CN205622217U - Switch tripping and closing return circuit protector - Google Patents

Abstract

The utility model provides a switch tripping and closing return circuit protector, including switch tripping and closing, rectifier diode, piezo -resistor and safeties, be provided with the positive terminal that is used for introducing direct current bus line, the negative pole end of introduction direct current negative busbar and the earthing terminal of introduction ground wire on the switch tripping and closing respectively, rectifier diode includes a rectifier diode and the 2nd rectifier diode, a rectifier diode's negative pole is connected to direct current bus line, and a rectifier diode's positive pole is connected to the ground wire, the 2nd rectifier diode's negative pole is connected to the ground wire, and the 2nd rectifier diode's positive pole is connected to the direct current negative busbar, piezo -resistor's both ends are on the electricity is connected to direct current bus line and direct current negative busbar respectively, just piezo -resistor with rectifier diode is parallelly connected, safeties with piezo -resistor establishes ties. The utility model discloses aim at solving the current vacuum contactor's of power plant tripping and closing owing to the cluster appears exchanging like the direct current, or the overtension leads to the problem of burning out.

Description

A kind of switch closing loop protector

Technical field

This utility model relates to a kind of switch closing loop protector.

Background technology

The breaker tripping and closing module of the 6KV F C vacuum contactor of power plant often occurs burning phenomenon, leads Cause F C vacuum contactor cannot normal divide-shut brake, there are major safety risks.The 6KV of power plant The power supply of the breaker tripping and closing module of F C vacuum contactor is 110V direct current, and analyzing on inspection is to jump to close Lock module has sealed in alternating component.Do not install due to power plant 6KV control dc bus and filter The device of alternating component, in alternating current seals in DC control circuit, will combine 6KV and protect Cause serious impact with the breaker tripping and closing module of 6KV vacuum contactor, even burn out vacuum and connect The breaker tripping and closing module of tentaculum.

Can cause in the middle of the AC in the DC loop protection exit auxiliary reclay malfunction or Cause the improper fusing of DC fuse thus cause the tripping of protection, straight-flow system is accessed Equipment also there is the biggest destruction.Meanwhile, the direct current that electric pressure is higher seals in grade In relatively low DC loop, cause low-voltage direct electricity consumption module to be burnt, equipment tripping or malfunction existing As happening occasionally.

Utility model content

Breaker tripping and closing for existing power plant vacuum contactor are owing to there is exchange string such as direct current or electric Pressing through the problem that height causes burning, this utility model provides a kind of switch closing loop protection Device, this switch closing loop protector, it is possible to effectively filter out the alternating component in DC loop, Realize overvoltage protection simultaneously, switch breaker tripping and closing are protected.

The technical scheme that the above-mentioned technical problem of this utility model solution is used is as follows:

There is provided one switch closing loop protector, including switch breaker tripping and closing, commutation diode, Varistor and safety, described switch breaker tripping and closing are separately provided for just introducing direct current The positive terminal of bus, the negative pole end introducing direct current negative busbar and the earth terminal of introducing ground wire；Described Commutation diode includes the first commutation diode and the second commutation diode, described first rectification two The negative pole of pole pipe is connected to direct current positive bus, and the positive pole of the first commutation diode is connected to ground wire； The negative pole of described second commutation diode is connected to ground wire, and the positive pole of the second commutation diode connects To direct current negative busbar；Being electrically connected to both ends of to direct current positive bus and direct current of described varistor In negative busbar, and described varistor is in parallel with described commutation diode, described safety with Described varistor is connected.

Further, described varistor include the first varistor, the second varistor, Three varistors and the 4th varistor, described first varistor and the series connection of the second varistor Between direct current positive bus and direct current negative busbar, described first varistor and the second varistor Intermediate connections be connected to ground wire；Described 3rd varistor and the 4th varistor are series at directly Between stream positive bus-bar and direct current negative busbar, in described 3rd varistor and the 4th varistor Between junction be connected to ground wire；Described first varistor, the series electrical of the second varistor composition Lu Yu tri-varistor, the series circuit parallel connection of the 4th varistor composition.

Further, described safety include temperature safety tube and power frequency electric fuse, described temperature Degree protective tube and power frequency electric fuse are all connected with described varistor.

