Resources Contact Us Home
Coordinated load commutated inverter protection system

Image Number 19 for United States Patent #4475150.

A fault protective system for a load commutated inverter motor drive including an AC to DC source side converter coupled from an AC source to a DC to AC load side converter via a DC link circuit and wherein the load side converter supplies AC power of varying magnitude and frequency to the synchronous motor load. A pair of microcomputers interlinked by a common digital memory respectively control the inverters and interface with hardware type sensor means for detecting the occurrence of a plurality of different types of faults. Additionally, a number of stored instructional sets or programs are respectively included in both microcomputers to detect by software means another plurality of faults. The detection of a fault on either side of the link circuit is communicated to the respective computer which subsequently communicates with the other microcomputer to effect a coordinated protective action in response to thyristor cell failures, circuit failures, and abnormal operating conditions. Cell failure faluts include those instances where a thyristor cell actually fails due to an open or short circuit as well as those cases where a cell fails to commutate properly due to firing strategy problems. Cirucit failures include open and short circuits both in the supply line and the motor leads, while abnormal operating conditions involve such things as low line voltage or excessive motor voltage.

  Recently Added Patents
System and method for multi-threaded OFDM channel equalizer
Reception system including a mechanism countering pulsed interference
Machine shop including computer system that interfaces with different legacy servers
Digital fine delay processing
Wafer recycling method
Method and system for monitoring service quality in a mobile node
Fingerprinting apparatus, system, and method
  Randomly Featured Patents
Screw cover and method
Watch case
Dental flosser and method of manufacturing same
Vibrator for flowing granular material
Path route test apparatus for use in an ATM transmission system
RFID devices using RFID circuits and antennas having unmatched frequency ranges
Article transfer apparatus
Method for manufacturing semiconductor light emitting device
NAND type flash EEPROM in which sequential programming process is performed by using different intermediate voltages
Image inputting device