CN102737917A

CN102737917A - Circuit breaker used for over-current protection

Info

Publication number: CN102737917A
Application number: CN2011100840941A
Authority: CN
Inventors: 郑永刚
Original assignee: SASSIN International Electric Shanghai Co Ltd
Current assignee: SASSIN International Electric Shanghai Co Ltd
Priority date: 2011-04-02
Filing date: 2011-04-02
Publication date: 2012-10-17

Abstract

Disclosed is a miniature circuit breaker used for over-current protection, having protection properties of overload time delay and short circuit instantaneous operation. The circuit breaker of the invention is characterized by adopting a current transformer made from a modified material rather than a traditional bimetallic strip and an energized spiral tube or an oil damping structure to detect overload and short circuit signals, analyzing and judging current signals through a control circuit, applying an obtained result to an electromagnetic release, and pushing a mechanism to unlock by an operation of the release so as to break a main circuit contact and to achieve the protection purposes of overload time delay operation and short circuit instantaneous operation. The circuit breaker of the invention has such advantages unmatched by a traditional circuit breaker used for over-current protection as accurate calibration of the time delay operation, no restriction for environmental temperature, short operation time, and the like.

Description

Overcurrent protection is used circuit breaker

Technical field

The low pressure overcurrent protection that the present invention relates to a kind of family expenses and similar applications is used circuit breaker, more detection that relates to overcurrent of detail, and judgement and final execution.

Figure viewed from behind technology

As everyone knows, overcurrent is divided overload and two kinds of situation of short circuit, from known data and introduction, has dual mode that overcurrent is detected; A kind of is to detect overload current with bimetal leaf; Issue thermal flexure through two genus sheets in the function of current and delay time, final pushing mechanism snap close release and the breaking-off contact system opens the purpose of overload protection; The dynamic and static iron core of installation moves iron core through electromagnetic field effect and detects short circuit current in the energising helix tube; When short trouble took place, big electric current moment produced strong magnetic field in helix tube, and magnetic field promotes the motion of movable contact core; Because the motion of moving iron core makes mechanism's snap close release, thereby breaking-off contact system.

A kind of in addition mode is to adopt the hydraulic-electromagnetic release to realize short circuit and overload protection dropout; Adopting " series connection is threaded off " mechanism, be composed in series by a current sense coil and one group of contact, is a non magnetic phantastron-oil damping pipe in the coil; Iron core is housed, spring and damping fluid in the pipe.Armature connection contact and coil mechanism when contact breaks off, do not have electric current to pass through, and coil does not produce electromagnetic force; When contact closure, surveying has electric current to pass through, and when electric current was less than or equal to rated value, the magnetic flux of coil was not enough to iron core is drawn onto pole shoe; Iron core, armature are all motionless, and contact is kept closed, when transshipping, when promptly electric current is greater than rated value; The suction of coil increases, and iron core is begun to the motion of pole shoe direction, during magnetic resistance in the oil damping pipe reduce gradually, magnetic field force magnetic gradually is big; Iron core and pole-shoe face are held, be drawn to pole shoe by this suction armature, discharge thereby thread off, contact breaks off; When bigger overload or short circuit current occurring, the increase of making a concerted effort of electromagnetic energy is rapid, and coil produces enough big magnetic flux; Iron core is also not moving in the oil damping pipe, and armature just is attracted to pole shoe rapidly and makes the circuit breaker instantaneous trip, and this device produces quicker response under the situation of short circuit.

First kind of scheme since bimetallic material to responsive to temperature; Under the different environment temperature, need to consider to fall the problem of appearance, and the delay time consistency is relatively poor, dispersed big; And second kind of scheme moved in damping fluid owing to iron core; Iron core is upwards or the multiple that moves downward overload time is different, thus the direction of the installation of product just there is certain requirement, and the current limitation effect during to short-circuit protection is also undesirable when using the mode of oil damping to carry out overcurrent protection; So adopt the circuit breaker breaking capacity of this kind scheme lower usually, expection disjunction fault current can not be too big.

In view of the problem and shortage that the real reason of above two kinds of schemes low pressure overcurrent protection exists, the present invention provides the mode of other a kind of detection of excessive current, detects electric current through current transformer, and detection signal gets into control circuit, control circuit output, and release is carried out.

Summary of the invention

For the bimetallic material that solves the overcurrent protection circuit breaker to responsive to temperature; Under the different environment temperature, need to consider to fall hold and the delay time consistency relatively poor; Dispersed big, and oil damping formula structure iron core is upwards or the multiple that moves downward overload time is different, the direction of the installation of product just there is certain requirement; And the also unfavorable problem of current limitation effect the when mode of using oil damping is carried out overcurrent protection during to short-circuit protection; Inventing a kind of overcurrent protection circuit breaker of new shape mode, three functional modules are arranged shown in accompanying drawing 1, is respectively current detecting, control circuit, actuator.

Make Current Transformer 1 detect electric current, current detection signal is exported to control circuit 2 through secondary winding, and 2 pairs of signals of control circuit are judged comparison; Affirmation is the sort of state in normal power supply, overload, the short circuit, and control circuit no-output during normal power supply is when signal is an overload; Circuit will get into the overload time delay module, after the stipulated time of delaying time, export trip signal, when the control circuit input signal is short-circuit condition; Circuit is directly exported trip signal, need not time-delay, the schematic diagram of control circuit such as Fig. 2; Delay circuit increases or reduces delay time according to the size of overload current, the size of overload current becomes anti-time limit characteristic with delay time, when getting into the overload time-delay section of attaching; And the load of power supply circuits failover disappears and when overload fault is disappeared; Control circuit will be jumped out time delay module, get into the normal power supply state, and control circuit gets into next circulation.