This utility model is provided with loop protection device in the switch breaker tripping and closing of DC loop, by One commutation diode is arranged between direct current positive bus and ground wire, is arranged by the second commutation diode Between direct current negative busbar and ground wire, the first commutation diode and the second commutation diode are all anti- To cut-off, when there being alternating voltage to seal in DC loop, it is directly grounded by commutation diode, Cause the ac circuit sky sealed in start work, cut off the ac circuit sealed in；On the other hand, if Put varistor, according to Fuan characteristic of varistor, when voltage is relatively low, varistor Presenting the biggest resistance, leakage current is the least；After voltage raises and enters inelastic region, electric current exists In sizable scope during change, change in voltage is little, presents preferable pressure limiting characteristic；Voltage When raising, varistor enters saturation region, presents a linear resistance the least, thus right again Sensitive Apparatus is protected.

Accompanying drawing explanation

Fig. 1 is a kind of structural representation switching closing loop protector in this utility model.

Detailed description of the invention

In order to make this utility model be solved the technical problem that, technical scheme and beneficial effect more Clear, below in conjunction with drawings and Examples, this utility model is carried out the most specifically Bright.Should be appreciated that specific embodiment described herein only in order to explain this utility model, It is not used to limit this utility model.

See shown in accompanying drawing 1, the utility model discloses a kind of switch closing loop protector, Including switch breaker tripping and closing, commutation diode 5, varistor 1 and safety 6, described in open Close and in breaker tripping and closing, be separately provided for introducing the positive terminal 7 of direct current positive bus 2, introduce direct current The negative pole end 8 of negative busbar 4 and the earth terminal 9 of introducing ground wire 3；Described commutation diode 5 wraps Include the first commutation diode 51 and the second commutation diode 52, described first commutation diode 51 Negative pole be connected to direct current positive bus 2, the positive pole of the first commutation diode 51 is connected to ground wire 3； The negative pole of described second commutation diode 52 is connected to ground wire 3, the second commutation diode 52 Positive pole is connected to direct current negative busbar 4；Being electrically connected to both ends of to direct current of described varistor 1 On positive bus-bar 2 and direct current negative busbar 4, and described varistor 1 and described commutation diode 5 Parallel connection, described safety 6 are connected with described varistor 1.

Described varistor 1 includes first varistor the 11, second varistor the 12, the 3rd Varistor 13 and the 4th varistor 14, described first varistor 11 and second is pressure-sensitive Resistance 12 is series between direct current positive bus 2 and direct current negative busbar 4, described first pressure-sensitive electricity The intermediate connections of resistance 11 and the second varistor 12 is connected to ground wire 3；Described 3rd pressure-sensitive electricity Resistance 13 and the 4th varistor 14 are series between direct current positive bus 2 and direct current negative busbar 4, The intermediate connections of described 3rd varistor 13 and the 4th varistor 14 is connected to ground wire 3； The series circuit of described first varistor the 11, second varistor 12 composition and the 3rd pressure-sensitive The series circuit of resistance the 13, the 4th varistor 14 composition is in parallel, it should be noted that by In the existence of ground wire 3, during actual connection as shown in Figure 1.

Described safety 6 include temperature safety tube 61 and power frequency electric fuse 62, described temperature Protective tube 61 and power frequency electric fuse 62 are all connected with described varistor 1.

Electrical characteristic according to varistor 1, it is preferred to use by the varistor of zinc oxide material, It is similar to the characteristic that zinc oxide is lightning-arrest, when having outside Lightning Over-voltage or switching overvoltage Time, thunder and lightning and too high voltage just can be guided into the earth, thus be played protection by Zinc-Oxide Arrester The effect of electrical equipment, therefore two pin one ends of varistor 1 are connected on 6KV by the design The direct current positive bus 2 of the little bus of direct current, another pin is connected on the direct current of the little bus of 6KV direct current In negative busbar 4, it is DC110V according to dc bus normal voltage, it is considered to 6KV switch is jumped The protective effect of combined floodgate module and don't cause the malfunction of this protector, uses EPCOS to produce S14K150 varistor, its electric parameter is as follows: working volts alternating current (root-mean-square value) VRMS=150V, direct-current working volts VDC=200V, maximum surge current (peak point current) Imax (8/20 μ s)=6000A, ceiling capacity absorbs Wmax (2ms)=70J, varistor voltage VV (1mA)=240V, maximum clamper current potential VC, MAX (ic)=395V, clamp voltage electric current ic=50 A, commutation diode selection 1N4007, its main electrical parameters is as follows: maximum sustained peak is anti- To voltage: 1000V, maximum square voltage: 700V, maximum direct-current blocking-up voltage: 1000V, Maximum average rectified current (55 degree): 1A, maximum surge current (8.3ms is sinusoidal wave): 30A, Maximum forward voltage (direct current 1A): the 1.1V that continues, maximum direct current reverse current (in specified directly Flow resistance power-off is depressed): 5uA (25 degree), 500uA (100 degree), the most complete works of load is average Electric current: 30uA.

