US 11,656,279 B2
Method for monitoring circuit breaker and apparatus and internet of things using the same
Niya Chen, Beijing (CN); Rongrong Yu, Beijing (CN); and Jiayang Ruan, Beijing (CN)
Assigned to Hitachi Energy Switzerland AG, Baden (CH)
Appl. No. 16/756,487
Filed by Hitachi Energy Switzerland AG, Baden (CH)
PCT Filed Oct. 16, 2017, PCT No. PCT/CN2017/106364
§ 371(c)(1), (2) Date Apr. 16, 2020,
PCT Pub. No. WO2019/075612, PCT Pub. Date Apr. 25, 2019.
Prior Publication US 2020/0278397 A1, Sep. 3, 2020
Int. Cl. G01R 31/327 (2006.01); H01H 11/00 (2006.01); H01H 33/66 (2006.01); H01H 33/666 (2006.01)
CPC G01R 31/3275 (2013.01) [H01H 11/0062 (2013.01); H01H 33/66 (2013.01); H01H 2033/6667 (2013.01); H01H 2300/052 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A method for monitoring a circuit breaker, comprising:
measuring at least two types of operating condition related parameters of the circuit breaker during operation of the circuit breaker by at least one sensor;
obtaining first data representing a vector having at least two components respectively representing at least two measurements of the at least two operating condition related parameters;
generating a rectangle envelope on a cartesian plane, the envelope bounded by two threshold ranges concerning the at least two operating condition related parameters, wherein an x-axis of the cartesian plane indicates one of the at least two types of operating condition parameters and a y-axis on the cartesian plane indicates another of the at least two types of operating condition parameters;
generating an elliptical envelope by cutting off vertices of the rectangle envelope and supplementing with each cut-off with a curvature to eliminate missed fault identification and false alarm associated with the rectangle envelope;
judging location of the vector represented by the obtained first data with respect to a vector space defined by the elliptical envelope separating healthy and unhealthy status of the circuit breaker to determine a health status of the circuit breaker; and
generating a signal indicating the health status of the circuit breaker in consideration of the location of the vector if it is outside of the elliptical envelope;
wherein the at least two types of operating condition related parameters of the circuit breaker comprise at least two of: opening/closing speed of a movable contact of the circuit breaker, travel of the movable contact, total travel of the movable contact, over travel of the movable contact, rebound of the movable contact, opening/closing time of the circuit breaker, and opening/closing peak coil electric current of the circuit breaker.