm open circuit in the back-to-back (BTB) power converter of DFIG is taken as a commonly-encountered fault due to the fragility of semiconductor switches. Four-switch three-phase (FSTP) topology-based fault-tolerant converters are employed for post-fault operation by considering the minimization of switching losses and reducing the circuit complexity. Moreover, a simplified space vector pulse width modulation (SVPWM) technique is proposed to reduce the computational burden, and a voltage balancing scheme is put forward to increase the DC-bus voltage utilization rate. Simulation studies are carried out in MATLAB/Simulink2017a (MathWorks, Natick, MA, USA) to demonstrate the validity of the proposed hybrid fault-tolerant strategy for DFIG-WT, with the wind speed fluctuation, measurement noises and grid voltage sag taken into consideration.

Item Type:	Article
Uncontrolled Keywords:	hybrid fault, doubly-fed induction generator, extended Kalman filter, sensorless control, back-to-back power converter, four-switch three-phase converter
Depositing User:	Symplectic Admin
Date Deposited:	08 Jun 2018 14:59
Last Modified:	19 Jan 2023 01:32
DOI:	10.3390/en10121939
Open Access URL:	https://pdfs.semanticscholar.org/5c82/ed1f519a2349...
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3022102