Switchgear and method for controlling switchgear

Patent metadata

Field	Value
Publication number	US-2025118509-A1
Application number	US-202218833926-A
Country	US
Kind code	A1
Filing date	Feb 3, 2022
Priority date	Feb 3, 2022
Publication date	Apr 10, 2025
Grant date	—

Abstract

A switch unit is connected between a first node electrically connected to a power source and a second node electrically connected to a load circuit which receives power supplied from the power source. As a current suppression element is connected to the switch unit in parallel. A fault sensing unit senses abnormality in an electrically conducting circuit formed by electrically interconnecting the first node and the second node. When a closing operation of a switchgear is performed, a switching command unit conducts an abnormality diagnosis in a first state in which the switch unit is controlled so that an impedance between the first node and the second node has a first value, and when no abnormal state is sensed in the abnormality diagnosis, the switching command unit controls the switch unit to establish a second state in which the impedance is equal to or smaller than the first value.

First claim

1 . A switchgear comprising:
a switch connected between a first node electrically connected to a power source and a second node electrically connected to a load circuit which receives power supplied from the power source; a current suppressor connected between the first node and the second node in parallel to the switch; a fault sensor to sense an abnormality in an electrically conducting circuit which is formed by electrically interconnecting the first node and the second node and includes the power source and the load circuit; and switching command circuitry unit to control opening/closing the switch, wherein when a closing operation of the switchgear is performed, the switching command circuitry controls the switch to establish a first state in which an impedance between the first node and the second node has a first value, and the switching command circuitry conducts an abnormality diagnosis based on an output of the fault sensor, and when no abnormal state is sensed by the fault sensor in the abnormality diagnosis, the switching command circuitry controls the switch to establish a second state in which the impedance has a second value equal to or smaller than the first value, wherein the current suppressor is an electrical resistance to limit a current, and the switchgear further comprises: a current switch connected between the switch and the second node and opened and closed as controlled by the switching command circuitry, wherein the switch includes an electrical contact or a commutation switch, and the switching command circuitry turns off the switch and turns on the current switch to establish the first state, and conducts a first abnormality diagnosis, the switching command circuitry further turns on the switch and conducts a second abnormality diagnosis when no abnormal state is sensed by the fault sensor in the first abnormality diagnosis, and the switching command circuitry keeps the current switch and the switch turned on to establish the second state when the abnormal state is not sensed by the fault sensor in the second abnormality diagnosis.

2 . (canceled)

3 . The switchgear according to claim 1 , wherein the switching command circuitry turns off the current switch and keeps the switch turned off to terminate the closing operation when the abnormal state is sensed by the fault sensor in the first abnormality diagnosis, and the switching command circuitry turns off the current switch and the switch to terminate the closing operation when the abnormal state is sensed by the fault sensor in the second abnormality diagnosis.

4 . A switchgear comprising:
a switch connected between a first node electrically connected to a power source and a second node electrically connected to a load circuit which receives power supplied from the power source; a current suppressor connected between the first node and the second node in parallel to the switch; a fault sensor to sense an abnormality in an electrically conducting circuit which is formed by electrically interconnecting the first node and the second node and includes the power source and the load circuit; and switching command circuitry to control opening/closing the switch, wherein when a closing operation of the switchgear is performed, the switching command circuitry controls the switch to establish a first state in which an impedance between the first node and the second node has a first value, and the switching command circuitry conducts an abnormality diagnosis based on an output of the fault sensor, and when no abnormal state is sensed by the fault sensor in the abnormality diagnosis, the switching command circuitry controls the switch to establish a second state in which the impedance has a second value equal to or smaller than the first value, wherein the current suppressor is an electrical resistance to limit a current, and the switchgear further comprises: a current switch connected between the switch and the second node and opened and closed as controlled by the switching command circuitry, and wherein the switch includes a commutation switch and an electrical contact connected in parallel, the commutation switch has a larger interrupting capacity than the electrical contact, and an impedance of the electrical contact in an on state is equal to or smaller than an impedance of the commutation switch in an on state, and the switching command circuitry in the first state turns on the current switch and turns off the commutation switch and the electrical contact in the switch, and conducts a first abnormality diagnosis, the switching command circuitry turns on the commutation switch in the switch unit and keeps turned off the electrical contact in the switch, and conducts a second abnormality diagnosis when the abnormal state is not sensed by the fault sensor in the first abnormality diagnosis, and the switching command circuitry turns on the current switch and the electrical contact to establish the second state when the abnormal state is not sensed by the fault sensor in the second abnormality diagnosis.

5 . The switchgear according to claim 4 , wherein the switching command circuitry turns off the current switch and keeps turned off the commutation switch and the electrical contact in the switch to terminate the closing operation when the abnormal state is sensed by the fault sensor in the first abnormality diagnosis, and the switching command circuitry turns off the current switch and the commutation switch and keeps the electrical contact turned off to terminate the closing operation when the abnormal state is sensed by the fault sensor in the second abnormality diagnosis.

6 . A switchgear comprising:
a switch connected between a first node electrically connected to a power source and a second node electrically connected to a load circuit which receives power supplied from the power source; a current suppressor connected between the first node and the second node in parallel to the switch; a fault sensor to sense an abnormality in an electrically conducting circuit which is formed by electrically interconnecting the first node and the second node and includes the power source and the load circuit; and switching command circuitry to control opening/closing the switch, wherein when a closing operation of the switchgear is performed, the switching command circuitry controls the switch to establish a first state in which an impedance between the first node and the second node has a first value, and the switching command circuitry conducts an abnormality diagnosis based on an output of the fault sensor, and when no abnormal state is sensed by the fault sensor in the abnormality diagnosis, the switching command circuitry controls the switch to establish a second state in which the impedance has a second value equal to or smaller than the first value, wherein the current suppressor is an electrical resistance to limit a current or an energy absorbing element having an interrupting capability, the switch includes a commutation switch and an electrical contact connected in parallel, the commutation switch has a larger interrupting capacity than the electrical contact, and an impedance of the electrical contact in an on state is equal to or smaller than an impedance of the commutation switch in an on state, and the switching command circuitry in the first state turns on the commutation switch and turns off the electrical contact, and conducts the abnormality diagnosis, and the switching command circuitry turns on the electrical contact to establish the second state when the abnormal state is not sensed by the fault sensor in the abnormality diagnosis.

7 . (canceled)

8 . The switchgear according to claim 6 , wherein the switching command circuitry turns off the commutation sw

Assignees

• Mitsubishi Electric Corp

Inventors

• Watanabe Shinya
• Okubo Takuya
• Abe Tatsuhiro
• Koyanagi Kimiyuki
• Horinouchi Katsuhiko
• EDO Takahiro

Classifications

• H01H33/08

  Stationary parts for restricting or subdividing the arc, e.g. barrier plate · CPC title

• H02H3/08

  responsive to excess current (responsive to abnormal temperature caused by excess current H02H5/04) · CPC title

• H01H33/59 Primary

  Circuit arrangements not adapted to a particular application of the switch and not otherwise provided for, e.g. for ensuring operation of the switch at a predetermined point in the AC cycle · CPC title

• H01H9/542 Primary

  Contacts shunted by static switch means · CPC title