CN2128741Y - Energy-saving and anti-stealing electricity apparatus for electric meter - Google Patents

Abstract

The utility model provides an electric meter, in particular to an energy-saving and anti-stealing electricity apparatus for a single-phase electric meter. The utility model contains an electronic switch connected in series and a capacitance connected in parallel on the voltage coil of the electric meter, wherein, the electronic switch is composed of a current transformer, a rectifying and filtering circuit, a current limiting voltage stabilizing circuit and a switching circuit.

Description

Energy-saving and anti-stealing electricity apparatus for electric meter

The utility model relates to a kind of watt-hour meter, especially the energy saver of single-phase watt-hour meter.

The present watt-hour meter that uses, its potential winding is the pure inductance element, and its power factor is very low, and general COS φ is about 0.2～0.3, so reactive loss is very big.No matter whether it has load, at every moment all at consumed power, be that 1.5W calculates by the potential winding of general watt-hour meter, so 1 year consumed power of every ammeter is 13 kilowatt-hours, because every household all will use watt-hour meter, the annual electric energy with regard to this consumption in the whole nation has been exactly an astronomical figure.

The purpose of this utility model is that a kind of energy saver will be provided, and electric energy loss when it can prevent effectively that the potential winding of ammeter is unloaded and compensation have the reactive loss when carrying, thereby make ammeter energy-conservation; Another purpose provides a kind of anti-electricity-theft device.

The purpose of this utility model is achieved in that switch of installing makes watt-hour meter automatically shut down potential winding when zero load in watt-hour meter, automatic again turning-on voltage coil of when carrying is arranged, at this moment neither influence the current return of watt-hour meter, do not influence the metering and the precision of watt-hour meter again; Secondly at electric capacity of voltage table potential winding two ends parallel connection, the reactive loss during the bucking voltage coil working.

So the battery saving arrangement that the utility model only need be little at former single-phase watt-hour meter built-in one volume, include on-off circuit and building-out capacitor is simple in structure, cheap.The utility model also improves the process structure and the local form of watt-hour meter connection terminal disk, terminal 5 is located in the watchcase, wiring hole changes into to the both sides left and right directions, installs an one pole two wires residual current circuit breaker additional between the turnover line terminals, constitutes anti-electricity-theft device.

Concrete structure of the present utility model embodiment and accompanying drawing thereof hereinafter is illustrated.

Fig. 1 has showed a kind of novel watt-hour meter front elevation that has economize on electricity and anti-electricity-theft device;

Fig. 2 has showed the circuit diagram of energy saver;

Fig. 3 has showed former watt-hour meter wiring schematic diagram;

Fig. 4 has showed improvement back wiring schematic diagram;

Fig. 5 has showed a kind of novel complete electrical schematic diagram that has the watt-hour meter of energy-conservation and anti-electricity-theft device.

Switch of installing makes watt-hour meter automatically shut down potential winding when zero load in watt-hour meter, and automatic again turning-on voltage coil of when carrying is arranged, and at this moment neither influences the current return of watt-hour meter, does not influence the metering and the precision of watt-hour meter again; Secondly capacitor in parallel at the meter voltage coil two ends, the reactive loss during the bucking voltage coil working, the circuit diagram of whole energy saver as shown in Figure 2, electronic switching circuit, C are formed in wherein (1)-(4) ₂Be building-out capacitor.

Electronic switch is using silicon controlled switching characteristic, control the DC side break-make of bridge rectifier circuit, form AC contact-less switch, circuit shown in Fig. 2 (4), be not difficult to find out,, between the silicon controlled control utmost point and negative electrode, just provide constant trigger voltage as long as watt-hour meter has load, make controllable silicon SCR conducting at any time, potential winding Qu just has alternating current to pass through.When the ammeter load was 0, trigger voltage disappeared, and the controllable silicon pulse direct current of flowing through flows through at 0 o'clock, and controllable silicon SCR is turn-offed, and Qu is also blocked, and silicon controlled negative electrode serial connection light emitting diode DG monitors that whether working properly controllable silicon SCR is, and Fig. 1 is seen in the installation site.Silicon controlled control voltage is next from the current transformer LH conversion in current watt-hour meter loop, and as Fig. 2 (1), current transformer LH can seal in current return in the table separately, is preferably in the watt-hour meter to add around a secondary coil on the current coil.

When watt-hour meter has when carrying, controllable silicon SCR conducting continuously just can make watt-hour meter normally measure, and silicon controlled is controlled voltage and should be triggered at any time like this, must carry out Filtering Processing after the AC signal rectification that obtains from current transformer, as Fig. 2 (2).R ₂Be discharge resistance, when watt-hour meter is unloaded, capacitor C ₁Stored electric charge is through R ₂Bleed off, controllable silicon SCR is turn-offed as early as possible.

Because the current return of watt-hour meter changes, damage controllable silicon for fear of when loading greatly, causing the control overtension, string is gone up R behind rectifying and wave-filtering ₁Make current limliting, and insert stabilivolt DW and come the amplitude limit stable voltage control, shown in Fig. 2 (3).

