CN2425423Y

CN2425423Y - PTC arc-extinguishing means

Info

Publication number: CN2425423Y
Application number: CN 00228561
Authority: CN
Inventors: 白晶辉
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-06-19
Filing date: 2000-06-19
Publication date: 2001-03-28
Anticipated expiration: 2010-06-19

Abstract

The utility model relates to a PTC arc-extinguishing means for extinguishing electric arcs generated among contacts of a switch (1) when a current changes, which comprises a current inductive unit (2) connected with the switch (1) in series and a control switch (3) controlled by the inductive unit (2). The utility model also comprises a series branch composed of the control switch (3), a PTC element (4) and a branch current inductive unit (5). The series branch is bridged on both ends of a series loop of the inductive unit (2) and the switch (1). The PTC arc-extinguishing means has the advantages of simple structure, low cost, good arc-extinguishing effect, reliable performance, etc. The utility model can be used for on-off devices for various electric equipment.

Description

The PTC arc-extinction device

The utility model relates to the electrical safety technology, be specifically related to eliminate on the power circuit arc-extinction device that switch, circuit breaker etc. are gone up electric arc, more particularly, relate to a kind of PTC (positive temperature coefficient element) arc-extinction device that can be used for the switch arc suppression in bigger interchange of electric current or the DC circuit.

Existing switch is when breaking circuit, and owing to electric current, voltage sharply change, can form the air ionization phenomenon at the two ends of switch contact is electric arc, and this electric arc is along with the rising of electric current, voltage, and its intensity will strengthen.Electric arc discharges very high-temperature when producing, and is enough to make the contact of switch to be damaged, and also may cause damage even cause fire insulating material and circuit itself simultaneously, and harmfulness is very big.For preventing the harm of electric arc, can take several different methods to come arc extinguishing at present, as: strengthen and turn-off the gap, electric arc is turn-offed after arc length surpasses certain distance; Or with gas electric arc is blown by force, to reach the purpose of blowing the outage arc; And carry out encapsulation process or the like with special material.These methods have certain effect in a way, but its principle all is to adopt to treat to force to turn-off after electric arc produces again, though certain effect is arranged yet resemble this passive type arc extinguishing, but each switch can cause certain infringement to switch itself, turn-off number of times is many more, the arc quenching effect of arc control device is poor more, and the time, longer slightly circuit just closed continuous.Just have to often change the arc control device protective device, and whole arc-control device volume and weight are all very big, overall cost is also very high, and manufacture process requirement is also than higher.

The purpose of this utility model is, a kind of device that is used for eliminating issuable electric arc between switch contact in the electric power system switching circuit is provided, this arc-extinction device, can overcome the above-mentioned shortcoming of prior art, reduce the generation of electric arc effectively, can avoid the damage of electric arc greatly various power devices and switch itself.

The purpose of this utility model is to realize like this, construct a kind of PTC arc-extinction device, be used to eliminate the electric arc that may between switch (1) contact, produce when electric current changes, it is characterized in that, comprise an induction by current unit (2) that is connected in series with switch (1) and can be by the control switch (3) of this sensing unit (2) control contact open circuit/path, comprise that also comprises a described control switch (3), the series loop of PTC element (4) and branch current sensing unit (5), the series loop of described PTC element (4) and described control switch (3) and branch current sensing unit is connected across the series loop two ends of described sensing unit (2) and switch (1).Wherein, described switch (1) can be the device that has all kinds of switching circuit of contact (head).

Wherein, described control switch (3) is often opened, when branch current sensing unit (5) in that to sense electric current little when certain electric current, control described control switch (3) open circuit; When described induction by current unit (2) sensing electric current greatly to a certain degree the time, connect described control switch (3).

Wherein, major loop sensing unit (2), control switch (3) and branch road sensing unit (5) are formed the double-current relay integral body of a special use, and wherein sensing unit (2) is a big current coil wherein; Sensing unit (5) is a little current coil wherein; Control switch (3) is the contact of double-current relay wherein.

Implement PTC arc-extinction device of the present utility model, have simple in structure, characteristics such as cost is low, dependable performance, particularly turn-off principle and tradition has a great difference, promptly adopted active generation of stopping electric arc, this active structure, it is very little to accomplish not have the electric arc that electric arc produces or produce substantially.And the mode of traditional arc extinguishing is, electric arc goes to block by force after producing again; And this apparatus features is the moment that produces at electric arc, carries out the electric arc absorption, thereby reaches the purpose of extinguishing arc, has avoided the generation of electric arc.This PTC arc-extinction device can be used for the various devices that have all kinds of switching circuit of contact (head) the various power devices of open and close that get on, and as electrical equipment, equipment, instrument etc., is particularly suitable for using in the place that DC circuit and some contrast sparks are had relatively high expectations.

