CN2503587Y

CN2503587Y - Multistep arc no-arc power-off DC power switch

Info

Publication number: CN2503587Y
Application number: CN 01233630
Authority: CN
Inventors: 王振民
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-08-03
Filing date: 2001-08-03
Publication date: 2002-07-31
Anticipated expiration: 2011-08-03

Abstract

The utility model provides a multistage arc extinguishing arc-free power breakdown direct current power switch which consists of contacts, a capacitor and a resistor. The capacity of the direct current arc-free power breakdown power switch is effectively reduced, thereby ensuring that the arc-free power breakdown of the high voltage heavy current direct current load is realized. The utility model can be widely applied to various direct current power electric power fields, and the utility model has extensive using prospect.

Description

Multistage extinguishing arc does not have electric arc outage direct current power switch

The utility model relates to a kind of direct current power switch.

The electric arc that when dc switch contact two ends shunt capacitor can be eliminated the switch outage, is produced.This method exists following problem: when bearing power was big, the required condenser capacity or the withstand voltage of capacitor increased thereupon.This not only makes the switch manufacturing cost increase, and the volume of switch also need increase.When electrical load power was increased to certain value, this extinguishing arc scheme became a unpractical problem.

At the problems referred to above, the utility model proposes a kind of multistage extinguishing arc that can realize that high power load does not have an electric arc outage does not have electric arc outage direct current power switch.

If switch is I by electric current, the instantaneous velocity that contact disconnects is V, the dielectric strength of contact place medium is P, contact shunt capacitor capacity is C, disconnect the electric current of carving inflow capacitor in the T very in short-term at contact and still be approximately I, the speed that contact separates still is V, and the electric field in supposition contact gap evenly distributes.Then:

The contact both end voltage is:

U＝IT/C

The contact gap critical voltage of discharge just is:

U _o＝PVT

Make U=U _o, promptly

IT/C＝PVT

That is:

C＝I/(PV) (1)

This shows that for fixing electric current I and definite medium (P fixes), the separating rate of required condenser capacity and switch contact is inversely proportional to.And the withstand voltage of capacitor is determined by power source voltage.The separating rate that improves switch contact can effectively reduce capacitor volume, but this speed brings up to certain limit and bring very big difficulty for the design of switch, also directly has influence on the mechanical endurance of switch simultaneously.The utility model proposes increases the quantity that switch divides breakpoint, suppose N branch breakpoint series connection arranged in circuit, each divides the contact separating rate of breakpoint all is V, when the disjunction simultaneously of N branch breakpoint, then the total points of switch is NV from speed, wherein N is the quantity that switch divides breakpoint, so just can reduce N to condenser capacity doubly.Be difficult to accomplish but in fact allow the strictness of N branch breakpoint separate simultaneously, so early divide the breakpoint place still can produce electric arc.If dividing the shunt capacitor C respectively of breakpoint place, and satisfy (1) formula, no matter these minutes breakpoint disjunction whether simultaneously strict, can both strictness accomplish not have the arc outage.Although each condenser capacity all is C, as long as take certain measure, for example, give each capacitor balance resistance in parallel or piezo-resistance, its withstand voltage just can be reduced to the 1/N of supply voltage.This has been equivalent to reduce total capacitor volume (single breakpoint situation of dividing needs N such capacitor).

Above-mentioned multistage extinguishing arc scheme can also further expand, in the power process, voltage rising along with the capacitor charging, the voltage of load reduces gradually, the electric current of circuit is decayed in time, if being set, above-mentioned switch divide the breakpoint disjunction to be certain order, circuital current is little during the branch breakpoint disjunction of the disjunction relatively early of the circuital current during the branch breakpoint disjunction of later disjunction, thereby the capacitor volume of these minutes breakpoint place parallel connection can be successively decreased according to the disjunction order that divides breakpoint, excessive in order to be unlikely the capacitor charging, every grade of capacitor needs piezo-resistance deboost in parallel, can further reduce the total capacity of capacitor so again.

Therefore, basic design of the present utility model is as follows:

