The household electrical appliances lightning protection busbar
Technical field
The utility model relates to weak electricity system lightning protection and overvoltage protection field, is specifically related to a kind ofly prevent to be struck by lightning and the design of the superpotential household electrical appliances insert row of lightning surge.
Background technology
Thunder and lightning is a kind of natural phenomena that has destructive power, and a large amount of damage to crops caused by thunder accidents all can take place every year in China.Particularly annual all have large quantities of electric equipments or household electrical appliance because of thunderbolt damages, and caused direct economic loss.The shocking preventing technology of power plant substation primary equipment is gradually improved in recent years, but also has many leaks in weak electricity system lightning protection field, and many damage to crops caused by thunder accidents have also taken place.The lightning protection of weak electricity system and overvoltage protection are a kind of system engineerings, must integrated use shunt (earial drainage), all press (equipotential), shielding, ground connection and protection every technology such as (clamps), constitute a complete protection system, just can get capable obvious effects.
Shunting (earial drainage): be for the direct lightning strike that may occur.By the downlead and the earthing device of arrester, or, lightning current is scattered into ground, and do not flow through protected equipment and parts by conduction connection and ground connection good metal framework.
All press (waiting voltage): be that different cable sheaths, device housings, metal frame, the pipeline at the same position of same floor are done electric overlap joint, with balanced current potential.
Shielding: be to adopt shielded type cable, utilize artificial shielded box, the natural shield overvoltage energy that stops, decays.
Ground connection: be that all metal frames, pipeline, cable shield etc. are connected with general earthed system.
(clamp) protection: be at power line, holding wire, connect all of the port that overvoltage such as protective earthing line PE may be invaded, the overvoltage surge protective device that installing is necessary; Install multi-stage protection on the network holding wire; The impulse overvoltage of invading is clamped down on level in withstand voltage permission.
For the person, home appliance in the building are not struck by lightning, must do lightning protection.No matter thunder and lightning is crossed electric wave is invaded from any approach, all must be in the shortest time (nanosecond),, protected circuit and equipment are inserted in the equipotential system on the spot, make each port equipotential of circuit and equipment nearby.Discharge simultaneously on the circuit because of thunderbolt produces a large amount of pulse energies,, reduce the potential difference of each port of equipment to greatest extent, thereby reach the purpose of protection circuit and equipment with the shortest path the earth of releasing.By every lightning protection measures, for home appliance provides a good environment, following several aspect is specifically arranged: on the one hand, energy lightning current huge, out of control is released into ground protection automated system communication and controller switching equipment by the surge protector that is installed on low-voltage distributing line and the signal line in the time of nanosecond; On the other hand, " break " " lead to " that absorbs inductive load on the circuit and the capacitive load surge voltage that causes reaches protection to the possible mistake input voltage of phase voltage.
For the damage that prevents from electronic equipment to be caused because of reasons such as LEMP, switching electromagnetic pulse and static discharges.International and domestic standardization body has issued a series of standards and norms.IEC61312 and GB50057-94 (2000) propose and have stipulated the notion and the method for systematic protection respectively.Inside and outside building, set up the equalized voltage system, and in the application of reality, obtained good effect.The lightning protection of Modern Significance; its focus is from the object of protection of attaching most importance to building; develop into the electronic information is the protection of core; emphasize the comprehensive regulation, whole defence, classification earial drainage, the thinking of setting up defenses in depth; lightning protection is regarded as a system engineering, and the secondary device lightning protection measures as shown in Figure 3.
In sum, be not struck by lightning, must be done lightning protection in order to make the person, home appliance in the building.Lightning Protection Design is exactly to be equalized voltage system of protected device build, and the utility model patent has designed the household electrical appliances lightning protection busbar, by the lightning protection unit lightning current bleed off being gone into ground, reaches the purpose of real protection home appliance.
The utility model content
The utility model is at the shortcoming of above-mentioned prior art, and a kind of simple in structure, household electrical appliances lightning protection busbar that lightning protection properties is good is provided.
