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
Pyrazole kinase modulators and methods of use
Estimating travel time
Architecture for accelerated computer processing
Surface acoustic wave resonator for down-hole applications
Method for designing sunlight-reflection and heat-radiation multilayer film
Generating compiled code that indicates register liveness
Data storage device with surface ornamentation
  Randomly Featured Patents
Circulating kill valve
Current transmitting mechanism in magnetic recording and reproducing apparatus
Printing method and apparatus
Automatic ranging current shunt
Homeotropic liquid crystal display with common electrodes parallel and positioned at both sides of pixel electrodes to improve viewing angle
LED dash light
Multidose capsules
Vehicle cowl structure
Human immune therapies using a CD27 agonist alone or in combination with other immune modulators
Electrical connector housing