Failure Prediction Of Submodule Capacitors In Modular Multilevel Converter By Monitoring The Intrinsic Capacitor Voltage Fluctuations

Recently, the Modular multilevel converters (MMCs) are rising in Medium and High Power Applications. In MMCs we use Aluminum electrolytic capacitors (AECs) in MMCs as floating capacitors because of  their high volumetric efficiency and economical cost. But as time passes  the capacitance of AECs will reduce and electrolyte is vaporized.  The equivalent series resistance (ESR) of AECs increases which can result in an increase of sub-module (SM) capacitor voltage  ripple, power loss, and could damage the operation of the MMC if used for a longer period. To avoid such harm, observing the wellbeing of capacitors is a significant advance to upgrade the dependability of the MMC by prescient support. This paper displays a failure prediction scheme for SM capacitors in the MMC by observing the SM capacitor voltage deviations. Extended simulation studies are done for a five-level MMC in PLECS stage and checked tentatively. The assessed capacitance through simulations and tests are in close consent to that worth estimated utilizing the LCR meter.