CN-115699239-B - Circuit breaker with electronic trip control

CN115699239BCN 115699239 BCN115699239 BCN 115699239BCN-115699239-B

Abstract

The present invention relates to a circuit breaker with electronic trip control. The circuit breaker is traversed by at least one current path (L1, L2, L3) and is capable of being protected from at least one short-circuit type fault occurring in an electrical circuit connected to the current paths (L1, L2, L3), the circuit breaker comprising a power supply (A), a current detector (D) capable of detecting an electrical current in at least one of the current paths (L1, L2, L3) or the current paths (L1, L2, L3), an electronic trip (3, I2, 4, 5) comprising an electronic processing unit (3), an actuator (1) comprising a coil (10), and a breaking mechanism capable of being actuated by the actuator (1), the circuit breaker further comprising a suppression circuit (2, 2', I1) for suppressing magnetic effects on the actuator that may cause an accidental trip, the electronic processing unit being further configured to be capable of controlling the suppression circuit and coordinating the emission of trip control signals with the control of the suppression circuit so as not to short the coil while the trip is occurring.

Inventors

Vincent Gass
Sylvan Azeman
Alexander Heitz

Assignees

黑格尔电镀物品股份公司

Dates

Publication Date: 20260512
Application Date: 20210422
Priority Date: 20200424

Claims (14)

1. A circuit breaker with electronic trip control, wherein the circuit breaker is traversed by at least one current path and is capable of ensuring protection from at least one short-circuit type fault occurring in a circuit connected to the current path; The circuit breaker includes: a current detector capable of detecting a current flowing in the current path or at least one of the current paths and capable of emitting an acquisition signal representative of the current; An electronic trip comprising an electronic processing unit configured to be able to process the acquisition signal and issue a trip control signal when a trip threshold has been exceeded; an actuator, which is driven to trip by the trip control signal and includes a coil, and A disconnect mechanism actuatable by the actuator to disconnect at least one main contact to interrupt current in the current path, and A power supply; Wherein the circuit breaker further comprises a suppression circuit for suppressing magnetic effects on the actuator that may cause an accidental trip, the suppression circuit being capable of shorting the coil when the circuit is controlled to be in a closed state to perform the suppression, and not shorting the coil when the circuit is controlled to be in an open state, and Wherein the electronic processing unit is further configured to be able to control the suppression circuit and to coordinate the emission of the trip control signal with the control of the suppression circuit so as not to short the coil while tripping occurs.
2. Circuit breaker according to claim 1, wherein the suppression circuit comprises a short-circuit switch controlled by the electronic processing unit and connected directly to the terminals of the coil, or to the terminals of the coil by at least one electrical conductor having zero or negligible resistance and/or by electrical components having zero or negligible resistance.
3. The circuit breaker of claim 2, wherein the shorting switch is a transistor.
4. The circuit breaker of claim 2, wherein the electronic trip comprises a drive switch controlled by the electronic processing unit and triggerable by a trip control signal issued by the electronic processing unit to close to supply current to the coil and perform a trip.
5. The circuit breaker of claim 4, wherein the electronic processing unit is configured to control the shorting switch and the drive switch simultaneously to switch the shorting switch and the drive switch between the closed state and the open state.
6. The circuit breaker of claim 5, wherein the electronic trip further comprises a delay circuit capable of delaying control of one switch to be transitioned from the second state to the first state relative to control of the other switch to be transitioned from the first state to the second state, followed by simultaneous control of the shorting switch and the drive switch to switch one of the shorting switch and the drive switch from the first state to the second state, to switch the other switch from the second state to the first state, and while allowing for faster switching from the first state to the second state than from the second state to the first state.
7. The circuit breaker of claim 6, wherein the delay circuit comprises an electronic circuit connected to the electronic processing unit for controlling the electronic circuit and connected to both the shorting switch and the drive switch, respectively, the delay circuit being capable of distributing a delay of control of one of the shorting switch and the drive switch relative to control of the other switch at an output of the electronic processing unit, followed by simultaneous control of the shorting switch and the drive switch by the electronic processing unit.
8. The circuit breaker according to any one of claims 1 to 7, further comprising a monitoring circuit for monitoring the actuator by checking electrical continuity of the coil to which it is functionally connected, the monitoring circuit being driven by the electronic processing unit, the monitoring circuit being further configured not to perform the monitoring while the suppression circuit is controlled to the closed state to short the coil.
9. The circuit breaker according to any one of claims 1 to 7, wherein at least one current path that may magnetically influence the coil extends at least partially transversely or perpendicularly to an axis of the actuator.
10. A circuit breaker according to claim 3, wherein the transistor is a field effect transistor of the MOSFET type.
11. The circuit breaker of claim 4, wherein the drive switch is a transistor.
12. The circuit breaker of claim 11, wherein the transistor is a MOSFET type field effect transistor.
13. The circuit breaker of claim 6, wherein the first state is an open state and the second state is a closed state.
14. The circuit breaker of claim 7, wherein the electronic circuit is a logic circuit.

