CN202424110U

CN202424110U - High-capacity fast switching device

Info

Publication number: CN202424110U
Application number: CN2011204540585U
Authority: CN
Inventors: 施守文
Original assignee: ANHUI MAN RUITE ELECTRIC Co Ltd
Current assignee: ANHUI MAN RUITE ELECTRIC Co Ltd
Priority date: 2011-11-16
Filing date: 2011-11-16
Publication date: 2012-09-05
Anticipated expiration: 2021-11-16

Abstract

The utility model relates to a high-capacity fast switching device. The device comprises a fuse, a current mutual inductor electrically connected with the fuse, a measurement and control unit electrically connected with the current mutual inductor, a bridge body electrically connected with the measurement and control unit, and a nonlinear resistor connected in parallel to the fuse; and the bridge body is connected in parallel with the fuse. The high-capacity fast switching device has the advantages that the speed mobility is improved by more than 20 times; a rate of change of current is added for judging; the design is reasonable, and the reliability is high; switching on/off capacity cannot be restricted; expectant impact current of a system can never be reached; no hazardous voltage exist during a switching on/off process, and system investment is greatly lowered.

Description

A kind of big capacity fast-switching arrangement

Technical field

The utility model relates to a kind of switching device, relates in particular to a kind of big capacity fast-switching arrangement.

Background technology

Along with the fast development of China's distribution network, the capacity of short circuit of electric power system increases day by day, and the excitation of generator outlet end becomes, unit transformer, and short circuit current is very big, and the past, conventional way was: the mode of cut-offfing that adopts circuit breaker series connection current limiting reactor.When electrical network during in normal operation, there are voltage landing and loss, very big to the transmission of electricity quality influence of electrical network.Reactor can only change the peak value of short circuit current and can not change time of short circuit current zero crossing, and circuit breaker will just can cut-off short circuit current in several again cycles, and the peak value of short circuit current causes cumulative bad to destroy repeatedly through short-circuit network to system.Special city's generator outlet short circuit; Short circuit current will pass through the time that reaches 20ms ~ 150ms could zero crossing, makes circuit breaker cut-off difficulty, and switch off time is long; To generator; Transformer and cable produce very big electric power and thermal effect effect, produce very big repulsion electric power on the switch contact, make contact that burnout failure often take place.

The utility model content

In view of this, be necessary to provide a kind of big capacity fast-switching arrangement, be intended to protect fast and effectively power consumption equipment,, improve the power supplying efficiency of electrical network, enlarging of minimizing system or the needed investment of networking operation like high-rating generator.

The utility model is to realize like this; A kind of big capacity fast-switching arrangement; The current transformer that it comprises fuse, electrically connect with said fuse, the measurement and control unit that electrically connects with said current transformer, the pontic that electrically connects with said measurement and control unit and be connected in parallel on the nonlinear resistance on the said fuse, said pontic is also parallelly connected with said fuse.

The beneficial effect of the big capacity fast-switching arrangement of the utility model is: the raising of quick-action property is more than 20 times; Increasing current changing rate judges; Reasonable in design, reliability is higher; Cut-offfing capacity can be unrestricted; System does not reach the impulse current of expection forever; No harmfulness voltage in the interrupting process; System's investment reduces greatly.

Description of drawings

The circuit theory diagrams of the big capacity fast-switching arrangement that Fig. 1 provides for the utility model preferred embodiments.

Fig. 2 is the current characteristics sketch map of big capacity fast-switching arrangement among Fig. 1.

Fig. 3 a and Fig. 3 b are the application sketch map of big capacity fast-switching arrangement among Fig. 1.

Fig. 4 a and Fig. 4 b are the Another Application sketch map of big capacity fast-switching arrangement among Fig. 1.

Fig. 5 a and Fig. 5 b are the another application sketch map of big capacity fast-switching arrangement among Fig. 1.

Fig. 6 is an application sketch map again of big capacity fast-switching arrangement among Fig. 1.

Symbol description

Big capacity fast-switching arrangement 100

Fuse F U

Current transformer CT

Measurement and control unit 10

Pontic FS

Nonlinear resistance FR

Generator G

Embodiment

For the purpose, technical scheme and the advantage that make the utility model is clearer,, the utility model is further elaborated below in conjunction with accompanying drawing and embodiment.Should be appreciated that specific embodiment described herein only in order to explanation the utility model, and be not used in qualification the utility model.

See also Fig. 1; The circuit theory diagrams of the big capacity fast-switching arrangement (FSR) 100 that it provides for the utility model preferred embodiments; The current transformer CT that it comprises fuse F U, electrically connect with fuse F U, the measurement and control unit 10 that electrically connects with current transformer CT, the pontic FS that electrically connects with measurement and control unit 10 and be connected in parallel on the nonlinear resistance FR on the fuse F U, pontic FS is also parallelly connected with fuse F U.