Bigger in view of nominal discharge current, therefore use the pressure-sensitive electricity of two same specifications and models Resistance carries out parallel connection, when using commutation diode 5 to seal in alternating current as the little bus of direct current simultaneously Protection, guides alternating current conducting ground wire into, thus plays protection 6KV and switch breaker tripping and closing module Effect.

In view of being typically short circuit when varistor punctures, in order to prevent hitting of varistor Wear and cause power supply short circuit on fire, a temperature safety tube of can connecting on each varistor 1 61 or hot releasing mechanisms.Temperature safety tube 61 should have good thermal coupling with varistor 1, When varistor 1 lost efficacy (high impedance short circuit), produced by it, heat is temperature safety tube 61 fusing, so that the varistor 1 lost efficacy separates with circuit, it is ensured that the safety of equipment. When higher power frequency temporary overvoltage acts on varistor 1, varistor 1 may be made Moment puncture short (low impedance short circuit), and temperature safety tube 61 also has little time fusing, also may be used Can be on fire.For avoiding this phenomenon to occur, it is considered to connect again on each varistor 1 one (alone power frequency electric fuse then may not melt impact-resistant power frequency electric fuse 62 when ageing failure Disconnected).The temperature safety tube that temperature safety tube 61 selects model to be SF91E, its electric parameter is Maximum voltage 250V, maximum current 15A, holding electric current 15A, operating temperature 94 ± 3/1 DEG C, In temperature-control range 94 DEG C.Power frequency electric fuse 62 uses the fastp-acting fuse that QH produces, maximum Voltage is 250V, maximum current 1515A, keeps electric current 15A.

The foregoing is only preferred embodiment of the present utility model, not in order to limit this reality With novel, all made within spirit of the present utility model and principle any amendment, equivalent replace Change and improvement etc., within should be included in protection domain of the present utility model.

Claims (3)

1. a switch closing loop protector, it is characterised in that include switching breaker tripping and closing, rectification two pole Pipe, varistor and safety, described switch breaker tripping and closing are separately provided for introduce direct current positive bus Positive terminal, introduce direct current negative busbar negative pole end and introduce ground wire earth terminal；Described commutation diode bag Including the first commutation diode and the second commutation diode, the negative pole of described first commutation diode is connected to direct current Positive bus-bar, the positive pole of the first commutation diode is connected to ground wire；The negative pole of described second commutation diode connects To ground wire, the positive pole of the second commutation diode is connected to direct current negative busbar；The two ends of described varistor are respectively It is electrically connected in direct current positive bus and direct current negative busbar, and described varistor is in parallel with described commutation diode, Described safety are connected with described varistor.

A kind of switch closing loop protector the most according to claim 1, it is characterised in that described Varistor includes the first varistor, the second varistor, the 3rd varistor and the 4th varistor, Described first varistor and the second varistor are series between direct current positive bus and direct current negative busbar, described The intermediate connections of the first varistor and the second varistor is connected to ground wire；Described 3rd varistor and Four varistors are series between direct current positive bus and direct current negative busbar, described 3rd varistor and the 4th pressure The intermediate connections of quick resistance is connected to ground wire；Described first varistor, the series connection of the second varistor composition The series circuit of circuit and the 3rd varistor, the 4th varistor composition is in parallel.

A kind of switch closing loop protector the most according to claim 1, it is characterised in that described Safety include that temperature safety tube and power frequency electric fuse, described temperature safety tube and power frequency electric fuse are all and institute State varistor series connection.