CN202435028U

CN202435028U - Automatic-access-type double-loop resistance-capacitance absorber

Info

Publication number: CN202435028U
Application number: CN2012200416121U
Authority: CN
Inventors: 赵章开
Original assignee: ZHEJIANG ZHONGNENG ELECTRICAL CO Ltd
Current assignee: ZHEJIANG ZHONGNENG ELECTRICAL CO Ltd
Priority date: 2012-02-09
Filing date: 2012-02-09
Publication date: 2012-09-12
Anticipated expiration: 2022-02-09

Abstract

The utility model relates to an overvoltage protection device of a power system and discloses an automatic-access-type double-loop resistance-capacitance absorber capable of attenuating and eliminating open circuit. The automatic-access-type double-loop resistance-capacitance absorber comprises four resistance-capacitance absorber units. One ends of the resistance-capacitance absorber units are interconnected together to form a neutral point O. The other ends of the resistance-capacitance absorber units are respectively connected to an A-phase line, a B-phase line, a C-phase line and a ground line D of protected equipment. The automatic-access-type double-loop resistance-capacitance absorber has the advantages that the capacitive current of the system is not increased, the harmonic interference is resisted, the energy is saved, the protection between phases as well as between the phase and the ground can be simultaneously realized, the resistance-capacitance absorber can be connected with a combined lightning arrester in parallel for use and the protection effect is better.

Description

Automatic access type double loop rc absorber

Technical field

The utility model relates to the overvoltage protection of electric power system; Be specifically related to a kind of decay and eliminate circuit breaker; As: vacuum circuit-breaker, contactor etc.; Cut-off inductive load equipment, as: the higher-order of oscillation overvoltage that motor, generator, transformer etc. are produced is brought the automatic access type double loop rc absorber with over-voltage protection function of very big harm.

Background technology

Along with the extensive use of vacuum circuit-breaker, the overvoltage accident that produces when being operated by vacuum circuit-breaker also constantly takes place.Especially cut-off the inductive load electric equipment during vacuum circuit-breaker operation; As: motor, generator, transformer, reactor etc.; The cut-off overvoltage that is produced, repeatedly restrike overvoltage, three-phase cut-offs overvoltage simultaneously, all has characteristics of high-frequency, high steepness, amplitude, and this higher-order of oscillation overvoltage is big to the insulation harmfulness of electric equipment; Simple is not enough with outstanding zinc oxide arrester protection; Because zinc oxide arrester can only over-voltage amplitude, and slow to the response speed of frequency, be unable to catch up with the pace of change of higher-order of oscillation frequency; And rc absorber or be the capacitance-resistance overvoltage protection device, in the characteristics that just have distinctive feature aspect the attenuate high frequency frequency of oscillation.

There is drawback in rc absorber product of the prior art: a kind of is the rc absorber of traditional type; Adopt oil immersed type capacitors in series metal linear resistance; Volume is big, and the trouble of leakage of oil is arranged, in case the fire hazardous that has an accident; And the no oiling of high voltage distribution installation requires not allow three oil filled capacitors are installed in every switch cubicle, also just do not fit into to be contained in the switch cubicle.Another kind is to make with the polypropylene metallic film, and embedding flame retardant epoxy, shell are the ZR type dry type rc absorber that DMC suppresses the high pressure self healing capacitor series connection metal linear resistance that forms, because China's economy grows continuously and fast; Converter, arc furnace, railway, subway, light rail, household electrical appliances, IT or the like, the rectifying installation that every profession and trade is used is increasing, and each the order harmonic wave that is produced pours in; Severe contamination electrical network, harmonic wave acts on the rc absorber product, will cause the harmonic wave overvoltage; Be the every rising 10% of voltage, life of capacitors approximately shortens closely partly, overcurrent, promptly causes heating; It is generally acknowledged 8 ℃ of the every risings of temperature, its life-span also shortens more than half, the added burden of overload superposition in product work, causes that partial discharge of capacitor intensity increases; Ageing of insulation, the product abnormal heating, resistance also often burns out; Can also cause that pole plate mechanical resonant or pole plate elastic vibration cause damage of product, shorten the life-span, often have explosion accident to take place.

