Circuit breaker

Patent metadata

Field	Value
Publication number	US-10978259-B2
Application number	US-201916542354-A
Country	US
Kind code	B2
Filing date	Aug 16, 2019
Priority date	Dec 7, 2018
Publication date	Apr 13, 2021
Grant date	Apr 13, 2021

Abstract

A circuit breaker includes: a live line between a live supply connecting terminal and a live load connecting terminal; a neutral line between a neutral supply connecting terminal and a neutral load connecting terminal; a processing unit; a mechanical switch located in the live line, which mechanical switch is controllable by the processing unit; a trigger for interrupting the live line and/or the neutral line; and an auxiliary line connecting the neutral line with the live line between the mechanical switch and the live load connecting terminal, the auxiliary line including serially a current limiting resistor and a control switch controllable by the processing unit. The processing unit controls the control switch and to open and close at least the mechanical switch for a removal of oxidation layers of mechanical contacts of at least the mechanical switch by controlled arcing.

First claim

What is claimed is:

1. A circuit breaker, comprising:
a live line between a live supply connecting terminal and a live load connecting terminal;
a neutral line between a neutral supply connecting terminal and a neutral load connecting terminal;
a processing unit;
a mechanical switch located in the live line, which mechanical switch is controllable by the processing unit;
a trigger configured to interrupt the live line and/or the neutral line; and
an auxiliary line connecting the neutral line with the live line between the mechanical switch and the live load connecting terminal, the auxiliary line comprising serially a current limiting resistor and a control switch controllable by the processing unit,
wherein the processing unit is configured to control the control switch and to open and close at least the mechanical switch for a removal of oxidation layers of mechanical contacts of at least the mechanical switch by controlled arcing.

2. The circuit breaker according to claim 1 , further comprising a semiconductor switching unit controllable by the processing unit, the semiconductor switching unit being connected parallel to the mechanical switch.

3. The circuit breaker according to claim 1 , further comprising at least one galvanic separation switch controllable by the processing unit, the at least one galvanic separation switch being located in the live line and/or the neutral line.

4. The circuit breaker according to claim 1 , further comprising a buffer capacitor arranged in the auxiliary line, the buffer capacitor being connected serially to the current limiting resistor and the control switch.

5. The circuit breaker according to claim 4 , further comprising a discharge resistor connected parallel to the buffer capacitor.

6. The circuit breaker according to claim 1 , wherein the control switch comprises a semiconductor switch.

7. The circuit breaker according to claim 1 , wherein the control switch comprises an isolated gate bipolar transistor with an antiparallel diode.

8. The circuit breaker according to claim 1 , further comprising:
a supply voltmeter configured to measure a voltage between the live supply connecting terminal and the neutral supply connecting terminal; and
a load voltmeter configured to measure a voltage between the live load connecting terminal and the neutral load connecting terminal.

9. The circuit breaker according to claim 1 , further comprising a bypass voltmeter configured to measure a voltage drop at the mechanical switch.

10. A method for operating the circuit breaker according to claim 1 , wherein, in a turned off state of the circuit breaker an oxidation layer removal step is executed, the oxidation layer removal step comprising the following steps:
closing the control switch;
closing and opening the mechanical switch at least one time to cause controlled arcing in the mechanical switch to remove oxidation layers on its mechanical contacts; and
opening the control switch.

11. The method according to claim 10 ,
wherein a buffer capacitor is arranged in the auxiliary line, the buffer capacitor being connected serially to the current limiting resistor and the control switch; and
wherein at least one galvanic separation switch controllable by the processing unit is located in the live line and/or the neutral line, the oxidation layer removal step further comprising the following steps:
charging the buffer capacitor by closing the control switch and the mechanical switch; and
opening at least the mechanical switch and uncharging the buffer capacitor via the at least one galvanic separation switch to remove oxidation layers on its mechanical contacts.

Assignees

• Eaton Intelligent Power Ltd

Inventors

• Askan Kenan

Classifications

• H01H1/60 Primary

  Auxiliary means structurally associated with the switch for cleaning or lubricating contact-making surfaces (cleaning by normal sliding of contacts H01H1/18, H01H1/36) · CPC title

• H01H2009/543

  third parallel branch comprising an energy absorber, e.g. MOV, PTC, Zener · CPC title

• H01H2009/544

  the static switching means being an insulated gate bipolar transistor, e.g. IGBT, Darlington configuration of FET and bipolar transistor · CPC title

• H02H3/08

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

• H01H9/548 Primary

  Electromechanical and static switch connected in series · CPC title