Investigation of DC link Capacitor Failures in DFIG based Wind Energy Conversion System

Abstract

This paper presents the effects of DC link electrolytic capacitor failure of DFIG based wind energy conversion
system (WECS). The degradation of electrolytic capacitor can lead to the failure of DC link. As DFIG based
WECS utilize low power converter, so there is a need to explore the effects of capacitor failure. This failure
(short circuit of capacitor or open circuit) leads to the power outages, high machine currents, high transient
currents in rotor circuit, low terminal voltage of the generator and increase in generator speed. For this
purpose aggregated model of DFIG is implemented in the MATLAB/ Simulink to study the effects of DC link
capacitor short/open circuit on different parameters of system.
Keywords: DFIG, DC link failure, capacitor short circuit, stator flux orientation, capacitor open circuit