Also having a kind of is the rc absorber that has series gap, is the measure of taking to solving the harmonic pollution electrical network.During operate as normal, the gap does not puncture, and separates power supply, in order to avoid the invasion of high order harmonic component, and saves energy.Problem is, the introducing in gap, and its discharge voltage is dispersed big, and is subject to environmental condition, and like influences such as temperature, humidity, height above sea levels, if improper use, the gap burns out has extinguished not electric arc, is prone to cause the product blast.

A noticeable key factor is: with the rc absorber of metal linear resistance series capacitor composition; Usually 0.1 μ F is held in power taking, resistance 100 Ω, and capacitor value is much larger than resistance value; It is installed between phase line and the earth, the capacitance current value in the time of can increasing single-phase earthing undoubtedly.China 66kV and following electric power system are isolated neutral system, the regulation 2h that can operate with failure, and generally single-phase-to-ground current can not surpass 10A.If 30 groups of RC rc absorber protective devices are housed in the 6kV system, then only the capacitance current of RC protective device generation just reaches 10.8A, adds that China's urban network restructuring cable line increases day by day; Take into account the electric capacity of electric equipments such as cable again, the electric current of single-phase earthing can reach more than the 15A, as far as the power plant; This value will cause this system's feeding circuit all to trip; Cause the large tracts of land loss of power accident, and have a strong impact on the normal operation of generator, can't ignore this.

Summary of the invention

The purpose of the utility model is to overcome above-mentioned shortcoming of the prior art, provide a kind of do not increase system capacitance property electric current, anti-Harmonic Interference, energy-conservation, can be simultaneously between phase and phase and and ground between the automatic access type double loop rc absorber protected.

In order to solve the problems of the technologies described above, the utility model is able to solve through following technical proposals:

Automatic access type double loop rc absorber; Comprise four rc absorber unit; One end of described every rc absorber unit interconnects and is that neutral point O, the other end then are connected to by on A phase line, B phase line, C phase line and the ground wire D of protection equipment.

As preferably, described rc absorber unit comprises resistor and the capacitor that is connected in series.

As preferably, an end of described rc absorber unit I is connected in neutral point O, and the other end is connected in by the A phase line of protection equipment; One end of rc absorber unit II is connected in neutral point O, and the other end is connected in by the B phase line of protection equipment; One end of rc absorber unit III is connected in neutral point O, and the other end is connected in by the C phase line of protection equipment; One end of rc absorber unit IV is connected in neutral point O, and the other end is connected in by the D phase line of protection equipment.

As preferably, described resistor is non-linear zinc oxide resistance sheet.

As preferably, described capacitor is the high pressure dry capacitor.

As preferably, described resistor and capacitor are sealed in insulation crust and the silastic material.

The utility model is owing to adopted above technical scheme; Have significant technique effect: the utility model do not increase system capacitance property electric current, anti-Harmonic Interference, energy-conservation, can be simultaneously between phase and phase and and ground between protect; Parallelly connected use with combined arrester simultaneously, the protection effect is better.

Description of drawings

Fig. 1 is the structural representation of the utility model embodiment 1.

Fig. 2 is the non-linear voltage-current characteristic sketch map of controllable resistor R.

The toponym that each number designation referred in the above accompanying drawing is following: wherein 1-rc absorber unit I, 2-rc absorber unit II, 3-rc absorber unit III, 4-rc absorber unit IV, 5-resistor, 6-capacitor.

