CN2935580Y

CN2935580Y - Compound overvoltage protection device

Info

Publication number: CN2935580Y
Application number: CN 200620079394
Authority: CN
Inventors: 李力军
Original assignee: Legrand Low Voltage Wuxi Co Ltd
Current assignee: Legrand Low Voltage Wuxi Co Ltd
Priority date: 2006-07-18
Filing date: 2006-07-18
Publication date: 2007-08-15
Anticipated expiration: 2016-07-18

Abstract

The utility model discloses a compound over voltage protector which consists of a resistance-capacitance circuit and a lightning proof circuit. The two circuits share the same zinc oxide nonlinear resistance. The resistance-capacitance circuit consists of a resistance and a dry capacitance. The lightning proof circuit consists of a resistance and a resistive discharge gap, A, B and C being the phase poles, N being the ground pole, one end of the A, B, C and N poles connected together and form a neutral point O and the other end connected with the A phase line, B phase line, C phase line and ground line N of the protected equipment, all poles of the protector are parallelly connected by capacitance components and the discharge gap and serially connected with the capacitance components. The utility model has the advantages of simple structure, convenient use and energy saving, and protective functions to the operation over voltage and atmospheric over voltage; the zinc oxide nonlinear resistance technology is adopted, which extends the service life and greatly reduces the harm from high-order harmonics in power grid, no additional capacitive current provided. The resistance-capacitance circuit has a four-pole structure without gap and the lightning proof circuit has a four-pole structure with gap, which provide not only phase-to-phase but also phase-to-ground protection.

Description

A kind of combined type overvoltage protection device

Technology neck city

The utility model relates to medium voltage network overvoltage protection field, a kind of combined type overvoltage protection device of the double protection functions of particularly suitable switching overvoltage and atmospheric over-voltage.

Background technology

One, existing overvoltage protection device is divided into rc absorber and traditional zinc oxide arrester, is divided into composite type and acyclic type again on structure.The defective that this structure exists has:

1., to superpotential protection, knockdownly not only can protect alternate but also can protect relatively, the only protection of acyclic type relatively, function singleness.

2., rc absorber is to the switching overvoltage Finite Amplitude and reduce the effect of frequency, but is not available to protect atmospheric over-voltage; Lightning arrester is to switching overvoltage and all effects of Finite Amplitude of atmospheric over-voltage, but it cannot reduce the frequency of switching overvoltage.

3., can produce the higher-order of oscillation overvoltage during vacuum circuit-breaker operation inductive load, the high-potential gracient that this high frequency overvoltage is produced will puncture the turn-to-turn insulation of inductive load.

4. therefore present surge absorber or only protect switching overvoltage; Perhaps only protect atmospheric over-voltage, to switching overvoltage protection imperfection.

Two, the defective of existing combined type overvoltage protection device existence such as (or being capacitance-resistance combined arrester, capacitance-resistance valve overvoltage protection device) has:

1., linear resistance and capacitances in series are adopted in the capacitance-resistance loop.Provide the additional capacitor electric current to electrical network, not energy-conservation, long-term heating.And be subject to the harm of electrical network high order harmonic component.

2. or the capacitance-resistance loop adopt nonlinear resistance and capacitances in series.Parameter designing is unreasonable, nonlinear resistance chargeability height, and insulation coordination is bad.

3., zero-clearance zinc oxide valve block, residual voltage height are adopted in lightning-arrest loop; Or adopt zinc oxide valve plate and gap series connection, but design the unreasonable function of having lost the alternate protection in lightning-arrest loop.

Summary of the invention

The purpose of this utility model provides a kind of structure tube list, and is easy to use, energy savings, and prolong useful life, is not subjected to the influence of electrical network high order harmonic component, and a kind of combined type overvoltage protection device of additional capacitor electric current is not provided.

In order to overcome the deficiencies in the prior art; the technical solution of the utility model is to solve like this: the combined type overvoltage protection device; form by two loops in capacitance-resistance loop and lightning-arrest loop; article two, the shared znr in loop; the capacitance-resistance loop is made up of resistance and dry type electric capacity; lightning-arrest loop is made up of resistance and resistive discharging gap; A; B; C is the phase utmost point; N is the earth polar; A; B; C; N four utmost points have an end to link together to be neutral point 0; the other end then is connected to the A phase line of protected equipment; the B phase line; on C phase line and the ground wire N; its improvements of the present utility model are: every utmost point of protector is connected in parallel by capacity cell and discharging gap, again with the resistive element composition that is connected in series.

