earticle

영어

Switch open fault characteristics and simple diagnosis scheme in a permanent magnet synchronous generator (PMSG) based variable-speed grid-connected wind power conversion are presented. In the back-to-back converter, the failure in switching devices may occur either in a machine side converter (MSC) or in a grid side converter (GSC), which decreases the generator output power and degrades the stability in wind power generation system. To detect such a fault, a monitoring scheme for the second-order harmonic components in the q-axis current is proposed, where the harmonic values are simultaneously observed in the MSC as well as in the GSC to monitor abnormal operation of system. To determine the harmonic values irrespective of operating conditions, the normalized currents are employed for the harmonic calculation. To verify the effectiveness of the proposed fault diagnosis scheme, the comparative simulation results are presented. As a result, an on-line simple diagnosis scheme which monitors the condition of generation system can be realized without requiring any additional hardware equipment.