This on-off circuit does not need other direct supply.The voltage breakdown of stabilivolt DW should be greater than the control voltage of controllable silicon SCR; R ₁Resistance should adjust to watt-hour meter minimum load value the time, can make till the controllable silicon SCR conducting, be generally about 1K Ω; R ₂Resistance, for discharge, should be the smaller the better, but the current source of importing previously can not be desirable constant current supply, so R ₂Little, when watt-hour meter does not guarantee control voltage during at little load, generally answer R ₂＞＞R ₁, and R ₂Should adjust according to trigger voltage and other related factors of controllable silicon SCR, generally at 80-100K Ω.Filter capacitor C ₁Capacity can not be excessive, not so can prolong discharge time, timely shutoff voltage coil when watt-hour meter is unloaded generally at 10-15 μ F, is a principle as long as can satisfy the continuous conducting of controllable silicon SCR.In a word, the parameter request of each element of electronic switch, it is so high not need to resemble accurate electronic device, and it only needs to satisfy at 2 and get final product, and the one, energy turning-on voltage coil can accurately measure when supposition watt-hour meter minimum load (as supposition 2.2W); The 2nd, shutoff voltage coil as early as possible when watt-hour meter is unloaded.

Building-out capacitor C ₂Selection, be example with the related parameter that has of DD28 type potential winding: P=1.5W COS φ=0.25, calculate Q=5.809Var in view of the above, make COS φ bring up at 0.9 o'clock from 0.25

Qc＝P（tgφ1－tgφ2）＝1.5（3.873－0.4843）＝5.083Var，

$\mathrm{Qc}=\frac{U^2}{X_c}=\frac{{\mathrm{<figure-callout\; id="2"\; label="U"\; filenames="912252146\_DRIMG1.png,912252146\_DRIMG2.png"\; state="\{\{state\}\}">U</figure-callout>}}^2}{\frac{1}{2\mathrm{\&pi;fc}}}=2\mathrm{\&pi;fc}\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="U"\; filenames="912252146\_DRIMG1.png,912252146\_DRIMG2.png"\; state="\{\{state\}\}">U</figure-callout>}}^2$

C＝ (Qc)/(2π fU ²) ＝ 5.083/(2×3.14×50×220 ²) ＝0.3343μF

Can choose the capacitor that nominal capacitance is 0.33 μ F400V, preferably produce 0.35 μ F450V capacitor specially.

Fig. 3 is seen in the wiring of old-fashioned watt-hour meter signal, from figure, utilizes the method for watt-hour meter stealing generally to have three kinds, and the irregular open terminal 5 of the first makes potential winding Qu dead electricity in the table and sends a telegraph the table stall; It two is resistance wire R in parallel between terminal 1 and 2, and it is a part of that the load of watt-hour meter is shunted from resistance R, influence the measuring accuracy of watt-hour meter, with the realization stealing; It three is live wire and center line reverse grafts with inlet wire, as (L) (N) connection, does a temporary ground wire (not meeting center line N), finds out that from figure lamp 3 does not just pass through meter current coil, and the load of lamp 3 has just formed stealing.

At the problems referred to above, novel watt-hour meter improves the process structure and the local form of pair of wire connection terminals dish, as shown in Figure 1.

1, with terminal 5 processing in watchcase, produce good ammeter, seal up watchcase is fastening behind to be corrected the finishing, do not allow the user tear open arbitrarily.

2, wiring hole by original changing into downwards to the both sides left and right directions, the wiring holding screw exposes, and must not open the terminal disc cover plate during wiring, the terminal disc cover plate does not allow to unload in the front, positive only being permitted the residual current circuit breaker switch exposing operation when being convenient to trip.So just be not easy the cross-over connection shunt resistance.

3, between the turnover line terminals, install an one pole two wires residual current circuit breaker JDLK-DA1/2 fuse additional.This isolating switch has electric leakage, overload, short circuit, the protection of LN misconnection, makes L, the N can not the reverse graft stealing like this, can protect watt-hour meter and household electrical appliance again, has guaranteed personal safety.Connection after the improvement wiring is seen Fig. 4.Complete electrical schematic diagram such as Fig. 5 of the watt-hour meter of novel energy-conservation and anti-electricity-theft device.

The utility model has the advantages that on former kilowatt-hour meter basis and improve that cost simple in structure is low, energy-saving effect is remarkable.

Claims (5)

1, a kind of energy saver of single-phase watt-hour meter is characterized in that this device includes on the meter voltage coil electronic switch of serial connection and and connects a capacitor.

2, the described energy saver of claim 1 is characterized in that described electronic switch is made up of current transformer (1), current rectifying and wave filtering circuit (2), current limliting mu balanced circuit (3), on-off circuit (4), four parts.

3, the described energy saver of claim 2 is characterized in that described current transformer is to add around a secondary coil to constitute in meter current coil; Rectifier filer is a bridge full-wave rectifier, dielectric capacitance filtering; The current limliting mu balanced circuit is by resistor R ₁Current limliting, stabilivolt DW does the amplitude limit voltage stabilizing; Electronic switching circuit is with four rectification diode D ₁-D ₄Be connected into bridge circuit, the anode and the negative electrode of DC side diametrical connection controllable silicon SCR connect the 220V AC power behind the AC side diagonal angle serial connection meter voltage coil.

4, the described energy saver of claim 3 is characterized in that light emitting diode DG of serial connection on described controllable silicon SCR, so that monitor voltage coil operating mode.

5, a kind of anti-electricity-theft device of single-phase watt-hour meter is characterized in that the terminal 5 of potential winding on the watt-hour meter is changed in the watchcase; Turnover line wiring hole towards the left and right sides, the left side is outlet for the inlet wire right side; Terminal strip can not unload in the ammeter front; The wiring holding screw exposes; Install a residual current circuit breaker fuse additional between the watt-hour meter turnover line; The terminal disc cover plate leaves residual current circuit breaker switch handle hole.

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