The utility model compared with prior art; structure tube list; easy to use; energy savings; realized the function that switching overvoltage and atmospheric over-voltage are protected simultaneously; owing to adopted the znr technology, prolong useful life, and the harm that has greatly reduced the electrical network high order harmonic component does not provide the additional capacitor electric current.Gapless four pole type structure is adopted in the capacitance-resistance loop, and the four pole type structure of four clearance types is adopted in lightning-arrest loop.Not only can protect alternate but also can protect relatively.

Description of drawings

Fig. 1 is the utility model electrical wiring theory structure schematic diagram;

Fig. 2 is the single-phase connection principle structural representation of Fig. 1;

Fig. 3 is the enforcement mode of connection structural representation of Fig. 1;

Fig. 4 is the contour structures schematic diagram of Fig. 1.

Embodiment

Accompanying drawing is a specific embodiment of the utility model

Below in conjunction with accompanying drawing particular content of the present utility model is described further:

Shown in seeing figures.1.and.2; form by capacitance-resistance loop I and two loops of lightning-arrest loop II; article two, the shared znr R in loop; capacitance-resistance loop I is made up of resistance R and dry type capacitor C; lightning-arrest loop II is made up of resistance R and resistive discharging gap G; A; B; C is the phase utmost point; N is the earth polar; A; B; C; N four utmost points have an end to link together to be neutral point 0; the other end then is connected to the A phase line of protected equipment; the B phase line; on C phase line and the ground wire N; every utmost point of its protector is connected in parallel by capacity cell C and discharging gap G, again with the resistive element R composition that is connected in series.Be used for changing the operating state of circuit, reduce the frequency and the steepness of switching overvoltage, simultaneously the amplitude of over-voltage.The overvoltage protection of medium voltage network mainly is meant the protection to atmospheric over-voltage and switching overvoltage.

When system normally moved, ZnO resistors was high-impedance state (resistance mega-ohms) and isolates with electrical network; When switching overvoltage appears in system, ZnO resistors conducting under the overvoltage effect (resistance ohm level), because the logical friendship of capacitor hinders straight characteristic, overvoltage will be by the capacitance-resistance loop; When atmospheric over-voltage appears in system, the resistance conducting, not conducting of electric capacity, discharging gap punctures, and overvoltage will be by lightning-arrest loop.

With reference to Fig. 3 mode of connection, protector is installed in the vacuum switch lower end, and is in parallel with protected equipment, A, B, C three-phase respectively with switch cubicle in busbar A, B, C three-phase link to each other earth polar N phase reliable ground.

With reference to Fig. 4, shown in Figure 5, product is that in-line is arranged no exposed metal/bare metal terminal.

In sum, A, B, C, N four set of pieces are formed four stars shape one word row structure.Element A, B, C form the alternate overvoltage protection device of AB, AC, BC in twos; They form the overvoltage protection device relatively of AN, BN, CN simultaneously again respectively with element N.Alternate superpotential multiple can be restricted to and the identical or slightly high level of overvoltage multiple relatively; When the network system operate as normal, isolate with it, can not increase capacity current, can also reduce of the harm of the harmonic wave of electric network pollution resistance, capacity cell in this device to electrical network; It is big to have through-current capability, ageing-resistant and good, the more rational characteristics of insulation coordination of explosion-proof performance; Reduce the frequency and the wave head steepness of switching overvoltage with the capacitance-resistance loop, over-voltage gets amplitude simultaneously; With lightning-arrest loop restriction atmospheric over-voltage and the higher switching overvoltage of amplitude.Therefore, the combined type overvoltage protection device is that protection is the most perfect at present, the best combined type overvoltage protection device of protection effect.

Claims

1; a kind of combined type overvoltage protection device; form by capacitance-resistance loop (I) and lightning-arrest loop (II) two loops; article two, the shared znr in loop (R); capacitance-resistance loop (I) is made up of resistance (R) and dry type electric capacity (C); lightning-arrest loop (II) is made up of resistance (R) and resistive discharging gap (G); A; B; C is the phase utmost point; N is the earth polar; A; B; C; N four utmost points have an end to link together to be neutral point O; the other end then is connected to the A phase line of protected equipment; the B phase line; on C phase line and the ground wire N; it is characterized in that: every utmost point of protector is connected in parallel by dry type electric capacity (C) and discharging gap (G), again with resistance (R) composition that is connected in series.

2, a kind of combined type overvoltage protection device according to claim 1 is characterized in that described A, B, C, N four set of pieces composition four stars shape word order structure.

3, a kind of combined type overvoltage protection device according to claim 1; it is characterized in that described A, B, C form the alternate overvoltage protection device of AB, AC, BC mutually very in twos, they form the overvoltage protection device relatively of AN, BN, CN simultaneously again respectively with element N.

4, a kind of combined type overvoltage protection device according to claim 1 is characterized in that housing does not have the exposed metal/bare metal terminal.