Circuit breaker divides 1P, 1P+N, 2P, 3P, five kinds of frame modes of 3P+N; 1P profile, 1P+N, the shared a kind of profile of 2P, 3P, the shared a kind of profile of 3P+N; Three kinds of profiles altogether; The N tape contact of 1P+N and 3P+N but unprotect function, the moving contact of multipole product drives with same rotating shaft, simultaneously closure and disjunction.

Description of drawings

Fig. 1 functional module

Fig. 2 control circuit schematic diagram

Fig. 3-1 1P schematic diagram

Fig. 3-21P+N schematic diagram

Fig. 3-3 2P schematic diagram

Fig. 3-4 3P schematic diagram

Fig. 3-5 3P+N schematic diagram

Symbol description: 1 current transformer: 2 control circuits: 3 releases: 4 main circuit contacts

Embodiment

Circuit breaker of the present invention divides five kinds of structure and specifications, is respectively 1P, 1P+N, 2P, 3P and 3P+N

For the 1P circuit breaker, circuit breaker has one group of dynamic and static contact, and moving contact is through the fixing control of rotating shaft; Through spacing rotation main contact is done to divide closing operation, the connecting rod of actuating mechanism connects with rotating shaft, and mechanism makes to divide closing operation through operating grip control; In handle deciliter operating process, mechanism rod drives rotating shaft and rotates, and release is being controlled the snap close of mechanism; The actuating signal of release is exported by control circuit, and the current signal that current transformer detects is input to control circuit.When main circuit overload and short circuit, current signal input control circuit, circuit are made and are judged back output release action command (operating current); Release is threaded off; The release of push rod pushing mechanism snap close, the structural deterioration of mechanism supports contact is under the effect of contact counter-force and disjunction.

For the 1P+N circuit breaker; Circuit breaker has two groups of dynamic and static contacts, through the fixing control of a rotating shaft, makes closure and breaking operation simultaneously; For main circuit N line only control contact deciliter; No current instrument transformer sensed current signal, 1P+N circuit breaker have with 1P circuit breaker identical actuating mechanism and release, and operating principle and control procedure are also identical with the 1P product.

For the 2P circuit breaker, total is identical with the 1P+N circuit breaker, only is that main circuit N tape has defencive function; Detect current transformer and pass the N line, the detection signal input control circuit is with the detection signal of main circuit phase line L two paths of signals altogether; Input control circuit, when overload and short trouble appear in any one tunnel in this two paths of signals, signal output; The release action, mechanism's release, moving contact disjunction.

For the 3P circuit breaker, circuit breaker has three groups of dynamic and static contacts, through the fixing control of a rotating shaft; Make closure and breaking operation simultaneously, the three-phase main circuit all has current transformer detection failure electric current, exports three road signals altogether and gives control circuit; Circuit breaker is about actuating mechanism and the circuit breaker identical with the 1P circuit breaker; When having any one road signal overload and short trouble to occur in three road signals, release action, three groups of contact disjunctions simultaneously.

For the 3P+N circuit breaker, circuit breaker has four groups of dynamic and static contacts, through the fixing control of a rotating shaft; Make closure and breaking operation simultaneously, for main circuit N line only control contact deciliter, no current instrument transformer sensed current signal; The 3P+N circuit breaker has with 1P circuit breaker identical actuating mechanism and release; The three-phase main circuit all has current transformer detection failure electric current, exports three road signals altogether and gives control circuit, when having any one road signal overload and short trouble to occur in three road signals; The release action, four groups of contact disjunctions simultaneously.

Claims

1. an overcurrent protection is used miniature circuit breaker; Have overload time-delay and short circuit instantaneous operation protective feature, it is characterized in that detecting overload and short-circuit signal and be to use a kind of current transformer that material is processed that improves, this current transformer is the hollow cylindrical iron core and is processed by the soft magnetic material that improves performance; Reel ringwise; The Technology for Heating Processing of the externally-applied magnetic field that the warp regulation requires adds containment vessel, prevents that iron core from damaging.

2. circuit breaker as claimed in claim 1; It is characterized in that the circuit phase line passes the current transformer of input; The instrument transformer secondary winding is with the current detection signal input control circuit, and circuit carries out analysis and judgement to signal, when reaching the conclusion requirement; The output action signal is given release, the release action.

3. circuit breaker as claimed in claim 2 is characterized in that release only is the execution to control circuit output signal, promptly is that release is failure to actuate when not having signal output, when signal is exported, and the release action, the output signal only is " 0 " or " 1 ".

4. like claim 2 and 3 described circuit breakers, when it is characterized in that circuit phase line overload, the signal that current transformer detects increases gradually; Control circuit will be confirmed this variation, get into the overload program, when this overload continues to exist; And after continuing the suitable time, the overload program will be judged, overload signal will be exported to release; Circuit is cut off in the release action, and overload protection characteristics is realized.

5. like claim 2 and 3 described circuit breakers, when it is characterized in that short circuit, current transformer detects signal moment increases, and directly with this signal output, circuit is cut off in the release action to control circuit, and the short-circuit protection characteristic realizes.

6. circuit breaker as claimed in claim 4, when it is characterized in that circuit overloads, control circuit confirms to get into the overload program, and circuit recovers again normally after the overload short-term, and circuit will withdraw from the overload program this moment, get into normal condition.

7. circuit breaker as claimed in claim 6; When it is characterized in that circuit overloads, control circuit gets into the overload program, has served as when live stream is continuous to be increased; Control circuit confirms that prolonging of overload held judgement time will be along with shortening; This is inverse relation between the two, has but served as live stream from diminishing greatly into, and control circuit confirms that prolonging of overload hold judgement time and will increase.