The technical solution adopted in the utility model is: a kind of household electrical appliances lightning protection busbar, described household electrical appliances lightning protection busbar comprises lightning protection unit and output unit, described lightning protection unit is installed in the insert row, and near the electric power incoming line side, described electric power incoming line is made up of live wire, zero line and protective earthing line, the inductance that described lightning protection unit is connected in series by the gas discharge tube that links with live wire and protective earthing line parallel, with live wire, forms with the electric capacity that the protective earthing line parallel is connected with live wire; Described output unit is made of many groups jack.
As further improvement of the utility model:
Described gas discharge tube adopts ceramic enclosed package, and inner metal electrode by two band gaps fills with argon gas or neon formation;
Described metal electrode, when the voltage that is added to two electrodes reached the gas breakdown that makes in the gas discharge tube, gas discharge tube just began discharge, and became low-resistance by high resistant, made the voltage of electrode tip be no more than puncture voltage;
Described inductance and live wire are connected in series, and the induction reactance value of described inductance is 0.1 μ H;
Described electric capacity is connected with the protective earthing line parallel with live wire, and the capacitor value of described electric capacity is 0.1 μ f.
The utlity model has following advantage: the utility model can limit lightning wave effectively and be delivered to appliance system by electric power incoming line by the lightning protection unit is installed at the electric power incoming line place; Inductance of connecting with live wire and the electric capacity that is connected in parallel between live wire, the protective earthing line PE can effectively carry out low-pass filtering, and the high fdrequency component that contains in the filtering lightning wave signal greatly reduces the harm of higher-energy to power-supply system; Gas discharge tube is parallel between live wire and the protective earthing line PE; its discharge capability is strong; provide the bleed off path to surge voltage; protection equipment or system avoid the damage of lightning overvoltage; improve the performance of the anti-lightning strike and overvoltage surge of power-supply system, thereby improved the stability and the functional reliability of household electrical appliances insert row output voltage.The utility model, simple, lightning protection properties good, can significantly improve the lightning protection properties of household electrical appliances insert row.
Description of drawings
Fig. 1 is the structural representation of the utility model embodiment household electrical appliances lightning protection busbar;
Fig. 2 is the approach sketch of lightning surge invasion low-pressure system;
Fig. 3 is the secondary device lightning protection measures schematic diagram of prior art.
Embodiment
As described in Figure 1, the household electrical appliances lightning protection busbar of the utility model embodiment comprises lightning protection unit 1 and output unit 2, the lightning protection unit is installed in the inner close electric power incoming line side of insert row in the present embodiment, electric power incoming line is made up of live wire L, zero line N and protective earthing line PE, and lightning protection unit 1 is formed by the inductance 4 that is connected in series with the gas discharge tube 3 of live wire L and protective earthing line PE binding in parallel, with live wire L with the electric capacity 5 that live wire L and protective earthing line PE are connected in parallel in the present embodiment; The induction reactance value of inductance 4 is 0.1 μ H; The capacitor value of electric capacity 5 is 0.1 μ f; The output unit 2 of the household electrical appliances lightning protection busbar in the present embodiment is made of many groups jack.
As shown in Figure 2, the approach of weak electricity systems such as thunder and lightning intrusion household electrical appliances has: the one,, by the electromagnetic induction transmission, be that thunder and lightning is near low-voltage circuit when movable, the field that thunder and lightning forms will produce very high induction overvoltage on the line, and reach low voltage electric power system or the household electrical appliance that are connected on the low voltage electric network along circuit, because this interference voltage is far longer than the working power voltage of weak current equipment such as household electrical appliances, thereby cause the damage of electric equipment.The 2nd,, by the capacitive coupling transmission, promptly thunder and lightning is attacked directly in building, and lightning current is introduced earth mat through lightning rod, will produce very high potential difference on the node at earth mat when lightning current looses stream by earth mat.Because earth mat and secondary cable shielding layer are directly or link to each other indirectly, this potential difference can be applied to make on the shielding skin of cable and by the capacitive coupling effect and produce voltage and current on the cable core, if this interference voltage amplitude surpasses the interference maximum that the electric equipment supply voltage can bear, low voltage equipment is damaged.Thereby need the lightning protection unit be installed in the insert row position, prevent thunderbolt.
