Controllable tripout for an electrical circuit breaker

Patent metadata

Field	Value
Publication number	US-10249461-B2
Application number	US-201715668199-A
Country	US
Kind code	B2
Filing date	Aug 3, 2017
Priority date	Aug 23, 2016
Publication date	Apr 2, 2019
Grant date	Apr 2, 2019

Abstract

A controllable trip device includes a magnetic actuator, including a coupling member intended to be coupled to a switching mechanism of an electrical circuit breaker to cause the switching thereof and a coil configured to displace the coupling member towards a tripped position when it is supplied with a pulse of a current of intensity greater than a first predefined threshold for a duration greater than or equal to a predefined duration, a control device, configured to supply the coil, immediately on receipt of a control signal, with a series of pulses of duration equal to the predefined duration and of intensity greater than or equal to the first threshold and less than or equal to a second threshold equal at most to 120% of the first threshold.

First claim

The invention claimed is:

1. A controllable trip device for an electrical circuit breaker, the circuit breaker being switchable between an open state and a closed state, said trip device comprising:
an actuator comprising a coupling member movable between a rest position and a tripped position, the coupling member being intended to be mechanically coupled to a switching mechanism of an electrical circuit breaker to cause the switching of the circuit breaker from a closed state to an open state when the coupling member goes from the rest position to the tripped position, and
a control device configured to energise the actuator in response to the reception by the trip device of a tripping command signal in order to move the coupling member from the rest position to the tripped position;

wherein the actuator is a magnetic actuator including a coil configured to move the coupling member from the rest position to the tripped position when it is energised by an electrical current pulse of intensity greater than a predefined first threshold (I-min) for a time greater than or equal to a predefined time (T-on) and wherein the control device is configured to energise the coil electrically immediately on reception of the command signal (Vcmd) and for as long as the command signal (Vcmd) is maintained with a series of electrical current pulses having a duration equal to the predefined time (T-on) and of intensity greater than or equal to the first threshold (I-min) and less than or equal to a second threshold (I-max), said second threshold (I-max) being equal at most to 120% of the first threshold (I-min).

2. The trip device according to claim 1 , wherein the command signal (Vcmd) is an electrical voltage received at an input of the trip device, the control device being adapted to be electrically energised by the command signal (Vcmd) and wherein the control device comprises:
a current limited voltage regulated supply connected in series with the coil between the input and an electrical ground (GND) of the control device, said current limited voltage regulated supply being configured to deliver a supply voltage (Vcc) on a supply rail as soon as it is energised by the command signal (Vcmd),
an excitation module configured to be electrically energised by the supply voltage (Vcc) and to control the generation of the electrical current pulses, the current limited voltage regulated source being moreover configured so as alternately to inject selectively into the coil an electrical current of intensity equal to the second predetermined threshold (I-max) and to interrupt the flow of this electrical current in response to tripping and interruption commands generated by the excitation module.

3. The trip device according to claim 2 , wherein the control device includes a controllable switch (T 1 ) connected in series with the coil and the current-limited voltage regulated supply between the input and the electrical ground (GND), the supply being controlled by the excitation module with said switch (T 1 ), the switch (T 1 ) being to this end connected to the excitation module and able to switch between a conducting state and a blocking state in order respectively to allow or to inhibit the flow of the electrical current in response to the tripping and interruption commands generated by the excitation module.

4. The trip device according to claim 2 , wherein the control device includes a probe for measuring the current flowing through the coil and wherein the excitation module is programmed successively to activate and then to inhibit the injection of the electrical current by the current limited voltage regulated supply to generate each electrical current pulse, the excitation module being programmed to command this inhibition on the expiry of the predetermined delay (T-on), said delay being counted down by the excitation module from the time at which the current measured by the measurement probe exceeds the first threshold value (I-min).

5. The trip device according to claim 2 , wherein the excitation module is programmed to detect if the command signal (Vcmd) is a DC or AC electrical voltage and alternately:
to synchronise automatically the generation of the electrical current pulses with the command signal (Vcmd) if the command signal (Vcmd) is detected as being an AC electrical voltage, this synchronisation being carried out by the excitation module by generating the tripping commands at the times at which the command signal (Vcmd) assumes a null value, and
to command the generation of the electrical current pulses with a predefined period if the command signal (Vcmd) is detected as being a DC electrical voltage.

6. The trip device according to claim 2 , wherein the excitation module is programmed to command the generation of the electrical current pulses with a predefined interval (T off) between two consecutive electrical current pulses, the predefined interval (T off) being less than or equal to 100 ms.

7. The trip device according to claim 2 , wherein the cyclic ratio between the predetermined time (T-on) and the predefined interval (T-off) is between 1/10 and 1/100 inclusive, preferably equal to 1/40.

8. The trip device according to claim 1 , wherein the control device includes an analog excitation module configured to generate a single electrical current pulse of intensity greater than or equal to the predetermined first threshold (I-min) immediately on reception of the command signal (Vcmd) by the control device.

9. The trip device according to claim 1 , wherein the actuator further includes a magnet, a mobile part mechanically connected to the coupling member and a tripping spring, the magnet being secured to a fixed part of the actuator and exerting a magnetic force on the mobile part when the coupling member is in the rest position so that the mobile part compresses the spring to retain the coupling member in the rest position, the spring exerting a return force opposing the magnetic force and less than the magnetic force, the coil being adapted to reduce the force of magnetic attraction exerted by the magnet when it is energised by each of said electrical current pulses applied by the control device so as to allow the movement of the coupling member from its rest position to the tripped position because of the effect of the return force exerted by the tripping spring.

10. An electrical switchgear including a circuit breaker and a controllable trip device associated with the circuit breaker,
the circuit breaker including a switching mechanism intended to switch the circuit breaker between an open state and a closed state,
the trip device including:
an actuator comprising a coupling member movable between a rest position and a tripped position, the coupling member being mechanically coupled to the switching mechanism to cause the switching of the circuit breaker from the closed state to the open state when it goes from the rest position to the tripped position, and
a control device configured to energise the actuator in response to the reception by the trip device of a tripping command signal (Vcmd) to move the coupling member from the rest position to the tripped position;

wherein the actuator is a magnetic actuator including a coil configured to move the coupling member from the rest position to the tripped position when it is energised with an electrical current pulse of intensity greater than a predefined first threshold (I-min) for a time greater than or equal to a predefined time (T-on) and wherein the control device is configured to energise the coil electrically immediately on reception of the command signal (Vcmd) and for as long as the command signal (Vcmd) continues to be received by means of a series of elec

Assignees

• Schneider Electric Ind Sas

Inventors

• Bordet Bruno
• Urankar Lionel

Classifications

• H01H2071/665

  the reset mechanism operating directly on the normal manual operator, e.g. electromagnet pushes manual release lever back into "ON" position · CPC title

• H01H71/24 Primary

  Electromagnetic mechanisms · CPC title

• H01H71/68

  actuated by electromagnet · CPC title

• H01H2300/024

  Avoid unwanted operation · CPC title

• H01H47/04

  for holding armature in attracted position, e.g. when initial energising circuit is interrupted; for maintaining armature in attracted position, e.g. with reduced energising current {(with switching regulator H01H47/325)} · CPC title