CN2046220U

CN2046220U - Self-check three-phase voltage regulating device

Info

Publication number: CN2046220U
Application number: CN 88214519
Authority: CN
Inventors: 尚崇刚
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-09-29
Filing date: 1988-09-29
Publication date: 1989-10-18

Abstract

The utility model relates to a device which is suitable for compensating the errors of three phase voltage transformers with various voltage levels in supply mains and compensating errors generated by pressure drop on the secondary long cable lines of the three phase voltage transformers. The device uses two single stage voltage mutual inductors to divide the line voltage at a load end into voltages with various phasors in an automatic voltage division way, and then the voltages with various phasors are connected in series as a compensating voltage. The compensation is divided into an in phase adjusting disc and an orthogonal adjusting disc. The device realizes a self calibration function through two double stage voltage mutual inductors. The device is easy in field installation and use. The device can improve the precision of a watthour meter, and the index can reach 0.1 stage. The running of an electric network can not be affected when the device is installed.

Description

Self-check three-phase voltage regulating device

The utility model belongs to a kind of self calibration three-phase voltage adjusting gear that improves the accuracy of measuring.

The patent No. that prior art has Patent Office of the People's Republic of China to authorize is 87207696 " adjustable voltage compensator ".Its schematic circuit as shown in Figure 1.It is compensating ratio from amphitene circle N ', and C is parallel to secondary with capacity cell, and the pressure drop of the last generation of Ra, Rb in the line compensates angular difference, and compensation rate will change with the influence of line parameter circuit value Ra, Rb, and is very unstable.The patent No. that Patent Office of the People's Republic of China is authorized is 8520559 " threephase potential transformer voltage-drop compensation device ", adopted three-phase voltage on difference is separate, to compensate the method for angular difference each other, but because circuit is too simple, make ratio, the angular difference compensation rate mixes, be difficult for differentiating, use to bother very much when adjusting and be difficult to judge, in addition, more than two kinds of products the common fatal shortcoming of difference is arranged, be exactly only to notice how to compensate secondary voltage drop, how the scene of but not paying attention to carries out verification is detected, and makes on-the-spotly to use verification very complexity and equipment needed thereby are more, so that can not wide popularization and application.

The purpose of this utility model is that a kind of cost of design is low, and volume is little, and is durable in use, and compensation rate accurately and reliably, and is on-the-spot easy to adjust feasible, and the electric system that is applicable to that can calibrate voluntarily improves the self calibration three-phase voltage adjusting gear of electric energy metrical accuracy.

Schematic circuit of the present utility model is as shown in Figure 2: be wound with winding N a kind of comprising on the iron core 1 _AB, N ' _AB, N ' ab, be wound with winding N on the iron core 3 _BC, N ' _BC, Nbc self calibration three-phase voltage adjusting gear, it is characterized in that on iron core 1, increasing around winding Nab, on iron core 3, increase around winding Nbc, going up mutually with BC mutually at AB simultaneously increases the twin-stage standard mutual inductor respectively and forms.Wherein winding Nab and Nbc series connection, winding Nbc and Nab series connection constitute quadrature adjustment dish.The twin-stage standard mutual inductor that AB goes up mutually is by adding around winding N on

iron core

1 and 2 ₁₀And N ₂₀Form, the twin-stage standard mutual inductor that BC goes up mutually is by adding around winding N on iron core 3 and 4 ₃₀And N ₄₀Form, thereby constitute standard self-correcting loop.Working condition to AB phase part is described below: remove the input coil N that is wound with the AB phase on iron core 1 _ABWith the compensation ratio from amphitene circle N ' _ABOutside (forming ratio adjustment dish), on BC phase iron core 3, be wound with the coil N ' bc of compensation angular difference again, but, make and adjust comparatively difficulty because coil N ' bc not only plays the phase angle difference compensation mutually to AB, and contrast differences also plays compensating action simultaneously.In order to obtain pure angular difference compensation rate, on iron core 1, increase again around ratio tickler Nab simultaneously, be in series offsetting its contrast differences ancillary relief with coil N ' bc, thereby obtain pure angular difference compensation rate and form angular difference adjustment dish.So just make that the adjustment of compensation rate is greatly convenient, and ratio, angular difference can positive and negatively be regulated all.In like manner CB also is like this mutually.