A, a plurality of minutes breakpoints 2 series connection backs by auxiliary normally open contact 6 be parallel to main contact 1 two ends (Fig. 1,2,4,5) that connect power supply and load or B, a plurality of minutes breakpoint 2 series connection backs directly are connected power supply and load (Fig. 3,6,7,8); Corresponding each branch breakpoint 2 shunt capacitor 3, balance resistance 4 in parallel again or piezo-resistance 9 (resistance and piezo-resistance can be used separately, also can use simultaneously); All divide the disjunction of breakpoint 2 also can be certain definite sequence for simultaneously; For situation A, each moment of dividing breakpoint 2 to disconnect all lags behind the disjunction moment of main contact 1, and the closure of normally open contact 6 lags behind the closing moment of main contact 1, disconnects lagging behind any one disjunction that divides breakpoint 2 constantly; Be series in the connecting circuit of circuit that electric capacity 3 and balance resistance 4 or piezo-resistance 9 constitute and main circuit (Fig. 3,6,7,8) disconnection of normally open contact 6 and closedly lag behind disconnection and the closure that each divides breakpoint 2 respectively for case B normally open contact 6; Discharge circuit can be made of dual mode: 1, the circuit (Fig. 1,3,4,5,6,7,8) that is made of discharge resistance 5 and normally closed interlock 7 series connection in all circuit two ends parallel connections that divide breakpoint, balance resistance, piezo-resistance to constitute; 2, the series circuit (Fig. 2) that constitutes by discharge resistance 5 and normally open contact 12 in normally open contact 6 two ends parallel connections, the closure of the closed leading normally open contact 6 of normally open contact 12; Fly-wheel diode 8 is parallel to the load two ends, and wherein the positive pole of fly-wheel diode connects the negative pole end of power supply, the positive terminal (Fig. 1～8) that negative pole connects power supply.

Above-mentioned A situation circuit working process is as follows: had no progeny in 1 minute when main contact, electric current is flow through by the series circuit of minute breakpoint 2, and the main contact gap obviously can not produce electric arc.When 2 disjunctions of minute breakpoint, each divide breakpoint two ends all in parallel capacitor 3, capacitor selects to satisfy the requirement of (1) formula, thereby divides the breakpoint gap can not produce electric arc, but the withstand voltage of electric capacity is reduced to the 1/N of supply voltage.The voltage of all electric capacity 3 is basic identical with constantly when disjunction is basic, and the capacitor of higher voltage is by balance resistance 4 balance or released by piezo-resistance 9 gradually.When a minute breakpoint disjunction became a graded, piezo-resistance 9 had limited the magnitude of voltage with its shunt capacitance.The capacitor volume of separating later branch breakpoint parallel connection can be less than the capacitor volume of separating branch breakpoint parallel connection early, and this just makes switch additional capacitors amount further reduce.Said circumstances B circuit is directly cut off the power supply by minute breakpoint 2, and the circuit of process and situation A is basic identical, repeats no more.

Double break contact often is used in power switch, this contact has two branch breakpoints, when the branch breakpoint of this contact and capacitor 3, balance resistance 4 or piezo-resistance 9 are connected in parallel, connection between the mobile that moving contact is connected and these components and parts can be that fexible conductor 14 can not disjunction connection (Fig. 4,6,8), also can on movable body that moving contact is connected and Switch main body dynamic and static contact 15 be set again and realize (Fig. 5,7); The contact of dynamic and static contact 15 is an Elastic Contact, in separation process this to the segregation lag of contact in the separation of two branch breakpoints 2 of this double break contact.

Below be to adopt double break contact realization two-stage extinguishing arc not have the embodiment of electric arc outage direct current power switch: as shown in Figure 8, double break contact 13 connects power supply and load, shunt capacitor 3 between 13 two branch breakpoint 2 moving contacts of double break contact and fixed contact, balance resistance 4 in parallel again or piezo-resistance 9; This parallel connection and moving contact being connected of mobile that be connected can be that fexible conductor 14 can not the disjunction connection, also can on movable body that moving contact is connected and Switch main body dynamic and static contact be set again and realize; The contact of dynamic and static contact is an Elastic Contact, in separation process this to the segregation lag of contact in the separation of two branch breakpoints 2; Be parallel to double break contact 13 two ends after 7 series connection of discharge resistance 5 and normally closed interlock, normally open contact 6 is series in the connecting circuit of circuit that capacitor 3, balance resistance 4, piezo-resistance 9, discharge resistance 5 and normally closed interlock 7 constitute and main circuit; The disconnection of normally open contact 6 and closed disconnection and the closure that lags behind each branch breakpoint 2 respectively; Fly-wheel diode 8 is parallel to the load two ends, and wherein the positive pole of this diode connects the negative pole end of power supply, the positive terminal that negative pole connects power supply.

Description of drawings is as follows: Fig. 1,2, the 3rd, and the utility model circuit theory diagrams, Fig. 1, the 2nd wherein connects power supply with load but adopted two different discharge circuits by main contact 1, and Fig. 3 directly connects power supply and load by a plurality of minutes breakpoint series connection backs.Fig. 4,5,6, the 7th adopts the multistage extinguishing arc of double break contact not have electric arc outage direct current power switching circuit structure chart.Fig. 8 adopts double break contact realization two-stage extinguishing arc not have electric arc outage direct current power switching circuit structure chart.In these figure, the 1st, the main contact of connection power supply and load, the 2nd, minute breakpoint, the 3rd, capacitor, the 4th, balance resistance, the 5th, discharge resistance, the 6th, normally open contact, the 7th, normally closed interlock, the 8th, fly-wheel diode, the 9th, piezo-resistance, the 12nd, normally open contact, the 13rd, double break contact, the 14th, fexible conductor, the 15th, the dynamic and static contact that is provided with on movable body that moving contact is connected and the Switch main body.

