CN2638313Y

CN2638313Y - Reactive compensation and arc-extinguishing resonance-extinguishing device

Info

Publication number: CN2638313Y
Application number: CN 03277338
Authority: CN
Inventors: 徐东; 方文; 夏咸福
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-07-31
Filing date: 2003-07-31
Publication date: 2004-09-01
Anticipated expiration: 2013-07-31

Abstract

The utility model relates to a reactive power compensation and arc-suppression and harmonic elimination device that is suitable for a non-effectively earthed system neutral point at or below 35 KV. The utility model is characterized in that a capacitance is respectively connected with the ground terminals of three three-phase rapid fuse in series, a current transformator is also arranged, and the induced current output ends of the current transformator are respectively connected with a microcomputer composite controller. The utility model can provide certain reactive power compensation, restrict the atmospheric over-voltage and operate the over-voltage and resonance over-voltage, and can also effectively protect the single phase arc earthing overvoltage, choose the line selection device with high selectivity and replace the present arc suppression coil and other arc-suppression and harmonic elimination device.

Description

Reactive power compensation and extinguishing arc harmonic elimination apparatus

Technical field

The utility model relates to the extinguishing arc harmonic elimination apparatus that is applicable to 35KV and following system with non effectively earth ed neutral.

Background technology

Along with the continuous development of national economy, electric power system constantly increases, and it is more and more important that its safe operation and power supply reliability also seem.Because the power consumption equipment of large industrial enterprise constantly increases, and the power distribution network of the long-term 6-66KV of China adopts the operational mode of isolated neutral mostly, the electric current of fault point of flowing through behind the single-phase earthing is bigger, electric arc is difficult for extinguishing, be easy to generate intermittence arc grounding overvoltage, cause the emergency stop valve trip rate obviously to rise.

In order to address the above problem, many electrical networks have adopted the resonance grounding mode, promptly at neutral point installing arc suppression coil, when single-phase earthing takes place when, the inductance current that is produced by arc suppression coil is to the compensation of fault point capacity current, the residual flow of the fault point of flowing through is reduced, reach nature and extinguish, the accident that prevents further enlarges even eliminates the purpose of fault.Practical operating experiences shows, the system of neutral by arc extinction coil grounding, and the apparatus insulated damage that causes by single-phase arc grounding, even explosion accident still happens occasionally.The compute that capacitance current is changed because of arc suppression coil and measure very reason such as complexity, be difficult to operate in best gear,, often make the residual flow in compensation backarc road bigger especially for fear of resonance compensation, being still within the bounds of possibility of resume combustion after the zero passage finally causes the extinguishing arc failure.Arc suppression coil compensation only be the power frequency capacitance current, and actual electric current by earth point not only has the power frequency capacitance current, but also comprise a large amount of high-frequency currents and current in resistance property, the sustained combustion that only high-frequency current and current in resistance property just can pilot arcs when serious, this is that arc suppression coil is insurmountable at all.The arc suppression coil volume is big in addition, and assembly is many, the cost height.Along with the expansion of electrical network, arc suppression coil with to change, be unfavorable for long-term planning.

Summary of the invention

At problems of the prior art, by improving, the utility model provides a kind of reactive power compensation and extinguishing arc harmonic elimination apparatus that can substitute arc suppression coil and other extinguishing arc harmonic elimination class devices.

Realize that the above-mentioned purpose technical solution is such:

Reactive power compensation and extinguishing arc harmonic elimination apparatus; comprise combination overvoltage protector, an isolating switch, three fast acting fuses, three phase-splitting vacuum switches, a discharge coil and a microcomputer general controller; it is characterized in that: respectively at the earth terminal of three fast acting fuses of the three-phase electric capacity of connecting; earth terminal at three electric capacity of three-phase; be provided with a current transformer, the induced current output of described three current transformers is connected respectively on three current-to-voltage converters of microcomputer general controller.

The utility model is by the variation to the electric current that flows through each phase electric capacity, and the system exception phenomenon is differentiated, and because of the current waveform that flows through electric capacity changes greatly, the electric current that flows through electric capacity is directly proportional with the voltage at the frequency that flows through electric capacity, electric capacity two ends.Maximum 2.5pu appears about overvoltage 2pu on metallic earthing takes place, perfecting mutually.Maximum 3.5pu appears about overvoltage 3pu on the intermittence arc grounding takes place, perfecting mutually.And fault is compared sound going up mutually about the low 1.5pu of the overvoltage that occurs, so differentiate accurately.Device instantaneous operation, fault reduce the fault phase-to-ground voltage rapidly on the one hand mutually by coil ground connection, and electric capacity and discharge coil are formed the resonance damping on the other hand, discharge one time the high-frequency resonant energy, help system safety.Match electric capacity in addition according to actual needs and can compensate certain inactivity, improve power factor.

The utility model can provide certain reactive power compensation, also can limit atmospheric over-voltage, switching overvoltage, resonance overvoltage.Single-phase arc grounding overvoltage can be protected effectively, and the line selection apparatus of high selectivity can be matched.This device volume is little, and price is low, and the reliability height is easy for installation, and the is applied widely remarkable advantage of Denging can substitute arc suppression coil and other extinguishing arc harmonic elimination class devices.

Description of drawings

Fig. 1 is the utility model circuit theory diagrams.

Embodiment

This reactive power compensation and extinguishing arc harmonic elimination apparatus comprise combination overvoltage protector 3, isolating switch 7, three fast acting fuses 6, three phase-splitting vacuum switches 1, discharge coil 5 and microcomputer general controller 4.At the earth terminal of three fast acting fuses 6 of the ABC three-phase electric capacity 2 of connecting respectively, earth terminal at three electric capacity 2 of ABC three-phase, be respectively equipped with a current transformer 8, and the induced current output of three current transformers 8 is connected respectively on three current-to-voltage converters of microcomputer general controller 4 and sees Fig. 1.

When system normally moved, three phase-splitting vacuum switches 1 all were in the state of cut-offfing, and any influence can not take place when system normally moves, and when system's generation single-phase earthing, vacuum switch 1 is finished the operation of discharge coil according to instantaneous deciliter of the instruction of general controller.

For example: when the intermittence arc grounding took place A mutually, the electric capacity of A phase certainly led to the impulse electricity of concussion, electric capacity two ends overvoltage, and B, C maximum 3.5pu occurs about overvoltage 3pu on mutually.And A compares about the low 1.5pu of overvoltage that B, C go up to occur mutually, and signal amplitude is obvious, and current transformer 8 produces current changing signals and passes to microcomputer integrated treatment device 4, and signal is through 4 integrated treatments of microcomputer integrated treatment device and analyze, and assigns command signal.Make the phase-splitting vacuum switch 1 that is connected in the A phase closed in short-term, because the phase ground voltage of A phase reduces rapidly, recovery voltage rises on the restriction arc road.The generation of the induction reactance electric current of discharge coil also stops arc light to be restriked simultaneously, impels earth point electric arc to extinguish fast.

Claims

1, reactive power compensation and extinguishing arc harmonic elimination apparatus; comprise combination overvoltage protector, an isolating switch, three fast acting fuses, three phase-splitting vacuum switches, a discharge coil and a microcomputer general controller; it is characterized in that: respectively at the earth terminal of three fast acting fuses of the three-phase electric capacity of connecting; earth terminal at three electric capacity of three-phase; be provided with a current transformer, the induced current output of described three current transformers is connected respectively on three current-to-voltage converters of microcomputer general controller.