Moreover, increased self-calibration function again for this device that makes things convenient for that solves field-checking.Like this, this device decapacitation is outside pressure drop compensates to the voltage transformer secondary lead, can also calibrate this device order of accuarcy that the back reached that is incorporated into the power networks voluntarily.This has just saved a lot of calibration equipments, makes on-the-spot very easy to use.It is finished by increasing the standard loop link.As shown in Figure 2, on iron core 1, be wound with input coil N _ABAnd compensating coil N ' _ABAnd on the basis of N ' ab, increase an iron core 2 again, on

iron core

1 and 2, be wound with ratio coil N simultaneously ₁₀And N ₂₀, and make coil N _AB, N ₁₀, N ₂₀The number of turn all equates.So just form the twin-stage voltage transformer (VT) standard loop of a 1:1, its accuracy rating can reach 0.05 grade at least.Because the second level exciting curent of twin-stage mutual inductor is very little, thus littler by this device second level input terminal Ao, Bo to the connection lead pressure drop between voltage transformer secondary lead-out terminal A ', the B ', can ignore.Because of the twin-stage transformer error is very little, also can ignore again.So just make _AOBO=

Ka if adjust the homophase dish and the quadrature dish of this device this moment, makes milivoltmeter mv reading be approximately zero, i.e. △

Ka=0, the then output end voltage of this device

Ab just equals the secondary output end voltage of voltage transformer (VT)

_AOBO, promptly

Ab=

Ka=

_AOBOLike this, the compensation rate of this device just falls to the pressure drop on voltage transformer secondary lead Ra, the Rb compensation fully, and the reading on this device reading dial is exactly a voltage transformer secondary lead voltage drop value at this moment.Also just realized calibration voluntarily.In like manner, CB also is like this mutually.

The utility model has the advantages that cost is low, volume is little, offset is stable, durable in use, field adjustable is convenient, and can calibrate voluntarily and improve the electric energy metrical accuracy.It is the comparatively desirable compensation equipment that the electric energy metrical accuracy improves in generating plant, transformer station.The overall accuracy of this device can reach 0.1 grade, and it not only can the pressure drop of bucking voltage mutual inductor secondary lead, can also improve the accuracy rating of voltage transformer (VT).

Embodiment of the present utility model:

Schematic circuit as shown in Figure 2.A ', B ', C ' are the voltage transformer secondary lead-out terminal; Ra, Rb, Rc are the impedance of voltage transformer secondary lead; A, B, C are an input terminal in this device; A, b, c are secondary output terminals; Ao, Bo, Co are the standard input terminal; Ao, bo, co are the standard lead-out terminal;

Ka, Kc is the standard output line voltage; Ab,

Cb is the secondary output line voltage; _AOBO, _COBOBe the voltage transformer secondary output line voltage; △

Ka, △

Kc is compensation back residue differential pressure; Ka, Da, Kc, Dc are the error of measurement lead-out terminal; Mv is a milivoltmeter, can be contained in this device, also can not be contained in this device, selects for use when to be used again.

Iron core

1,2,3,4 selects for use the thick silicon roll coil of strip system of 0.35mm to form, and the number of turn of each winding is as follows:

N _AB=2000 circles, N ' _AB=100 circles,

The Nab=100 circle, N ' ab=200 circle,

N _BC=2000 circles, N ' _BC=100 circles,

The Nbc=100 circle, N ' bc=200 circle,

N ₁₀=2000 circles, N ₂₀=2000 circles,

N ₃₀=2000 circles, N ₄₀The 40=2000 circle.

Claims

1, a kind of self calibration three-phase voltage adjusting gear comprises being wound with winding N on the iron core 1 _AB, N ' _AB, N ' _Ab, be wound with winding N on the iron core 3 _BC, N ' _BC, N ' _BC, it is characterized in that: on iron core 1, increase around winding N _Ab, on iron core 3, increase around winding N _Bc, going up mutually with BC mutually at AB simultaneously increases the twin-stage standard mutual inductor respectively and forms.

2, self calibration three-phase voltage adjusting gear according to claim 1 is characterized in that winding Nab and N ' bc series connection, and winding Nbc and N ' ab series connection constitute quadrature adjustment dish.

3, self calibration three-phase voltage adjusting gear according to claim 1 is characterized in that the twin-stage standard mutual inductor that AB goes up mutually is by adding around winding N on iron core 1 and 2 ₁₀And N ₂₀Form, the twin-stage standard mutual inductor that BC goes up mutually is by adding around winding N on iron core 3 and 4 ₃₀And N ₄₀Form, thereby constitute standard self-correcting loop.