Model-Based Fault Detection and Isolation of a Liquid-Cooled Frequency Converter on a Wind Turbine

Table 4

Severity and occurrence analysis of faults both at startup and runtime phase in liquid-cooled frequency converter.

Assessment ⇒; Fault ⇓	Severity	Occurrence	SO	Priority
Startup faults
Air in cooling system	9	3	27	1
Phase module Cooling channel clogging	9	2	18	1
Runtime faults
Pump delivery pressure Decreasing	8	2	16	2
Pipe clogging	8	2	16	2
Pipe leakage	8	2	16	2
Air-cooled heat Exchanger cooling effect Decreasing	6–8	2	16	2
Valve blockage	6–8	2	16	2
Temperature sensor defect	9	3	27	1
Phase model loosening	9	1	9	3