SU756302A1 - Power meter - Google Patents

Description

The invention relates to an apparatus for measuring power and energy in high-current pulsed electric circuits, based on the use of the ponderomotive effect of an electromagnetic field on a transmission line with subsequent conversion of pressure into a measurable signal.

Closest to the invention is a device for measuring the power of microwave oscillations in waveguides, containing a pressure sensor in the form of a piezoelectric transducer connected to a recording circuit [1].

However, this device is not suitable for energy determination and measurements in low-frequency circuits.

The purpose of the invention is to expand the functionality of the device ~ 20 VA due to the measurement of energy, as well as the possibility of measurements in low-frequency circuits.

This goal is achieved by the fact that the device introduced an additional matching element with forward and reverse conductors, and in the forward conductor located in a plane parallel to the load current conductor, the load POWER MEASUREMENT is included

2

the electrode of the piezoelectric transducer, and the measuring electrode is placed in the guard ring and consists of two parts, each connected to a recording circuit, the dimensions of the piezoelectric transducer being determined from the relation

I) - f + 2y, Λ> Τ7 _θ α 10 where C, di a is the diameter, thickness of the piezoelectric element and the speed of sound in it, respectively, F is the diameter of the measuring electrode, 1 _O th is the duration of the current pulse, and an additional a piezoelectric transducer and a target connected to the main piezoelectric transducer, mounted on an elastic element made 20 in the form of several connected ends of consoles located at equal angles to each other, and complete-. The transducer is made of piezoelectric elements connected in parallel, installed as supports under the consoles in places of maximum load on the supports, while the return conductor is designed as a symmetrical frame with a straight 30 conductor in the center of the plane.

756302

and the return conductor is fixed 'on a rigid surface, not connected with the converter.

FIG. 1 shows schematically the device, a general view; in fig. 2 location of direct and reverse conductors.

The device comprises a housing 1, a pressure sensor 2 in the form of a piezoelectric transducer with a load electrode 3, a guard ring 4 with a measuring electrode 5 divided into two parts, each of which is connected to a recording circuit 6, a matching element with a forward 7 and a reverse 8 current conductors located - in the plane parallel to the conductor 9 with the load current, the clamp 10 of the dielectric. Target. 11 with the sensor 2 pressure mounted on the elastic element 12,

'made in the form of several connected ends of consoles located at the same angles to each other. Additional piezoelectric transducer 13 is connected to the registration circuit 6, it contains connected in parallel piezoelectric elements, installed as supports under the consoles of the elastic element 12.

The device works as follows.

Between the load current Z _o in the conductor 9 and proportional to the voltage on the load current 3 ₁ in the direct conductor 7 and the load electrode 3, there is a ponderomotive force Rc, its impulse 3, which. for parallel conductors are maximum and equal

ten

15

20

25

thirty

35

ΜρΡΘ

2ΧΉ

where 1dF / 2 = N / 2 g,

B is the diameter of the loading electrode,

M = 4 £ · 1 О '^ gN / m, g is the distance between electrode 3 and the conductor 9,

B is its width

% - current pulse duration · in the load ..

In the device'M power and energy

40

45

50

This chain is determined by measuring the force P and its momentum 3 g, since

No. _ο ΐ> Θ

P-mR,

55

E - £ \ M <N-tGr <IhupZ.

'o o o

Under the action of force P load electrode 3 of the piezoelectric sensor 2 connected to the recorder 6 in the mode of the current generator, its output voltage

hook /, --E / ds'

60

where os, d, and - piezomodul, thickness and speed of sound in the piezoelectric element,

KS - chain time constant

load sensor,

P-difference of forces on the electrodes of the sensor 3 and 5,. equal to the ponderomotive force

until the elastic wave caused by its effect on the electrode 3 in the pioelectric element reaches electrode 5. After this, the registration stops. Therefore, the thickness of the sensor is selected from the condition δ 5 ία. Attaching one half of the measuring electrode 5 to the recording circuit 6 so that the condition КС ^{ζ </} ε ₀ "is satisfied ^{and the} other at CS" » _ο simultaneously register the power and energy of the current pulse in the load during the interval δΐ = because at CS" Сο

at

Sss

When the conductors 7 are combined with the load electrode 3, the temporal resolution is determined only by the electrical characteristics of the load circuit of the sensor and, when the power is changed, can reach 8 g, * КС ^а 10 "'s.

The introduction of guard ring 4 allows to reduce the measurement error due to edge effects. To eliminate distortions due to lateral unloading of the piezoelectric element 2, the width of the guard ring 4 must be no less than the thickness of the sensor 2, from where

B - f + 2 s. crea ·

In the case when the condition g>? _O and cannot be ensured due to the long duration of the 2 _O current pulse, the energy is determined by measuring the pulse of the imparted target 11 by an additional piezoelectric transducer 13. Under the action of the ponderomotive force. Maximum EMF. at the output of the additional converter 13 and, accordingly, the sensitivity is ensured by installing the piezoelectric elements of the converter as supports under the consoles of the elastic element in places of maximum load on the oyors, determined taking into account the compliance of these supports. To measure the power in this case, the piezoelectric sensor is included in the registration circuit in the charge generator mode.

To reduce. Electromagnetic

interference on the connecting wires reverse conductor 8 is in the form

symmetrical frame with direct current

65

five

756302

6

water 7 in the center of the plane (Fig. 2). So that the load acting on the return conductor 8 is not transferred to the target 11, this conductor is fixed on a rigid surface not connected with the converter. five

Constructive execution of the device provides the ability to measure the power and energy released in the load of high-current impulse electrical circuits.

Claims (4)

Claim 1. A power measurement device comprising a pressure sensor in the form of a piezoelectric transducer connected to the circuit 15 registration, characterized in that, in order to expand the functional capabilities of the device by measuring energy, as well as the possibility of measuring in low-20 frequency circuits, a matching element is introduced with the forward and reverse conductors, moreover the load current, the load electrode of the piezoelectric transducer is turned on, and the measurement electrode is placed in the guard ring and consists of two parts, each connected to a recording circuit. 2. The device according to claim 1, about t l and the fact that the dimensions Piezoelectric transducer is established from the relation O = φ 4-2 d, δϊ £ _ο 0, where 0 id is the diameter and thickness of the piezoelectric element, H) is the diameter of the measuring electrode, and is the speed of sound in the piezo element, έ _ο is the current pulse duration. 3. The device according to claim 1, characterized by the fact that an additional piezoelectric transducer is inserted and a target connected to the main piezoelectric transducer is mounted on an elastic element, the latter being made in the form of several connected ends of consoles located at equal angles to each other, and the additional transducer is from parallel-connected piezoelectric elements installed as supports under the consoles in places of maximum load on the supports. 4. The device according to PP.1, 3, characterized in that the return current lead is made in the form of a symmetrical frame with a direct current lead in the center of the plane, and the return current lead is fixed on a rigid surface that is not connected with the converter.