CN101710137B - Inductance and resistance compensating type capacitive voltage divider - Google Patents

Abstract

The invention designs an inductance and resistance compensating type capacitive voltage divider which is used for the measurement of nanosecond grade transient high voltage of a power pulse or power system. The voltage divider comprises a high-voltage arm and a low-voltage arm, wherein the high-voltage arm is connected with the low-voltage arm by a coaxial connecting head; a compensating inductance and a compensating resistance which are used for compensating the parasitic parameter effect of the low-voltage arm are additionally arranged on the high-voltage arm; and the low-voltage arm adopts a voltage dividing box comprising discrete components and is formed by coaxially connecting a plurality of capacitors in parallel to be placed into a metal shielding box. The invention can convert a high amplitude transient voltage signal into a low-voltage signal which can be measured by recording instruments, such as an oscilloscope, and the like in a lossless way.

Description

Inductance, resistance compensating type capacitive voltage divider

Technical field

The present invention relates to a kind of capacitive divider, be specifically related to a kind of inductance, resistance compensating type capacitive voltage divider that the nanosecond high-voltage pulse is measured that be used for that is used for pulse power or electric system.

Background technology

Be used for measure impacting high-tension voltage divider at present and mainly contain condenser type and two kinds of structures of resistance-capacitance type, although and pure capacitive divider has only amplitude error, itself has inductance capacitive divider, when measuring surge voltage, the wave head place produces the higher-order of oscillation unavoidably.Although capacitance-resistance voltage divider in parallel also can be used for the measurement of pulse voltage, capacitance-resistance commonly used voltage divider in parallel is difficult to satisfy the intrinsic standoff ratio permanence condition, has the wave form distortion problem when measuring equally.

Adopt this resistor-type compensation way of capacitance-resistance series connection dividing potential drop, damping resistance can not be excessive, excessive damping resistance can make voltage divider high frequency response variation, but little damping resistance may cause voltage divider to produce bigger wave head vibration, and the problem of frequency span still is not well solved.

Summary of the invention

The objective of the invention is to propose a kind of inductance, resistance compensating type capacitive voltage divider of widening voltage divider measurement frequency band purpose with inductance, resnstance transformer mode.

For achieving the above object, the technical solution used in the present invention is: comprise the high-voltage arm and the low-voltage arm that are connected by coaxial connector, increase the compensating inductance L in order to the parasitic parameter effect of compensation low-voltage arm on high-voltage arm ₁And compensating resistance R ₁The dividing potential drop box that low-voltage arm adopts discrete component to constitute, in the dividing potential drop box, be provided with the electric capacity that links to each other with coaxial connector, by the parasitic parameter of low-voltage arm being carried out match to the accurate measurement of low-voltage arm impedance frequency characteristic and by emulation, determine the compensating inductance and the compensating resistance of high-voltage arm, measure frequency band thereby realize widening capacitive divider.

High-voltage arm of the present invention adopts the coaxial radiation structure, the primary side conductor of high-voltage arm mediates, implant electrode is round the primary side conductor, and the distributed capacitance between the two constitutes the high-voltage arm of capacitive divider, and is cast with epoxy resin between primary side conductor and implant electrode; On high-voltage arm, increase precision resistance, high-frequency inductor coil in order to the parasitic parameter effect of the compensation low-voltage arm formation high-voltage arm compensating inductance L that links to each other with implant electrode ₁And compensating resistance R ₁The dividing potential drop box is the metallic shield box, the capacitor C of low-voltage arm ₂The coaxial parallel connection of high-frequency ceramic electric capacity of eight Da Rong values of employing is irradiation structure and is placed in the metallic shield box.

The present invention is set out by the low-voltage arm impedance frequency characteristic, determines the compensating inductance and the compensating resistance of high-voltage arm, is to realize widening the effective ways that capacitive divider is measured frequency band.In order accurately to measure and demarcate the frequency domain response characteristic of low-voltage arm, in order to determine the compensating parameter of high-voltage arm, the low-voltage arm of voltage divider has adopted discrete component to constitute the dividing potential drop box.The above design feature of dividing potential drop box can realize the accurate measurement to its impedance frequency domain characteristic, is the foundation that provides basic determined of high-voltage arm compensating element, parameter.

