Monitoring system for the capacitor batteries of a three-phase filter circuit

US4419621A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Michael Becker · Knittlingen, DE
• Alfons Fendt · Erlangen, DE
• Dusan Povh · Nuremberg, DE
• Klaus Renz · Fürth, DE
• Gerhard Schuch · Erlangen, DE
• Hermann Waldmann · Radebeul, DE

Key dates

• Filing date: May 20, 1981
• Grant date: Dec 6, 1983
• Expiry date: May 20, 2001

Classification

• Technology area (CPC H): Electricity
• CPC primary: H02H7/16
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

A system for monitoring the capacitor batteries of a three-phase filter circuit. Each capacitor battery is formed of a plurality of parallel legs each having a plurality of sectional capacitors which are connected in series with fuses. Adjacent ones of the sectional capacitors are coupled to one another. In a three-phase system, three capacitor batteries are coupled to one another in a Y-circuit configuration, the Y-circuit node being coupled to a reference potential, illustratively ground. The magnitude and phase of the fundamental frequency component of the current flowing from the Y-circuit node to the reference potential is monitored, variations therein being evaluated to identify defective sectional capacitors. Only variations in the Y-circuit node current which occur rapidly will trigger fault signals, thereby preventing false indications resulting from variations in temperature.