SU1523900A1 - Device for monitoring irregularity of air gap of electric motor - Google Patents

Abstract

The invention relates to a measurement technique and can be used to remotely measure an air gap on an operating and stopped electric machine. In order to increase the accuracy and reliability of control, a device containing four sensors 1 ₁ , ..., 1 ₄ , integrator 5, differential amplifier 19, threshold element 20 and indicator 21, introduced amplitude selectors 6, 7, differential amplifiers 8, 9, average value determination unit 10, differential amplifier 11, reference voltage source 12, correction blocks 13, 14, measuring blocks 15, 16, and indicators 17, 18. The introduction of these blocks eliminates the influence of changes in the supply voltage of the electric machine and self-checking the fault oystva. 1 il.

Description

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The invention relates to a measurement technique and can be used to remotely measure an air gap in work stations and a stopped electric machine.

The purpose of the invention is to improve the accuracy and reliability of control by eliminating the influence of changes in the supply voltage of an electric machine and the self-monitoring of device malfunction.

Pa drawing presents a block diagram of the device.

The device contains sensors, rectifiers 2, - 2 d, low-pass filters 3 f - 3jj, intermi 4i -, integrator 5, amplitude selectors 6 and 7, differential 4) amplifiers 8 and 9, unit 10 for determining the average value, differential amplifier 11 , the source 12 of the reference support of the woman, the correction blocks 13 and 14, the measuring blocks 15 and 16, the indicators 17 J 18, the differential amplifier 19, the threshold element 20, the indicator 21,

Sensors 1-14 are connected via rectifiers 2-2n and filters 3i-back to the first inputs of multipliers 4 "4i), the second inputs of which are connected to the output of integrator 5, and the outputs of multipliers 4, -4 /) are connected to the inputs of amplitude selectors 6 and /, The outputs of multipliers 6 and 7 are connected to the inputs of the differential, J-8. The outputs of multipliers 6 and 7 are connected to the inputs of the differential amplifier 9 and the input of the average value determination unit 10, the output of which is connected to the first input of the differential amplifier 11 its second input is connected to source 12 of the porous voltage} 1i, and the output - with the input of the integrator 5. The outputs of the differential amplifiers 8 and 9, respectively, through the correction blocks 13 and 14 are connected to the measuring blocks 15 and 16 and the indicators 17 and 18. The outputs of the amplitude selectors 6 and 7 are connected to the first and the second inputs of the differential amplifier 19, the output of which through the threshold element 20 is connected to the indicator 21.

The device works as follows.

Sensors 1 (- 1h are installed in diametrically opposite sides of the air gap of the electric machine and the angle between the location

The first and second pair of sensors is equal to 90 geometric degrees.

Sensors 1 - C are sent after straightening in blocks 2 f - 2 c and smoothed by filters 3 arrive at the first inputs of multipliers 4 - 44. The air gap unevenness is determined by the magnitude of the difference of signals from diametrically located sensors 14,1,2 If there is no eccentricity, then the signal difference is zero. When the rotor is displaced in the direction of some sensor, the signal in this sensor increases and the signal from the diametrically located sensor decreases. The difference between the signals is proportional to the magnitude of the signal from each sensor. For example, when increasing and decreasing the voltage of the power supply of an electro-electric machine, a change in the signal from all sensors and the differential voltage of the circuit occurs. The supply voltage may vary within t 15% of the nominal value. If the control is performed on a stopped engine, the supply voltage is applied in the range of 10-20% of the primary value. The value of the pressure in this case is chosen such that the current in the stator winding does not exceed the nominal value. Thus, the supply voltage i at the monitoring time can be 10 - 115% of nominal1 of the beginning. Accordingly, the difference between the signals from the sensors 1j - 1 may vary about 10 times. To eliminate this error, all signals are multiplied by a value proportional to the ratio between the reference voltage and the average voltage from diametrically located sensors Q and C. Therefore, the average voltage is constant and independent of the supply voltage. The appearance of the signal at the output of the integrator 5 will change the magnitudes of the signals at the outputs of blocks 4-4 / (. The difference between the reference and average voltages will decrease. The signal at the output of the integrator 5 changes to zero. After completing the qppekt signal conditioning at the outputs of blocks 4 | - 4 times the multiplier 5 sets the required signal value, and the zero value at its input.

The difference of the reduced values of the signals from the blocks 4 4 - 4/1 is highlighted by

the outputs of differential amplifiers 8 and 9. After the signals are corrected by blocks 14 and 13, the gap is measured by blocks 15 and 16.

If one of the sensors or the measuring channel is damaged, the difference in the meuf. Minimum and maximum values of w signals, respectively, from the amplitude selectors 6 and 7 will exceed the possible value in the absence of damage. The measured difference between the minimum and maximum signals from the output of the differential amplifier 19 cparavH ivetac with a valid value in the threshold element 20, the operation of the threshold element 20 is fixed by the indicator 21 in the form of a board with the inscription Malfunction.

Claims (1)

Invention Formula A device for monitoring the unevenness of the air gap of an electric machine, which contains the sensor circuit, the integrator, the first decider, the threshold element and the first differential amplifier, which is connected through the threshold element to the INPUT of the first indicator, in order to improve the accuracy and reliability , four rectifiers, four low-pass filters were entered into it, ten 15 20 25 thirty telephones, two correction blocks, two measuring blocks, the second and third sensors, the average value determination unit and the source of the reference voltage, the output of which is connected to the first input of the second differential amplifier, KOTOpoi output through the graph grader. to the pergcum inlets 1; e.romed: .geley, output of the sensor, through the sensor through successive corresponding ones; You can set a low-pass filter and a low-frequency filter to the second input, respectively; you can multiply, the outputs of the first and second multipliers are connected to the input of the third and second amplitude selectors, the outputs of which are connected to the inputs of the first and second amplifiers the differential amplifier, the outputs of the third and fourth psmsmno-J1ggeli are connected to the inputs of the digital digM of the potential uspeptel. the inputs of the average determination unit} {Achen11 and, respectively, the third and fourth inputs of a {amplitude selectors; the inputs are, respectively, nepBoi o and the second it5 are four-four multiplier, the second, third are 35 functional units and the input is corresponding to five 0 five 0 telephones, two correction blocks, two measuring blocks, a second and a third sensors, a block for determining the average value and a source of reference voltage -: the wiring, the output of which is connected to the first input of the second differential amplifier, the KOTOpoi output through the graph grader. to the pergcum inlets 1; e.romed: .geley, output of the sensor, through the sensor through successive corresponding ones; You can set a low-pass filter and a low-frequency filter to the second input, respectively; you can multiply, the outputs of the first and second multipliers are connected to the input of the third and second amplitude selectors, the outputs of which are connected to the inputs of the first and second amplifiers the differential amplifier, the outputs of the third and fourth psmsmno-J1ggeli are connected to the inputs of the digital digM of the potential uspeptel. the inputs of the average determination unit}} Achen11 and, respectively, the third and fourth inputs of the a / s advanced selectors, the output of the unit determined the average value of the connectors to the second input of the second differentiation of the amplifier, the outputs of the third and fourth differential amplifiers, respectively, of the primary and second correction blocks connected to the inputs, respectively, nepBoi o and the second it5 measure and the fourth differential amplified second and third indicators.