SU1467675A1 - Electric machine with device for diagnosing excitation winding - Google Patents

Abstract

The invention relates to electrical engineering. The purpose of the invention is to increase the accuracy of diagnosis. In an electric machine, signals from the outputs of the refrigerant temperature meters 5 at the input and output of the excitation winding I are fed to the inputs of the adder 9. The signals from the output of the adder arrive at the input of the calculator 6 of the reference resistance value Rg. The signal from the code of the resistance meter 4 - P, - and the signal from the output of the resistance calculation unit 6 P.Q are fed to the input of the comparison unit. 7. In the absence of damage to E. ("RQ. The invention allows to carry out i (L

Description

continuous monitoring. 2 Il.

1 3.p. f-ly,

  h

35

1SD

FIG.

The invention relates to the field of electric machines, more specifically to devices for protecting electric machines from damage in their windings.

The purpose of the invention is to improve the accuracy of diagnosis.

Fig. I shows a block diagram of a diagnostic device; Fig. 2 - the same, but with a power loss measuring unit in the winding.

An electric machine with a device for diagnosing damage to the excitation winding contains an excitation winding 1, a current meter 2, a voltage meter 3, a winding resistance meter 4, a refrigerant temperature meter 5 at the winding outlet, and an input 6 for calculating the reference winding resistance value, block 7 comparison, display unit 8, adder 9, which implements the calculation of the average temperature of the cooling agent, unit 10 for measuring the power loss in the winding.

The device works as follows.

The signals from the outputs of the meters 5

refrigerant temperatures at the inlet and outlet of the excitation winding 1 are fed to the inputs of the adder 9, which calculates the average temperature of the refrigerant. The signal c, the output of the adder 9, is fed to the input of the block 6 for calculating the reference value of the resistance of the winding PQ. The signal Rj from the output of the meter 4 of the winding resistance and the signal EE from the output of the block 6 for calculating the resistance of the winding are fed to the input of the block 7 of the comparison. In the absence of damage R

Since the meter 4 matches

The actual value of the winding resistance is measured, when the winding closure occurs, the output signal of the resistance meter 4 decreases by an amount equal to the resistance of the winding part that is short-circuited, and when the conductivity deteriorates, the winding will increase by the additional resistance. In block 6, the calculation is made of the resistance of the winding from the change in its temperature relative to the initial mode, so the signal at the output of the block 6 of calculation at the time of the damage of the winding does not change. Block

2

produces

constant

comparing the values of R and Rg, therefore

0

five

0

five

0

0

-

where bm and 0

damage in winding 1 will be detected immediately after occurrence. The output signal from the comparison unit 7 is output to an indication unit 8, for example, a light panel, and can be used for emergency shutdown of the machine.

The dependence of the temperature of the gas-cooled winding on the losses in it can be calculated by the expression

 K.RPOT.

gy, (, is the temperature of the refrigerant at the inlet and outlet of winding 1; RPOT power loss in

winding 1;

K - coefficient depending on the intensity of heat transfer in winding 1.

The power of losses in the winding (testing in it) is equal to the product of the current in the winding and the voltage across it, therefore the power loss measuring unit 10 in the winding 1 can also be implemented as a multiplying device on known electronic elements.

The device works in this case.

in the following way.

The signal from the output of the meter 2 of the winding 1 and the signal from the output of the meter 3 voltage on the winding I is fed to the input of the power loss measuring unit 10 in the winding 1. The signals from the outputs of the refrigerant temperature meters 5 at the output of the winding 1 and at the input to the winding 1 of the unit 10 measurements of the power losses in winding 1 are fed to the inputs of the adder 9, which calculates the temperature of winding I. The output signal from the adder 9 is fed to the input unit 6 of the calculation of the resistance of the winding 1 - F0. The signal from the output of the meter 4 of the resistance R of the winding 1 and the signal from the output of the block 6 to calculate the resistance RQ of the winding are fed to the input of the block 7 of the comparison. In the absence of damage R, Rg. Since the winding resistance meter 4 measures the winding resistance value, when a winding closure occurs, the signal at its output will decrease by an amount equal to

3,146

the parts of the winding short-circuited, and when the conductivity of the winding deteriorates, will increase by the amount of additional resistance. At the time damage occurs in winding 1, the refrigerant temperature does not change, so the signals at the output of the temperature meters 5 do not change, the signal at the output of the power changing unit 10 the loss changes by the amount of change in power of the loss in the winding caused by the appearance of damage in the winding, the signals at the output of the adder 9, and, accordingly, the resistance calculation unit 6 also change, Nako this change will be considerably less than the change in the output of the comparison unit 7 of the signal.

Thus, when a winding closure appears in the winding Rj j Rg, and when the conductivity of the winding deteriorates, Rg i R, -. Comparison unit 7 produces a constant comparison of the values of RI and R, so damage in the winding will be detected immediately after its occurrence.

A signal from the output of the comparator unit 7 is outputted to the unit for emergency shutdown of the machine.

The use of these devices for diagnosing damage to the winding will allow continuous monitoring of the technical condition of the winding and, in case of the occurrence of the diagnosed damage, will ensure the timely response of the service provider.

sonal and actuation of automatic protection of the electric machine.

Invention formula

Claims (2)

one . An electric machine with a device for diagnosing damage to an excitation winding equipped with a cooling system, containing current, voltage, and resistance measurements of the excitation winding, a unit comparing the reference resistance value with the measured one the resistance meter is connected to, and the display unit to improve the accuracy of diagnostics; two refrigerant temperature meters, installed at the inlet and outlet of the cooling system, are added, an adder, (to which the meters t mperatury), a reference value calculation unit. resistance, to the input of which the output of the adder is connected, while the output of the unit for calculating the reference resistance value is connected to the second input of the comparison unit. 2. A machine according to claim 1, characterized in that it is equipped with a power measurement unit for winding losses connected to current and voltage meters, the adder is provided with a third input to which the output of power winding losses measurement unit is connected. Phie. g