Embodiment

Below in conjunction with accompanying drawing 1,2 and embodiment the utility model is described in further detail:

Embodiment 1

Automatic access type double loop rc absorber; Like Fig. 1, shown in 2; Comprise four rc absorber unit, an end of described every rc absorber unit interconnects and is that neutral point O, the other end then are connected to by on A phase line, B phase line, C phase line and the ground wire D of protection equipment.Among the figure: A, B, C, D; Be respectively by A phase line, B phase line, C phase line and the ground wire of protection equipment; 1, be the rc absorber unit in 2,3,4 frame of broken lines, a branch road is formed in every unit, and O is the common point that links together or the neutral point of four branch roads; Its other end is connected to by on A phase line, B phase line C phase line and the ground wire D of protection equipment, and wherein: AOD, BOD, COD constitute the protection relatively of A phase, B phase, C phase respectively; AOB, BOC, AOC constitute the protection that AB is alternate, BC is alternate and AC is alternate respectively.Rc absorber is a three-phase and quadrupole formula structure, and integral arrangement is directly perceived, attractive in appearance, light and handy, firm, be convenient to install, not only protected the overvoltage between phase and phase but also protect and ground between overvoltage to the harm of equipment.Because the utility model autocontrol inserts electrical network automatically, operation voltage is stable, and is dispersed little, energy-conservation.

The rc absorber unit comprises the resistor 5 and capacitor 6 that is connected in series.Said rc absorber unit is connected in series by controllable resistor 5, capacitor 6, is used for changing the operating state of circuit, with higher-order of oscillation process strong attenuation, the frequency of oscillating circuit and steepness is reduced greatly.

One end of rc absorber unit I 1 is connected in neutral point O, and the other end is connected in by the A phase line of protection equipment; One end of rc absorber unit II 2 is connected in neutral point O, and the other end is connected in by the B phase line of protection equipment; One end of rc absorber unit III 3 is connected in neutral point O, and the other end is connected in by the C phase line of protection equipment; One end of rc absorber unit IV 4 is connected in neutral point O, and the other end is connected in by the D phase line of protection equipment.

Resistor 5 is non-linear zinc oxide resistance sheet.Said resistor 5 is to be primary raw material with zinc oxide (ZnO); Add bismuth oxide (Bi2O3), cobalt oxide (Co2O3), manganese oxide (MnO2), chromium oxide (Cr2O3), antimony oxide (Sb2O3), the silica raw materials such as (SiO2) of trace; Burn till → grind → non-linear zinc oxide resistance sheet that heat treatment → multiple working procedures such as aluminium spraying electrode form through ball mill grinding → mixing → mist projection granulating → moisture → press forming → go bond → high temperature, the multi-disc superposition is neat, twines, forms with flame-proof silicon rubber material monolithic molded vulcanization shaping overcoat behind the curable epoxide with the expoxy glass silk ribbon again; Has excellent non-linear voltage-current characteristic; Resistance is very big under the little electric current, is equivalent to insulator, in case will conducting become conductor when reaching a certain voltage; Its resistance is inversely proportional to electric current again under this state; Along with the increase resistance value of electric current diminishes thereupon, so electric current increases, ohmically pressure drop is risen very little.Resistive element adopts the znr of non-linear excellence, and during the system operate as normal, it is equivalent to insulator, and rc absorber and system are isolated, and promptly capacitor does not insert electrical network; When having served as voltage magnitude and reaching a certain set point, because its resistance of nonlinear characteristic of resistance diminishes, rc absorber inserts electrical network automatically, brings into play its protective effect.Therefore its distinguishing feature is: even 1. many uses can not increase the ground capacity property electric current of electrical network yet; 2. under system's normal operation, the electric current that flows through rc absorber is minimum, is not more than 20mA, saves the energy; 3. under the normal operating conditions, owing to be in series with the effect of nonlinear resistance, reduce the invasion of harmonic wave, and the voltage that bears on the capacitor is very little, load is light, and the thermal effect on the rc absorber is improved greatly.

Capacitor 6 is the high pressure dry capacitor.Said capacitor 6 is a dielectric for the high-quality high-performance poly third dilute metal film, and the high pressure dry capacitor with the flame retardant epoxy embedding forms is characterized in that: electric strength is high, and has self-healing function.Totally-enclosed, all insulation structure that Resistor-Capacitor Unit is designed to, sealing property is excellent.

