Accurate Condition Monitoring of Semiconductor Devices in Cascaded H-Bridge Modular Multilevel Converters

• This article presents an online condition monitoring (CM) scheme for semiconductors used in modular multilevel converters (MMCs) that comprise cascaded H-bridge submodules. The CM algorithm is based on detecting changes in the ON-state resistance of the semiconductors over time. The proposed method is shown to successfully perform a curve tracing of semiconductors in MMCs while the semiconductor junction remains at a temperature that is readily measurable and undergoes minute changes during the measurement process. The ON-state resistance value is estimated from the measured ON-state voltage drop of the semiconductors and the measured arm current. Measuring the ON-state resistance at known temperatures allows for separating temperature-dependent variations of the ON-state resistance from age-dependent variations of this parameter. Suitable methods for reducing the effect of noise on the curve-traced data are proposed, and a recursive least square estimator is used to extract the optimum ON-state resistance from the traced v(CE) - i

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik -- Annan elektroteknik och elektronik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering -- Other Electrical Engineering, Electronic Engineering, Information Engineering (hsv//eng)

Keyword

Temperature measurement

Semiconductor device measurement

Electrical resistance measurement

Automatic voltage control

Resistance

Monitoring

Voltage measurement

Cascaded H-bridge

condition monitoring (CM)

flexible ac transmission systems (FACTS)

health estimation

modular multilevel converter (MMC)

online monitoring

reliability

semiconductors

Publication and Content Type

ref (subject category)

art (subject category)