Description of drawings

Fig. 1 is a schematic diagram of the present invention;

Fig. 2 is the high-voltage arm structure;

Fig. 3 is the low-voltage arm structure;

Fig. 4 is the impedance frequency response measurement and the parameter fitting of low-voltage arm;

Fig. 5 is the impulse response emulation of voltage divider.

Embodiment

Below in conjunction with accompanying drawing the present invention is described in further detail.

Referring to Fig. 1, because consumed energies such as the Ohmage of dielectric polarization, electrode, shelf depreciations, the high frequency equivalent model of low-voltage arm adopts resistance R ₂, inductance L ₂And capacitor C ₂Series circuit, as shown in Figure 1.Among Fig. 1, C ₁Be high-voltage arm electric capacity, L ₁, R ₁Be respectively compensating inductance, the compensating resistance of high-voltage arm.The present invention includes the high-voltage arm and the low-voltage arm that are connected by coaxial connector, capacitor C on high-voltage arm ₁Both sides increase compensating inductance L in order to the parasitic parameter effect of compensation low-voltage arm ₁And compensating resistance R ₁, according to the physical arrangement and the frequency domain response characteristic of capacity cell, the dividing potential drop box that low-voltage arm adopts discrete component to constitute is provided with the capacitor C that links to each other with coaxial connector 7 in the dividing potential drop box ₂, by accurate measurement, determine the compensating inductance and the compensating resistance of high-voltage arm to the low-voltage arm impedance frequency characteristic, measure frequency band thereby realize widening capacitive divider.Resistance R ₂, inductance L ₂Be by capacitor C in high frequency measurement ₂The parasitic parameter of the dividing potential drop box that causes is widened the purpose that voltage divider is measured frequency band for reaching with inductance, resnstance transformer mode, and the present invention at first determines the compensating element, parameter of high-voltage arm according to Circuit theory.

According to the circuit analysis of Fig. 1, intrinsic standoff ratio β satisfies:

$\frac{1}{\mathrm{\&beta;}}=\frac{U_2}{{\mathrm{<figure-callout\; id="1"\; label="U"\; filenames="H2009102193883E00012.png,H2009102193883E00021.png"\; state="\{\{state\}\}">U</figure-callout>}}_1}=\frac{\frac{1}{\mathrm{jw}{C}_2}+\mathrm{jw}{L}_2+R_2}{\frac{1}{\mathrm{jw}{C}_1}+\mathrm{jw}{L}_1+R_1+\frac{1}{\mathrm{jw}{C}_2}+\mathrm{jw}{L}_2+R_2}---\left(1\right)$

$=\frac{(C_1-w^2{L}_2{C}_1{C}_2)+\mathrm{jw}{R}_2{C}_1{C}_2}{({\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="H2009102193883E00012.png,H2009102193883E00021.png"\; state="\{\{state\}\}">C</figure-callout>}}_1+C_2-w^2{L}_1{C}_1{C}_2-w^2{L}_2{C}_1{C}_2)+\mathrm{jw}{R}_1{C}_1{\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="H2009102193883E00011.png,H2009102193883E00012.png"\; state="\{\{state\}\}">C</figure-callout>}}_2+\mathrm{jw}{R}_2{C}_1{\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="H2009102193883E00011.png,H2009102193883E00012.png"\; state="\{\{state\}\}">C</figure-callout>}}_2}$

U wherein ₁Be the tested voltage of high-voltage arm, U ₂It is low-voltage arm dividing potential drop box both end voltage.Each element of Fig. 1 is under the situation of general value, and intrinsic standoff ratio β is a plural number, and its amplitude-frequency, phase-frequency response are all relevant with the frequency of measured signal, for realizing measurement result and frequency-independent, order:

$\frac{w{R}_2{C}_1{C}_2}{C_1-w^2{L}_2{C}_1{\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="H2009102193883E00011.png,H2009102193883E00012.png"\; state="\{\{state\}\}">C</figure-callout>}}_2}=\frac{{\mathrm{wR}}_1{C}_1{\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="H2009102193883E00011.png,H2009102193883E00012.png"\; state="\{\{state\}\}">C</figure-callout>}}_2+{\mathrm{wR}}_2{C}_1{C}_2}{{\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="H2009102193883E00012.png,H2009102193883E00021.png"\; state="\{\{state\}\}">C</figure-callout>}}_1+C_2-w^2{L}_1{C}_1{C}_2-w^2{L}_2{C}_1{C}_2}---\left(2\right)$