Pontic FS, it just often flows through operating current, within 0.15ms, breaks off fast during short circuit.Fuse F U, its pontic FS break off the back all short circuit currents transfer to fuse F U, with interior fusing, and produce enough arc voltages at 0.5ms.Nonlinear resistance FR, its arc voltage that when fuse F U fuses, produces makes its conducting, absorbs magnetic energy, and the overvoltage Limiting when cut-offfing is in allowed band.Current transformer CT is under failure condition, and current signal is undistorted, do not lag behind.Measurement and control unit 10 detects electric current and current changing rate, sends breaking signal to pontic when fault occurs.Novel principle, advanced technology, design makes high capacity and high speed switchgears 100 compare with the protected mode that conventional circuit breaker adds relay cleverly, has more unique advantages.

Big capacity fast-switching arrangement 100 has following characteristic:

The raising of quick-action property is more than 20 times, and fault current is dammed within 1ms, decays to 0 within the 3ms, and fault is by excision fully, and circuit breaker adds the protected mode of relay and wants 60ms could excise fault (as shown in Figure 2) at least;

Increase current changing rate and judge that sensitivity is higher, the current changing rate increase is more obvious during fault;

Reasonable in design, reliability is higher, when current amplitude and current changing rate surpass normal value simultaneously, is judged as generations of opening circuit, and adopts three identical observing and controlling parts that work alone, and with " voting formula " judgement, sends breaking signal, can not judge by accident disconnected;

Cut-offfing capacity can be unrestricted; Running current passes through from pontic FS; The arc voltage that the fuse F U of high rupturing capacity produces is enough to make nonlinear resistance FR conducting; Nonlinear resistance FR conducting makes the reliable blow-out of fuse F U, as long as the corresponding nonlinear resistance FR of configuration absorbs magnetic energy, cut-offs capacity and just possibly get enough big;

System does not reach the impulse current of expection forever; Fault current is promptly blocked with interior at 1ms; Subtract gradually afterwards decline to 0. shut off value 1p be merely expection opening amperage Imax about 1/10th; The electric power that system bears significantly reduces, and the I2t that is passed through is merely several one thousandths that circuit breaker cut-offs mode;

No harmfulness voltage in the interrupting process, znr FR with overvoltage Limiting in 2.5 times of specified phase voltages of national Specification;

System investment reduces greatly, and power equipment can be avoided the impact of powerful breaking current, and mechanical strength needn't design very greatly, cut-offs soon, holds back for a short time, and power equipment need not be considered thermally-stabilised problem, and conductor size needn't be very big.

Please consult Fig. 3 a and Fig. 3 b in the lump, it is applied to the sketch map of high-rating generator for big capacity fast-switching arrangement 100.High-rating generator G outlet is opened circuit and can be obtained fast effectively protection, and it is big to cut-off capacity, is the equipment that cut-offs that generator G outlet and station-service divide component ideal, makes generator G, transformer obtain fast effectively protection.

Please consult Fig. 4 a and Fig. 4 b in the lump, it is applied to the sketch map of system's enlarging or networking for big capacity fast-switching arrangement 100.Significantly reduce the investment of system's enlarging or the required usefulness of networking operation, big capacity fast-switching arrangement 100 is fast with system splitting during short circuit, and the load side circuit breaker is only selected by the breaking current that separate unit power transformation device provides.Original switchgear needn't be changed when system extended.Can improve system's power supply reliability, the pressure drop when reducing the heavy duty startup realizes economical operation.

Please consult Fig. 5 a and Fig. 5 b in the lump, it is the application sketch map that big capacity fast-switching arrangement 100 combines with reactor.Big capacity fast-switching arrangement 100 is parallelly connected with reactor to be most economical effective current limliting scheme, when normally moving big capacity fast-switching arrangement 100 with the reactor short circuit, the voltage drop when having avoided the startup of huge electric energy loss of reactor and high capacity motor.Big capacity fast-switching arrangement 100 breaks off fast during short circuit, and the drop-out current of load side circuit breaker receives reactor to be restricted to allowed band.When new electricity supplying and using system designs, can strengthen the reactor impedance, the drop-out current of load side circuit breaker is further reduced, reduce cost.

See also Fig. 6, it is the application sketch map that big capacity fast-switching arrangement 100 combines with important load.Big 100 pairs of capacity fast-switching arrangements do not allow the instantaneous interruptedly supplying power or the important load of self-starting by force, can improve power supply quality.During line short, big capacity fast-switching arrangement 100 breaks off fast, and with the reactor input, the residual voltage on the reactor can design to such an extent that be enough to keep that important load continues to move and unaffected.

The above is merely the preferred embodiment of the utility model; Not in order to restriction the utility model; Any modification of being done within all spirit and principles at the utility model, be equal to replacement and improvement etc., all should be included within the protection range of the utility model.

Claims

1. one kind big capacity fast-switching arrangement; It is characterized in that; The current transformer that it comprises fuse, electrically connect with said fuse, the measurement and control unit that electrically connects with said current transformer, the pontic that electrically connects with said measurement and control unit and be connected in parallel on the nonlinear resistance on the said fuse, said pontic is also parallelly connected with said fuse.