SU1513376A1 - Device for measuring temperature of winding of electric motor - Google Patents

Abstract

The invention relates to a measurement technique and makes it possible, using relatively simple technical means, to achieve high accuracy in measuring the temperature of windings of electric machines, for example, rotors of synchronous generators and motors. The device contains a measuring shunt 1 included in the power supply circuit of the winding 2, a low-resistance 3 and a high-resistance 4 resistors and a tracking system consisting of a reichord 5 with a series-connected exemplary resistor 6, a zero amplifier 7 and a reversing motor 8. The ratio of the resistance of the reichord 5 and the exemplary the resistor 6 is taken to be equal to the product of the temperature coefficient of resistance of the winding 2 by the specified temperature measurement range. 1 il.

Description

the sensor 2, the voltage divider, oGpa-15. is fixed by an arrow of a reohord 5. Caused by series-connected low-resistance 3. and high-resistance 4 resistors, a reohord 5, an exemplary resistor 6, a differential amplifier 7, a reversing motor 8.

Reohord 5, differential amplifier 7 and reversing motor 8 are components of a standard automatic follower device, thanks to the specified ratio of resistances of the reichord 5 and the exemplary resistor 6, the relationship between the displacement of the reichord slider 5 (the arrow 20 of the instrument) and the temperature increment of the end coil 2 is linear.

To eliminate the influence of the resistance of the wires of the power circuit of the winding 2 on the measurement accuracy

balancing, for example, the electron shunt 1 is connected directly

fixed by the arrow of the reichord 5. When

due to the above ratio of resistances of the reichord 5 and the model resistor 6, the relationship between the displacement of the slider of the relay 5 (instrument arrows) and the temperature increment of the winding 2 is linear.

To eliminate the influence of the resistance of the wires of the power circuit of the winding 2 on the measurement accuracy

thirty

automatic potentiometer type KSP or CAT.

Winding i and measuring shunt 1 connected in series with the power supply circuit form one of the two branches of the dc measuring bridge, the second branch of which is formed by resistors 3 and 4, having the same temperature coefficient of resistance.

The exemplary resistor 6 is made of the same wire as the rheochord 5, with the resistance ratio of the rheochord 5 and the resistor. 6 is equal to the product of the temperature coefficient of resistance of the winding resistance to the specified temperature range, i.e. the increment of the resistance of the winding to its nominal resistance at the initial value of the measured temperature 45.

The device works as follows.

At a set temperature of 35

The operation of the electric machine is due to the Q-controlled winding and

the measuring bridge is in balance. At the same time, the potential at the connection point of resistors 3 and 4 is equal to the potential on the slider of a reichord 5.

With a change in the temperature of the winding 55 gatel, whose shaft is kinematically

associated with the engine, the ohmic resistance changes, which in turn causes a change in the potential on the slider of the reichord 5. The resultant

This is due to the fact that, in order to increase the measurement accuracy and simplify the device, about

To the current collector brush 10, the series-connected rheochord 5 and the exemplary resistor 6 with low-resistance wires are connected directly to the terminals of the shunt 1. To reduce the impact of the sliding contact, the brush-ring on the measurement accuracy of the resistor 4 can be connected to the current collector ring 9 additional brush 11. 1With such a connection, the resulting error in measuring the temperature of the winding will practically be determined by the accuracy of the fitting of the resistance of the reference resistor 6 relative to the resistance events of a reochord 5.

Formula of invention

A device for measuring the temperature of the winding of an electric machine, which contains a resistive voltage divider connected in parallel to the power source and a series measuring shunt, a reohord, an amplifier whose first input is connected to the rheochord engine and connected to the output of a reverse motor that is connected to the power supply. To increase the measurement accuracy and simplify the device, about it is entered into 531313376

a ratios resistor, a serial shunt, and the second input is connected to a resistor and an exemplary resistor connected to the output of a resistor connected in parallel with the measured-. go divider voltage.

Claims (1)

Claim A device for measuring the temperature of the winding of an electric machine, containing a resistive voltage divider connected in parallel to a power source and connected in series to a controlled winding and a measuring shunt, a reochord, an amplifier, the first input of which is connected to the rechord engine, and a reversible motor connected to the output of the amplifier, the shaft of which is kinematically connected with a rechord engine, characterized by the fact that, in order to increase the accuracy of measurements and simplify the device, a standard resistor was introduced into it, after ovatelno connected slidewire and exemplary resistor connected in parallel measurable telnomu shunt and the second amplifier input coupled to an output of a resistive voltage divider ·.