RU27230U1 - PIEZO ELECTRIC SENSOR - Google Patents

Abstract

A piezoelectric current sensor comprising a winding and a piezoelectric system, characterized in that the piezoelectric system includes a piezoceramic plate with metal electrodes placed between two dielectric plates, the device further comprising a core connected to the winding, in the gap of which a piezoelectric system is placed.

Description

The utility model relates to measuring technique and can be used to measure pulsed and alternating currents in electrical devices.,

The most effective utility model can be applied in the field of electronic technology related to the development of powerful high-voltage devices containing magnetic elements (ME) with a gap.

Known SI current sensor containing a measuring transducer, a piezoceramic membrane with a mirror coating, a lens, a fiber optic communication channel, AC and DC amplifiers, divider, capacitance, adder, shutter

with a variable transmittance, a registrar and designed to measure direct and alternating currents. The disadvantages of the known device include:

- a pronounced effect of temperature on the magnitude of the angle of the Faraday rotation, which is associated with a change in the optical and magnetic properties of the material of the magneto-optical element at significant temperature differences,

-high structural complexity, the presence of a number of responsible functional evils,

-the need to install around the element of the electric circuit with the measured current of an additional coil from the fiber,

low reliability

-large mass and high cost.

The task to which the creation of the proposed device is aimed is to simplify the process of monitoring the current value in high-power high-voltage devices, to minimize the amount of active losses caused by the measurement process, and to improve. accuracy of measurements.

The problem is solved in that in a piezoelectric current sensor containing a winding and a piezoelectric system, said piezoelectric system includes a piezoceramic plate last with metal electrodes placed between two dielectric plates, the device further comprising a core connected with the winding, in the gap of which is placed piezoelectric system.

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Figure 1 shows a schematic illustration of the design of a piezoelectric current sensor (PDT).

Figure 2 presents an electric circuit illustrating the measurement of current using the proposed. PDT. -. ..

PDT contains a winding-1, a core consisting of two ferrite cups 5. The piezoelectric system, which is located. on in the core gap. (between ferrite cups 5), includes a piezoceramic plate 2 with metal electrodes 3, placed between two dielectric plates 4. G ferrite cups 5 tightly compress the piezoelectric PMT system using a coupler 6.

The proposed MPT works as follows.

When an alternating or pulsed current flows through winding 1, a compression curve F acts on the piezoceramic plate 2 with the frequency of the flowing electric current. Due to the direct piezoelectric effect, the mechanical stress applied to the piezoelectric ceramic plate 2 leads to the appearance of an electric charge on its plates proportional to the value of the current passing through the winding 1 electric current. Received the electric potential is fed to the output of the piezoelectric current sensor 12 ,. affects the input of the scaling amplifier 13 s

high input impedance (for example, 140 UD17A) and amplified to the required value. The scale of the output signal is set by changing the value of the resistances of the resistors 7,9,10,

eleven. . -. .;

In Fig. 3, an example of the use of PDT in a current stabilization circuit is presented.

A voltage proportional to the measured current is supplied from the output of the inverter 12 to the input of the comparator 14. When the set voltage (Usad) is reached, the comparator 14 is activated and generates a signal for the control circuit 15, which either limits the current level of the control object 16, or, due to exceeding the permissible current regulation object 16, gives a trip signal.

The proposed PDT greatly simplifies the monitoring of the measured value of the electric current, because the gap with the gap (transformer or throttle made on an armored core of type B or Kv) can be used. In addition, the PDT has a high noise immunity, since the voltage levels are proportional to the measured current from the output

PDT are measured in volts and tens of volts, and the scaling amplifier has a large common-mode signal attenuation coefficient (Kos 100 dB).

Also, a small error - the conversion of mechanical stress into an electric charge (about 0.0001%) ultimately increases the accuracy of the current measurement offered by the piezoelectric current sensor. . Yosh

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Sources of information

1. RF patent N 2171996, cl. G 01 R 19/00, 15/24, publ. 08/10/2001, BIPM N 22 (prototype)

2.Vigleb G. Sensors. Device and application M .: Mir, 1989. - 196 p., Ill.

3.Dragomirov S.G. Modern and perspective directions of development of automotive electrical equipment and electronics // Autotractor electrical equipment, 2001,

N 3-4, p. 4

Claims (1)

A piezoelectric current sensor comprising a winding and a piezoelectric system, characterized in that the piezoelectric system includes a piezoceramic plate with metal electrodes placed between two dielectric plates, the device further comprising a core connected to the winding, in the gap of which a piezoelectric system is placed.