The utility model adopts the method for multistage breakpoint and Capacitance parallel connection to eliminate the electric arc of direct current power switch, has Effect ground has reduced the capacity of required capacitor, becomes thereby make the high-voltage large current DC load not have the electric arc outage Reality. The utility model can be widely used in various direct current powers field, and wide prospect of the application is arranged.

Claims

1, a kind of multistage extinguishing arc that comprises that contact, capacitor, resistance constitute does not have electric arc outage direct current power switch, is primarily characterized in that: A, a plurality of minutes breakpoint (2) series connection backs directly are connected power supply and load after being parallel to main contact (1) two ends that connect power supply and load or B, the series connection of a plurality of minutes breakpoints (2) by auxiliary normally open contact (6); Corresponding each branch breakpoint (2) shunt capacitor (3), balance resistance in parallel again (4) or piezo-resistance (9) (resistance and piezo-resistance can be used separately, also can use simultaneously); All divide the disjunction of breakpoint (2) also can be certain definite sequence for simultaneously; For situation A, each moment of dividing breakpoint (2) to disconnect all lags behind the disjunction moment of main contact (1), and the closure of normally open contact (6) lags behind the closing moment of main contact (1), disconnects lagging behind any one disjunction that divides breakpoint (2) constantly; Be series at for case B normally open contact (6) in the connecting circuit of circuit that electric capacity (3) and balance resistance (4) or piezo-resistance (9) constitute and main circuit, the disconnection of normally open contact (6) and closure lag behind each disconnection and the closure of dividing breakpoint (2) respectively; Discharge circuit can be made of dual mode: 1, the circuit that is made of discharge resistance (5) and normally closed interlock (7) series connection in all circuit two ends parallel connections that divide breakpoint, balance resistance, piezo-resistance to constitute; 2, the series circuit that constitutes by discharge resistance (5) and normally open contact (12) in normally open contact (6) two ends parallel connection, the closure of the closed leading normally open contact (6) of normally open contact (12); Fly-wheel diode (8) is parallel to the load two ends, and wherein the positive pole of fly-wheel diode connects the negative pole end of power supply, the positive terminal that negative pole connects power supply.

2, there is not electric arc outage direct current power switch according to right 1 described multistage extinguishing arc, be primarily characterized in that: do not have electric arc outage direct current power switch by the multistage extinguishing arc that the branch breakpoint of double break contact constitutes, the breakpoint of this contact and capacitor (3), balance resistance (4) or piezo-resistance (9) are when being connected in parallel, connection between the mobile that moving contact is connected and these components and parts can be that fexible conductor (14) can not the disjunction connection, also can on movable body that moving contact is connected and Switch main body dynamic and static contact (15) be set again and realize; The contact of dynamic and static contact (15) is an Elastic Contact, in separation process this to the segregation lag of contact in the separation of two branch breakpoints (2) of this double break contact.

3, there is not electric arc outage direct current power switch according to right 1 described multistage extinguishing arc, be primarily characterized in that: adopt double break contact realization two-stage extinguishing arc not have electric arc outage direct current power switch, double break contact (13) connects power supply and load, shunt capacitor (3) between (13) two branch breakpoint (2) moving contacts of double break contact and fixed contact, balance resistance in parallel again (4) or piezo-resistance (9); This parallel connection and moving contact being connected of mobile that be connected can be that fexible conductor (14) can not the disjunction connection; Also can on movable body that moving contact is connected and Switch main body, dynamic and static contact be set again and realize that the contact of dynamic and static contact is an Elastic Contact, in separation process this to the segregation lag of contact in the separation of two branch breakpoints (2); Be parallel to double break contact (13) two ends after the series connection of discharge resistance (5) and normally closed interlock (7), normally open contact (6) is series in the connecting circuit of the circuit of capacitor (3), balance resistance (4), piezo-resistance (9), discharge resistance (5) and normally closed interlock (7) formation and main circuit; The disconnection of normally open contact (6) and closure lag behind each disconnection and the closure of dividing breakpoint (2) respectively; Fly-wheel diode (8) is parallel to the load two ends, and wherein the positive pole of this diode connects the negative pole end of power supply, the positive terminal that negative pole connects power supply.