Below, in conjunction with the accompanying drawings and embodiments, further specify characteristics of the present utility model, in the accompanying drawing:

Fig. 1 is the principle schematic of explanation PTC arc-extinction device of the present utility model;

As shown in Figure 1, PTC arc-extinction device of the present utility model mainly is made up of PTC device and control loop A.As shown in Figure 1, whole arc-control device and main switch (1) series-parallel connection operation.Square frame dotted line among Fig. 1 is represented whole arc-extinction device, comprise the main circuit current inductor (2) that is connected in series with main switch (1), with main switch (1), main circuit current inductor (2) loop Zhi Huilu in parallel, this Zhi Huilu is connected in series with loop current inductor (5), control switch (3) and a PTC device (4).Wherein control switch (3) often leaves, it is subjected to current inductor in the major loop (2) and a loop current inductor (5) is controlled, when current inductor (2) is sensed in the major loop big electric current, control switch (3) is switched on, sense a loop current hour when a loop current inductor (5), control switch (3) is opened a way.After main switch (1) K closes, sensing main circuit as the CT device (2) of current inductor has electric current to flow through, CT device (2) sends instruction closed control switch (3) K1, make PTC element (4) be in the state in parallel with main switch (1) K by control switch (3) and branch current sensing unit (5), PTC element this moment (4) enters the preparation state.When turn-offing, main switch (1) K (comprises when various self-shields are turn-offed); the electric current that in a flash begin absorb main circuit of PTC element (4) from disconnecting; because PTC element (4) internal resistance when low temperature is very little; so when main circuit current is transferred to by PTC device (4), almost do not have obvious electric current and change.Switch ends voltage on the main circuit does not have significant change yet at this moment, and switch (1) K changes under the voltage of approximate equilibrium, realizes no-spark cut-out major loop substantially.Be subjected to main circuit current to transfer to reason on the PTC device, PTC heats up rapidly by big electric current very the time, when temperature rises to optional network specific digit, the PTC internal resistance is climbed to tens of to hundreds of kilo-ohms, the variation of PTC internal resistance, make back flow current also drop to a milliampere level simultaneously, branch current sensing unit (5) among the controller A measures the change that PTC goes up electric current at this moment, it is little of to a certain degree promptly to detect the PTC electric current, make the instruction of turn-offing K1, because being in a milliampere level, turn-offs control switch (3) K1, the basic no-spark that realizes produces, along with the shutoff of control switch (3) K1, one-period is finished in whole rupturing duty, and this moment, whole arc arrester was in the process of switch next time of waiting for again.When The whole control is in static state, not power consumption of whole circuit, and accomplished disconnected, the full isolation of complete shut-down.Sensing unit (2), control switch (3) and branch road inductive switch (5) can be the double-current relay integral body of a special use, and wherein sensing unit (2) is a big current coil wherein; (5) representative little current coil wherein; Control switch (3) is the contact of double-current relay.PTC is the thermistor of positive temperature coefficient.

Claims

1, a kind of PTC arc-extinction device, be used to eliminate the electric arc that may between switch (1) contact, produce when electric current changes, it is characterized in that, comprise an induction by current unit (2) that is connected in series with switch (1) and can be by the control switch (3) of this sensing unit (2) control contact open circuit/path, comprise that also comprises a described control switch (3), the series loop of PTC element (4) and branch current sensing unit (5), the series loop of described PTC element (4) and described control switch (3) and branch current sensing unit is connected across the series loop two ends of described sensing unit (2) and switch (1).

2, PTC arc-extinction device according to claim 1 is characterized in that, described switch (1) can be the device that has the various control circuit switchings of contact (head).

3, PTC arc-extinction device according to claim 1 is characterized in that, described control switch (3) is often opened.

4, PTC arc-extinction device according to claim 1 is characterized in that, described branch current sensing unit (5) is controlled described control switch (3) open circuit in that to sense electric current little when certain electric current.

5, PTC arc-extinction device according to claim 1 is characterized in that, described control switch (3) is connected sensing electric current greatly to a certain degree the time in described induction by current unit (2).

6, according to each described PTC arc-extinction device in the claim 1 to 5, it is characterized in that, described major loop sensing unit (2), control switch (3) and branch road sensing unit (5) are formed the double-current relay integral body of a special use, and wherein sensing unit (2) is a big current coil wherein; Sensing unit (5) is a little current coil wherein; Control switch (3) is the contact of double-current relay wherein.