Big (the big 5kj/kV of thermal capacity～6kj/kV), be tens times of general rc absorber linear resistance thermal capacity of nonlinear resistance discharge capacity.Product is applicable in the cabinet and uses, and absorbs the higher-order of oscillation overvoltage that produces when vacuum switch or circuit breaker cut-off, and can not be used for lightning protection, can not be used for long-time absorption system high order harmonic component.Parallelly connected use with combined arrester, the protection effect is better.

Resistor 5 is sealed in insulation crust and the silastic material with capacitor 6.Resistance, capacity cell are sealed in insulation crust and the silastic material, and be fire-retardant, explosion-proof performance good.

Resistor 5 is a controllable resistor, and its non-linear voltage-current characteristic is referring to Fig. 2; Under the normal operation, shown in V2 among Fig. 2, this moment, the resistance of resistor 5 was very big; The electric current that is flow through has only several microamperes, is equivalent to the insulator crosscut between the phase line and capacitor 6 of electrical network, that is to say that rc absorber does not insert network system; Consumed power does not provide capacitance current to system yet; When overvoltage intrusion and amplitude arrival V1 value (flex point of VA characteristic curve), resistor 5 beginning conductings, this is called the origination action voltage of rc absorber; Rc absorber inserts network system automatically; And when overvoltage surpasses V1, then getting into the smooth stage of non-linear resistance VA characteristic curve, resistor 5 becomes conductor; Rc absorber is very rapidly brought into play the effect of damped oscillation and attenuated oscillation frequency; The superpotential frequency decay of the higher-order of oscillation is slowly got off, and its overvoltage amplitude also will reduce greatly, protect by the insulation of protection equipment and avoid the superpotential damage of the higher-order of oscillation.After overvoltage was gone over, controllable resistor or resistor 5 recovered state of insulation again, and system restoration normally moves.Visible by resistor among Fig. 25 or the non-linear VA characteristic curve of controllable resistor R; Representing the operating current value that produces under the switching overvoltage in the curve flat portions; This stage, its ohmically voltage drop increased little, helps giving full play to the effect of rc absorber along with the increase of current value.The origination action voltage of preferred variable resistor R and excellent voltage-current characteristic thereof to control its resistance value, can obtain the good heat balance effect of rc absorber.

In a word, the above is merely the preferred embodiment of the utility model, and all equalizations of being done according to the utility model claim change and modify, and all should belong to the covering scope of the utility model patent.

Claims

1. automatic access type double loop rc absorber; Comprise four rc absorber unit; It is characterized in that: an end of described every rc absorber unit interconnects and is that neutral point O, the other end then are connected to by on A phase line, B phase line, C phase line and the ground wire D of protection equipment.

2. automatic access type according to claim 1 double loop rc absorber is characterized in that: described rc absorber unit comprises the resistor (5) and capacitor (6) that is connected in series.

3. automatic access type according to claim 1 double loop rc absorber, it is characterized in that: an end of described rc absorber unit I (1) is connected in neutral point O, and the other end is connected in by the A phase line of protection equipment; One end of rc absorber unit II (2) is connected in neutral point O, and the other end is connected in by the B phase line of protection equipment; One end of rc absorber unit III (3) is connected in neutral point O, and the other end is connected in by the C phase line of protection equipment; One end of rc absorber unit IV (4) is connected in neutral point O, and the other end is connected in by the D phase line of protection equipment.

4. automatic access type according to claim 2 double loop rc absorber is characterized in that: described resistor (5) is non-linear zinc oxide resistance sheet.

5. automatic access type according to claim 2 double loop rc absorber is characterized in that: described capacitor (6) is the high pressure dry capacitor.

6. automatic access type according to claim 2 double loop rc absorber is characterized in that: described resistor (5) is sealed in insulation crust and the silastic material with capacitor (6).