Power system protection device with current limiting and controlled switching functions for AC and DC applications

Patent metadata

Field	Value
Publication number	US-12444928-B2
Application number	US-202318220322-A
Country	US
Kind code	B2
Filing date	Jul 11, 2023
Priority date	Jul 11, 2023
Publication date	Oct 14, 2025
Grant date	Oct 14, 2025

Abstract

An art fault mitigator includes a sensor structured to detect at least one of a user within vicinity of the power system protection device, a light within the power system protection device and an overcurrent within the power system protection device; a mechanical switching device including a fast mechanical circuit interrupter and an actuator; a power electronics circuit coupled to the mechanical switching device in parallel and including a current commutator structured to commutate current from the fast mechanical circuit interrupter to the power electronics circuit upon turning OFF of the fast mechanical circuit interrupter, a power electronic circuit interrupter structured to allow the current to ride there-through up to a threshold current, and a current limiter structured to limit the current flowing through the power electronics circuit interrupter; and a controller including a trip control structured to control operations of the mechanical switching device and the power electronics circuit.

First claim

What is claimed is:

1. An arc fault mitigator for a power system protection device, comprising:
a sensor structured to detect at least one of a user within vicinity of the power system protection device, a light within the power system protection device and an overcurrent within the power system protection device;
a mechanical switching device comprising a fast mechanical circuit interrupter and an actuator structured to actuate the fast mechanical circuit interrupter;
a power electronics circuit coupled to the mechanical switching device in parallel, the power electronics circuit comprising a current commutator structured to commutate current from the fast mechanical circuit interrupter to the power electronics circuit upon turning OFF of the fast mechanical circuit interrupter, a power electronic circuit interrupter coupled to the current commutator and structured to allow the current to ride there-through up to a threshold current, and a current limiter coupled to the current commutator and the power electronic circuit interrupter, the current limiter structured to limit the current flowing through the power electronics circuit interrupter within the threshold current; and
a controller coupled to the sensor, the mechanical switching device and the power electronics circuit, the controller comprising a trip control structured to control operations of the mechanical switching device and the power electronics circuit based at least in part on a signal from the sensor,
wherein the trip control is further structured to:
cause the fast mechanical circuit interrupter to be turned OFF upon detecting by the sensor at least one of the user within the vicinity of the power system protection device, or
cause the fast mechanical circuit interrupter to be turned OFF upon detecting by the sensor the light and/or the overcurrent, but not the user, and confirm if the light and/or the overcurrent is an arc fault,

wherein, upon causing the fast mechanical circuit interrupter to be turned OFF upon detecting by the sensor at least one of the user, the trip control is further structured to:
cause the current commutator and the power electronic circuit interrupter to be turned ON upon reaching a first period; and
cause the power electronic circuit interrupter to be turned OFF within a third period.

2. The arc fault mitigator of claim 1 , wherein for confirming if the light and/or the overcurrent is an arc fault, the trip control is further structured to:
cause the current commutator and the power electronic circuit interrupter to be turned ON upon reaching a first period;
initiate current limiting via the current limiter upon reaching a second period; and
determine if the light and/or the overcurrent is an arc fault.

3. The arc fault mitigator of claim 2 , wherein, based on a determination that the overcurrent and/or the light is an arc fault, the trip control is further structured to cause the power electronic circuit interrupter to be turned OFF within a third period.

4. The arc fault mitigator of claim 2 , wherein, based on a determination that the overcurrent and/or the light is not an arc fault, the trip controller is further structured to hand over trip decision control to a main controller of the power system protection device.

5. The arc fault mitigator of claim 4 , wherein for handing over trip decision control, the trip control is further structured to:
cause the fast mechanical circuit interrupter to be turned ON within a fourth period;
cause the power electronic circuit interrupter to be turned OFF; and
hand over the trip decision control to the main controller of the power system protection device.

6. The arc fault mitigator of claim 5 , wherein the first period comprises 200 μs, the second period comprises 350 μs, the third period comprises 2 ms, and the fourth period comprises 10 ms.

7. The arc fault mitigator of claim 1 , wherein the arc fault mitigator satisfies all of current short-circuit withstand requirements comprising a rated short-time withstand current, a rated peak withstand current, and a rated duration of short-circuit.

8. The arc fault mitigator of claim 1 , wherein the power electronic circuit interrupter comprises at least an insulated-gate bipolar transistors (IGBTs) and metal oxide varistors (MOVs).

9. A power system protection device coupled to a power source and a load, comprising:
a main circuit interrupter;
one or more branch circuit interrupters;
an arc fault mitigator coupled downstream to the main circuit interrupter and upstream to the one or more branch circuit interrupters, the arc fault mitigator comprising:
a sensor structured to detect at least one of a user within vicinity of the power system protection device, a light within the power system protection device and an overcurrent within the power system protection device;
a mechanical switching device comprising a fast mechanical circuit interrupter and an actuator structured to actuate the fast mechanical circuit interrupter;
a power electronics circuit coupled to the mechanical switching device in parallel, the power electronics circuit comprising a current commutator structured to commutate current from the fast mechanical circuit interrupter to the power electronics circuit upon turning OFF of the fast mechanical circuit interrupter, a power electronic circuit interrupter coupled to the current commutator and structured to allow the current to ride there-through up to a threshold current, and a current limiter coupled to the current commutator and the power electronic circuit interrupter, the current limiter structured to limit the current flowing through the power electronics circuit interrupter within the threshold current; and
a controller coupled to the sensor, the mechanical switching device and the power electronics circuit, the controller comprising a trip control structured to control operations of the mechanical switching device and the power electronics circuit based at least in part on a signal from the sensor,

wherein upon detecting by the sensor at least the user within the vicinity of the power system protection device, the trip control is further structured to:
cause the fast mechanical circuit interrupter to be turned OFF upon detecting by the sensor at least the user within the vicinity of the power system protection device; or
cause the fast mechanical circuit interrupter to be turned OFF upon detecting by the sensor the light and/or the overcurrent, but not the user, and confirm if the light and/or the overcurrent is an arc fault,

wherein for confirming if the light and/or the overcurrent is an arc fault, the trip control is further structured to:
cause the current commutator and the power electronic circuit interrupter to be turned ON upon reaching a first period;
initiate current limiting via the current limiter upon reaching a second period;
determine if the light and/or the overcurrent is an arc fault; and
based on a determination that the light and/or the overcurrent is an arc fault, cause the power electronic circuit interrupter to be turned OFF within a third period, or
based on a determination that the light and/or the overcurrent is not an arc fault, cause the fast mechanical circuit interrupter to be turned ON within a fourth period, cause the power electronic circuit interrupter to be turned OFF, and hand over trip decision control to a main controller of the power system protection device.

10. A method of mitigating an arc fault, comprising:
providing an arc fault mitigator within a power system protection device, wherein the arc fault mitigator comprises: (i) a sensor structured to detect at least one of a user within vicinity of the power system protection device, a

Assignees

• Eaton Intelligent Power Ltd

Inventors

• Chen Steven Z
• Subramaniam Karthikeyan
• Zhou Xin
• Holp Tyler
• Schroedermeier Andy
• Schmalz Steven

Classifications

• H02H1/0023

  sensing non electrical parameters, e.g. by optical, pneumatic, thermal or sonic sensors · CPC title

• H02H1/0015

  Using arc detectors · CPC title

• H02H7/222 Primary

  for switches · CPC title

• H01H9/542 Primary

  Contacts shunted by static switch means · CPC title