Description

Circuit breaker with electronic trip control Technical Field The present invention relates to the field of protecting circuits from faults (e.g., short circuits), and to circuit breakers having electronic trip control. Background The function of a protection device (e.g., a circuit breaker) is to interrupt current in the event of a fault in the circuit. In an apparatus comprising a plurality of protection devices, the protection devices are optionally coordinated such that when a fault occurs in the circuit to be protected, only the protection device closest to the fault trips, thereby avoiding the rest of the electrical apparatus from being taken out of service. This improved method of coordination and protection can ensure continuity of service. Several alternative techniques are known, in particular a current-type selectivity based on the tripping threshold of the upstream and downstream circuit breakers, and a timer-type selectivity comprising delaying the tripping of the upstream circuit breaker so that the downstream circuit breaker trips first when the tripping threshold is exceeded. If the selectivity is ensured to reach the assumed maximum value of the short-circuit current at the installation of the downstream circuit breaker, the selectivity between the upstream circuit breaker and the downstream circuit breaker is referred to as the total selectivity. The selectivity limit is defined as the value of the indicated short circuit current below which only downstream circuit breakers will trip. In electrical protection devices involving selectivity, circuit breakers with electronic trip control ensure protection against at least one type of fault, such as a short circuit occurring in the circuit. When a fault occurs, these circuit breakers can be tripped by opening at least one main contact, thereby interrupting the current in at least one current path through the circuit breaker and functionally connected to the circuit. Such circuit breakers generally include: A current detector for detecting a current in at least one of the current path or the current path. To this end, the current detector comprises current sensors, wherein one current sensor is provided for each current path, and a regulating circuit, which emits an acquisition signal representing the current flowing in the current path; An electronic trip comprising an analog electronic processing unit or a microprocessor-based electronic processing unit configured to be able to process the acquisition signal emitted by the detector and to issue a trip control signal simultaneously or with delay when a trip threshold has been exceeded; An actuator which is tripped by the trip control signal and includes a coil which is an electromagnet coil type coil surrounding a movable iron core, typically an iron core, a compression spring, and a permanent magnet. When the actuator is not tripped, the iron core is attracted by the permanent magnets in the coil. When a trip occurs, the coil is supplied with current and generates a magnetic field opposite to and exceeding that of the permanent magnet, which has the effect of axially moving the iron core with the aid of the thrust of the spring and subsequently actuating the breaking mechanism, and A breaking mechanism, also called locking mechanism, capable of actuating the breaking of the main contacts under the action of the movement of the striker, and A power supply, integrated or not into the electronic trip, for providing energy, i.e. current and voltage, to the electronic processing unit and to the coils of the actuator. The supply of current to the electronic processing unit is usually ensured by at least one current path and a power supply means, for example a current transformer, which is functionally connected to said current path. The circuit breaker further comprises a controlled switch of the transistor (MOSFET) type, normally activated by a trip control signal issued by the electronic processing unit, which, when controlled to a closed state, is able to close a circuit connecting the coil of the actuator to the potential of the power supply and to a reference potential, said closure having the effect of letting a current flow into the coil in order to supply it with current to allow tripping to take place. Typically, these circuit breakers also include a lever projecting from the housing of the circuit breaker and connected to a main contact movable by the breaking mechanism so as to allow manual tripping of the circuit breaker. Furthermore, in such a circuit breaker, the electronic processing unit is also configured to be able to check the electrical state of the coil of the actuator. To perform this check, it is necessary to supply the coil with a current, that is to say a current lower than its rated trip current, or a current low enough not to cause tripping, by means of a monitoring circuit for monitoring the electronic processing unit. A problem encountered with these circuit breakers hav