SU964491A1 - Method of measuring static moment of electric motor - Google Patents

Description

(54) METHOD FOR MEASURING THE STATIC MOMENT

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The invention relates to a measuring technique and can be used in automatic electric drives with variable static load.

There is a known method for measuring the static moment of an electric motor by determining the difference of signals proportional to the total moment of the electric motor and the dynamic one.

This method does not provide the required measurement accuracy.

The closest to the invention in technical essence and the achieved result is a method for measuring the static moment of an electric motor, consisting in measuring the electromagnetic moment and the rotation speed of the electrode shaft, algebraically summing and then integrating the signal proportional to the integrator and subtracting from the output signal integrator signal proportional to the speed of rotation of the shaft 2. MOTOR

The disadvantage of this method is also low measurement accuracy.

The aim of the invention is to increase the measurement accuracy.

This goal is achieved in that, according to the method, a signal proportional to the difference between the integrator output signal and a signal proportional to the rotation speed of the motor shaft is used as the integrator feedback signal.

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The drawing shows a block diagram of the device that implements the proposed method.

Claims (2)

The rotor of the engine under test 1 is represented by an adder 1a, the inputs of which are supplied with an electromagnetic moment MD, proportional to the current KM Ja, where is the proportional factor IO, and some static moment MCT and the integrator 16. The main current rotor 1 is connected to the core 2 of the main current, output which 1 /, unit20 is the key to the input of a valid mathematical. Model 3 of the rotor of the engine under test 1, namely at the first input of the adder. The output of the latter is connected to the input of the integrator 39 36 of the rotor model of the engine under test 1. The output of the speed sensor 4 is the rotation of the shaft uJa ro, the test engine 1 is connected together with the speed output ujf, model 3 to the adder 5, the output of which 4 tu through regup jur 6 con {is at the second input of the adder, For. The device that implements the method works as follows. At the moment of inertia, reduced to the engine shaft, the electromagnetic moment of the engine M, and the static moment Mjjj, act. In connection with this, a signal proportional to the electromagnetic moment is sent through sensor 2 to the input of the valid mathematical model 3 of the rotor of the motor under test. If an additional signal could be determined that is proportional to the static moment of model M (, .jj and feed with the appropriate sign on the input of model 3, then the speed signal at the output of model a) d is proportional to the engine speed Shd. To get it. Such an additional signal determines the difference of the signals Da from A of the speed sensor d and the rotor model with the output of the adder 5 and is fed to the input of the controller 6. The more accurate the additional signal idop displays the magnitude of the static moment, the less the velocity mismatch D cv to D To implement the latter condition, D with through regulator 6 is fed to the input of model 3 as a negative feedback signal. connection of the integrator 36. The regulator 6 in accordance with the requirements for the dynamic accuracy of the measurement process ensures the fulfillment of the condition D co - O, with the additional signal idop. formed at the output of the regulator 6 is proportional to the static moment MQ on the shaft of the motor under test at s O and D with The invention The method of measuring the static moment | Electric motor, consisting in measuring the electromagnetic moment and the speed of rotation of the motor shaft, algebraically summing with subsequent integration of a signal proportional to the electromagnetic moment , and the integrator feedback signal and subtracting from the output signal of the integrator signal proportional to the speed of rotation shaft, characterized in that, in order to increase measurement accuracy, a signal proportional to the difference between the integrator output signal and a signal proportional to the rotation speed of the motor shaft is used as an integrator feedback signal. Sources of information taken into account in the examination 1. Measurement of the load torque of electric motors. In the book. Scientific and applied problems of power engineering, no. 4, Minsk, University of Higher Education, 1977, p. 130-133. 2. Authors svdedelstvo USSR for the application number 2781159 / 18-10 (072 696), 05.16.79 (prototype).