In-Situ Monitoring of Converter DC Link Electrolytic Capacitors

01.12.2007 - 30.11.2009
Forschungsförderungsprojekt
Within the applied project a novel concept for moni-toring and managing of the DC link electrolytic capacitors of PWM converters (used, e.g., for drives in large quantities) shall be developed and verified. The new method is based on an in-situ identification of the capacitor's loss resistance (equi-valent series resis-tance ¿ ESR) which is ideally suited for detecting the aging status of the capacitor. The permanent ESR determination allows a timely replacement of the capacitor in order to avoid abrupt converter breakdowns with possibly high consequential costs. The new concept proposes a detection of the ESR via determination of the capacitor losses based on voltage/current measure-ments. The special advantage is, that the principle is insensitive to parameter variations and ideally suited for digital implementation, e.g., utilizing low-cost single-chip microcontrollers. Due to the low realization costs ¿ being almost negligible as compared to the capacitor costs ¿ a very wide application area of the monitoring unit is expected. Furthermore, besides the detection of the aging status the unit also opens a possibility for active voltage balancing in case of series connected capacitors. This commonly is performed by ohmic resistors which, however, cause considerable additional permanent losses. Consequently, the novel monitoring system leads to a substantial improvement of the converter reliability as well as to a significant reduction of the converters stand-by losses.

Personen

Projektleiter_in

Projektmitarbeiter_innen

Institut

Grant funds

  • FWF - Österr. Wissenschaftsfonds (National) Austrian Science Fund (FWF)

Schlagwörter

DeutschEnglisch
PulsumrichterPWM-Converter
ZwischenkreisDC voltage link
Elektrolytkondensator-Überwachungelectrolytic capacitor monitoring

Publikationen