SU1557621A2 - Device for determining heating of synchronous electric machine - Google Patents

Abstract

The invention relates to electrical engineering, mainly to synchronous machines. The aim of the invention is to improve the accuracy and reliability of the device. The goal is achieved by converting the output signals of sensors 4, 3, 8 taking into account their effect on the magnitude of the electromagnetic losses at nonlinearity of the idling characteristics of the machine, are summed and fed to the input of the inertial link 2. The output signal of the device corresponds to the heating of the machine and is intended for use in signaling, mode control or protection schemes. 1 il.

Description

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The invention relates to electrical engineering, preferably asynchronous machines, and is a further invention to the device according to author, no. 1274057.

The purpose of the invention is to improve the accuracy and reliability of the device for determining the heating of a synchronous electric machine.

The drawing shows a diagram of a device for determining the heating of a synchronous electric machine.

The device contains an adder 1 and an inertial link 2 connected to it, as well as a sensor 3 of the stator winding voltage of a synchronous machine, a reactive current sensor 4 of the stator winding of a synchronous machine, the first 5 and second 6 quadrants, and a unit 7 of the multiplier 8 active current sensor the stator of the synchronous machine and the third quadrant 9. The input of the second multiplication unit 10 is connected to the input of the first quadrant 5, the input of the fourth quadrant 1 is connected to the output of the second quadrant 6, The device is designed as follows.

The first input of block 7 is multiplied and the first quad 5 is connected to the reactive current sensor 4, the output of which is connected to the input of the adder 1. The second input of the multiplication unit 7 and the second quad 6 are connected to the voltage sensor 3 and the output of the sub keys to the adder input 1. The output of multiplication unit 7 is connected to the adder 1. To the reactive current sensor 4 and the second quadrant 6 are connected the inputs of the second multiplication block JO, the output of which is connected to the adder 1, and the output of the fourth quadrant b connected to the output of the second quadrant b which subkey n 1 to the adder 8 to the sensor active current third squarer 9 is connected, whose output is connected to the adder 1. The adder output is connected to one input of inertial rnnogo link 2.

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The device works as follows.

The signal from the output of the reactive current sensor 4 is fed to the input of the first quad 5, and the passage through it is squared so that the signal from the output of the first quad 5 to the input of the adder 1 is proportional to the loss component

in a synchronous machine, depending on the square of the reactive current.

The signal from the output of voltage sensor 3 is fed to the input of the second quadrant 6, and the passage through it is squared, as a result of which the signal coming from the output of the second quadrant 6 to the input of adder 1 is proportional to the loss component in the synchronous machine depending on square voltage on the stator.

At the same time, the signals from the output of the reactive current sensor 4 and the voltage sensor 3 are fed to the corresponding inputs of multiplication unit 7 and, passing through it, are multiplied, resulting in a signal from the output of multiplying unit to the input of adder 1 proportional to the component of the losses in the synchronous machine depending on the product of the reactive current and the stator voltage.

The signal from the output of the active current sensor 8 is fed to the input of the third quadrant 9, and the passage through it is squared, as a result of which the signal from the output of the third quadrant 9 to the input of the adder 1 is proportional to the component of the loss in the synchronous machine, depending on the square active current.

At the same time, the signals from the output of the reactive current sensor 4 and the second quadrant 6 are fed to the inputs of the second multiplication unit 10, the passage is multiplied alternately, and the signal from the output of the multiplication unit to the input of the adder 1 is proportional to the loss component the machine, depending on the product of the reactive current and the square of voltage on the stator: the signal from the output of the second quadrant 6, proportional to the square of the voltage of the stator, is fed to the input of the fourth quadrant 1, and the passage through it is raised to kVA therefore, the signal from the output of the fourth quadrant 11 to the input of the adder 1 is proportional to the component of the losses in the synchronous machine, depending on the fourth degree of voltage on the stator. The adder 1 performs the summation of the signals from the outputs of the quadrants 5, 6, 9 and AND and multiplication blocks 7 and 10, which are proportional to the corresponding loss component.

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The signal from the output of the adder I is fed to the input of the inertial link 2, which is essentially a thermal model of the synchronous machine, so that the output signal of the inertial link 2 is proportional to the heating of the synchronous machine caused by the presence of electromagnetic losses in it. If it is necessary to take into account the effect of ventilation losses on heating the machine, they can be taken into account by applying an appropriate additional signal of a constant value to the input of summat.ra.

The output signal of the proposed device, depending on the purpose and specific conditions of use of the synchronous machine, can be used to feed a measuring device for the visual observation of heating, as well as to feed an automatic control system and limit the load conditions of the synchronous machine or relay circuit. protection, acting on the warning signaling, or on disabling

The technical advantage of the proposed device is that the determination accuracy of the heating becomes higher, as a result of which the proposed device provides more reliable information about the temperature violation than the prototype, and allows you to take the necessary measures in a timely manner, which increases the reliability of the machine.

A positive effect is achieved due to the fact that in the proposed device a more complete consideration of the factors influencing the heating of the machine is carried out.

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The output signal of the proposed device may be polio signaling circuits, protection circuits and automatic control circuits.

Since the proposed device provides a more accurate following of its output signal overheating the machine, it creates the possibility of more complete use of power electrical equipment and at the same time increases the reliability and durability of its work due to the possibility of more timely taking the necessary measures based on more reliable information,

The technical readiness of the proposed device for use in the national economy lies in the fact that it can be easily realized on the basis of standard elements (for example, on the basis of a unified block control system or on commercially available integrated circuits).

Claims (1)

Invention Formula A device for determining the heating of a synchronous electric machine according to ed. If 1274057, characterized in that, in order to increase accuracy and reliability in operation, The fourth quadrant and the second multiplication unit are added to it, the outputs of which are connected to the corresponding inputs of the adder, the first input of the second multiplication unit is connected to the output of the reactive current sensor of the stator winding, and its second input is connected to the output of the second quadrant and the fourth quadrant input.