Monitoring of the aging of the capacitors in a converter by means of capacitance measurement

摘要

A method and a device for converting an electrical current include at least one phase module having an AC voltage connection and at least one DC voltage connection. A phase module branch is disposed between each DC voltage connection and the AC voltage connection. Each phase module branch includes a series circuit of submodules, each having a capacitor and at least one power semiconductor. The apparatus can establish aging of an energy storage device in a simple manner by using a capacitor diagnosis device for a time-dependent determination of the capacitance of each capacitor.