This moment, each circuit component of Fig. 1 satisfied:

$\frac{R_1}{R_2}=\frac{C_2}{{\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="H2009102193883E00012.png,H2009102193883E00021.png"\; state="\{\{state\}\}">C</figure-callout>}}_1}=\frac{L_1}{L_2}---\left(3\right)$

When parameter satisfied equation (3), the intrinsic standoff ratio of capacitive divider was:

$\mathrm{\&beta;}=\frac{C_1+C_2}{C_1}---\left(4\right)$

By above-mentioned analysis, when each component parameters of voltage divider satisfied (4), its intrinsic standoff ratio β was a real constant, is the ratio of height pressure arm capacitance sum with high-voltage arm appearance value.Can realize the frequency-independent of measurement result and measured signal, thereby widen the measurement frequency band of capacitive divider greatly, the harmless low voltage signal that high amplitude transient voltage conversion of signals is become register instruments such as oscillograph can measure.

Referring to Fig. 2, high-voltage arm of the present invention adopts the coaxial radiation structure, the primary side conductor 1 of high-voltage arm mediates, implant electrode 2 is round primary side conductor 1, distributed capacitance between the two constitutes the high-voltage arm of capacitive divider, and is cast with epoxy resin 4 between primary side conductor 1 and implant electrode 2; Precision resistance 5, high-frequency inductor coil 6 link to each other with implant electrode 2 and constitute high-voltage arm compensating inductance L ₁And compensating resistance R ₁Capacitive divider is by bonding shell 3 ground connection.

Referring to Fig. 3, the capacitor C of low-voltage arm of the present invention ₂The coaxial parallel connection of high-frequency ceramic electric capacity (8) of eight Da Rong values of employing is irradiation structure and is placed in the metallic shield box 9.

Fig. 4, the 5th, the impedance frequency response measured result of low-voltage arm dividing potential drop box.Can carry out the match of low-voltage arm parasitic parameter according to measurement result, determine to provide foundation for the high-voltage arm compensating parameter.Carry out parameter fitting according to Fig. 4 measurement result, the polyphone equivalent resistance: 0.03 Ω, polyphone equivalent inductance: 0.7nH.

Claims (3)

1. an inductance, resistance compensating type capacitive voltage divider is characterized in that: comprise the high-voltage arm and the low-voltage arm that are connected by coaxial connector (7), increase the compensating inductance (L in order to the parasitic parameter effect of compensation low-voltage arm on high-voltage arm ₁) and compensating resistance (R ₁), the dividing potential drop box that low-voltage arm adopts discrete component to constitute, in the dividing potential drop box, be provided with the electric capacity that links to each other with coaxial connector (7), by the parasitic parameter of low-voltage arm being carried out match to the accurate measurement of low-voltage arm impedance frequency characteristic and by emulation, determine the compensating inductance and the compensating resistance of high-voltage arm, measure frequency band thereby realize widening capacitive divider.

2. inductance according to claim 1, resistance compensating type capacitive voltage divider, it is characterized in that: said high-voltage arm adopts the coaxial radiation structure, the primary side conductor (1) of high-voltage arm mediates, implant electrode (2) is round primary side conductor (1), distributed capacitance between the two constitutes the high-voltage arm of capacitive divider, and is cast with epoxy resin (4) between primary side conductor (1) and implant electrode (2); Precision resistance (5), high-frequency inductor coil (6) link to each other with implant electrode (2) and constitute high-voltage arm compensating inductance (L ₁) and compensating resistance (R ₁).

3. inductance according to claim 1, resistance compensating type capacitive voltage divider, it is characterized in that: said dividing potential drop box is metallic shield box (9), and low-voltage arm adopts the coaxial parallel connection of high-frequency ceramic electric capacity (8) of eight Da Rong values to be irradiation structure and is placed in the metallic shield box (9).

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