Method for identifying element failure in capacitor banks
OwnerHaijie Wanginventor
Life of this patent
Estimating the term…
Abstract
A method for identifying element failure in capacitor banks is provided. Capacitor bank phase current is measured and a zero-sequence or negative-sequence current is calculated or measured. A three-phase voltage is measured from a three-phase bus voltage transformer and a zero-sequence voltage or negative-sequence voltage is calculated. A compensated unbalance current is calculated and compared to a predetermined acceptable range. A failure is identified where the compensated unbalance current is outside the predetermined acceptable range.
Claims23
A method for identifying element failure in capacitor banks, comprising the steps of:
- measuring a capacitor bank phase current;
- calculating a zero-sequence current using the capacitor bank phase current;
- measuring a three-phase voltage from a three-phase bus voltage transformers;
- calculating a zero-sequence voltage using the three-phase voltage;
- calculate a compensated unbalance current using a predetermined capacitor bank nominal impedance number, the zero-sequence current, and the zero-sequence voltage;
- and
- comparing the compensated unbalance current to a predetermined acceptable range, a capacitor bank element failure being identified where the compensated unbalance current is outside the predetermined acceptable range.
A method for identifying element failure in capacitor banks, comprising the steps of:
- measuring a zero-sequence current using a current transformer installed on a conductor between a capacitor bank neutral and a capacitor bank ground;
- measuring a three-phase voltage from a three-phase bus voltage transformers;
- calculating a zero-sequence voltage using the three-phase voltage;
- calculate a compensated unbalance current using a predetermined capacitor bank nominal impedance number, the zero-sequence current, and the zero-sequence voltage;
- and
- comparing the compensated unbalance current to a predetermined acceptable range, a capacitor bank element failure being identified where the compensated unbalance current is outside the predetermined acceptable range.
A method for identifying element failure in capacitor banks, comprising the steps of:
- measuring a capacitor bank phase current;
- calculating a negative-sequence current using the capacitor bank phase current;
- measuring a three-phase voltage from a three-phase bus voltage transformer;
- calculating a negative-sequence voltage using the three-phase voltage;
- calculate a compensated unbalance current using a predetermined capacitor bank nominal impedance number, the negative-sequence current, and the negative-sequence voltage;
- and
- comparing the compensated unbalance current to a predetermined acceptable range, a capacitor bank element failure being identified where the compensated unbalance current is outside the predetermined acceptable range.
Dependencies are inferred from the claim text.