Gas discharge tube 3 among the utility model embodiment is installed in the electric power incoming line side of insert row, and electric power incoming line is made up of live wire L, zero line N and protective earthing line PE, and gas discharge tube 3 is installed in parallel between live wire L and protective earthing line PE.Gas discharge tube 3 is that a pair of discharging gap is encapsulated in the glass or pottery that fills with discharge medium (as inert gas), promptly constitutes gas discharge tube.Discharge tube impact flashover voltage commonly used lies prostrate several kilovolts more than 100, in case when impulse overvoltage reaches the discharge tube impact flashover voltage, the interior gas ionization of pipe, discharge tube becomes approximate short circuit by original open-circuit condition.
Gas discharge tube 3 discharge capabilities are strong, discharge capacity big (can accomplish more than the 100kA), and the insulation resistance height, the characteristics that leakage current is little, gas discharge tube also claims lightning-arrest pipe.Gas discharge tube 3 has very strong surge absorbability, very high insulation resistance and very little parasitic capacitance, can not bring any adverse effect to the equipment of operate as normal.Gas discharge tube 3 is in circuit and protected equipment parallel connection.When not having surge voltage, the impedance of gas discharge tube 3 is very big, can conducting.When surge voltage was invaded, the gas molecule generation ionization that gas discharge tube is 3 li produced free electron and cation, and at this moment gas just becomes and can conduct electricity.At this moment, tube voltage drop descends, and the equipment both end voltage is reduced, and provides the bleed off path to surge voltage like this, and protection equipment or system avoid the damage of lightning overvoltage.Therefore, installing 3 pairs of lightning surge energy of gas discharge tube additional absorbs.
Inductance 4 among the utility model embodiment is connected in series with live wire L, and inductance 4 is between gas discharge tube 3 and electric capacity 5, and inductance value is elected 0.1 μ H as; Electric capacity 5 among the utility model embodiment is installed in parallel between live wire L and protective earthing line PE, is positioned at the right side of inductance 4, and capacitance is 0.1 μ f.
The frequency that thunder and lightning disturbs mainly is distributed in about 1MHz, roughly is distributed in 100KHz~10MHz frequency range.In order to guarantee the electronic equipment operate as normal, must be with the effective filtering of high fdrequency component in this scope.So basis
Choose reasonable inductance L and capacitor C parameter.L, C parameter should be selected by " Technological Economy ratio " principle, not only will satisfy specification requirement, and be economical and practical again.Because the volume of inductance is bigger, it is cumbersome to make inductance coil, is unfavorable for large-scale production and is not easy to integrated and miniaturization, so cost is higher, generally for reduced volume, reduces cost, can use less inductance.Because lightning wave has characteristics such as peak value height, energy are big, therefore can adopt inductance 4, electric capacity 5 to carry out low-pass filtering, filter the high fdrequency component in the lightning wave.
Because lightning wave has characteristics such as peak value height, energy are big; in order to reduce the overvoltage that enters weak electricity system as far as possible; lightning protection unit 1 should be installed at the insert row place; part high fdrequency component that contains in the lightning wave signal and higher-energy constitute harm to power-supply system, therefore can adopt the LC low pass filter to carry out filtering and install 3 pairs of thunder and lightning energy of gas discharge tube additional to absorb.By multistage lightning protection measures, the thunder and lightning energy is released step by step, thereby can will invade the overvoltage Limiting of home appliance a reasonable levels.
The above only is a preferred implementation of the present utility model, and protection range of the present utility model also not only is confined to the foregoing description, and all technical schemes that belongs under the utility model thinking all belong to protection range of the present utility model.Should be pointed out that for those skilled in the art, also should be considered as protection range of the present utility model in the some improvements and modifications that do not break away under the utility model principle prerequisite.