SU1335881A1 - Arrangement for determining mechanical parameters of electric machines - Google Patents

Abstract

The invention relates to the field of measuring the mechanical characteristics of electrical machines. The purpose of the invention is to expand the functionality by providing the ability to measure the electromagnetic moment and the power of the machine. The device contains two oppositely included sections 3 and 4 of the auxiliary winding, which were placed into the pole shoe of the machine with a step proportional to the width of the tooth or the groove of the core. The sections are arranged symmetrically, with respect to the pole axis, at a distance from each other, a multiple of the size of the toothed step. A frequency meter 7 and a voltage meter 8 are connected to the winding outputs, the outputs of which are connected to the multiplication unit 9. 4 il. , 7 X en CO with SL 00 00 S

Description

one

The invention relates to the field of measurements of mechanical parameters of electric, direct current machine machines and can be used in systems of direct current electric drive.

The purpose of the invention is to expand the functional capabilities of the device.

Figure 1 shows the structure of the auxiliary winding and its location in the pole shoe of the DC machine; figure 2 - the distribution of the magnetic induction of the harmonic harmonic and the resulting VAT core and main poles without taking into account the serration of the core; FIG. 3 shows the distribution of the resultant induction of the magnetic field in the air gap of the DC machine, taking into account the serration of the core; 4 is a block diagram of a measuring device.

1. schematically depicts a pole 1 of a direct current machine, a gear bar 2 and an auxiliary winding consisting of sections 3 and 4, connected in opposite directions. Section conductors are located in longitudinal grooves made on the side of the pole shoe facing the core. Distance

13

between the grooves belonging to one section is equal to half of the tooth pitch t (y, t / 2. The distance between the sections placed symmetrically with respect to the axis of the pole, in terms of the size of the tooth

steps at Kt, where K is the coefficient of pro., c of its shaft is proportional to the magnitude of the measured voltage and the frequency of the auxiliary winding voltage

portionion. I.

The reaction of the core in a direct current machine distorts the initial distribution of the MDS of the main poles in the gap of the machine, amplifying it under one edge of the pole and weakening under the other. The distribution of the resulting 1ODS core and main poles in the gap of the DC machine without taking into account the serration of the core is shown in Fig. 2 (curve 5). The amplitude of the magnetic induction of the tine harmonic MDS depends on the size of the resultant MDS of the machine that falls on the air gap and the dentate layer. The distortion of the resulting MDS under load leads to a corresponding distortion of the distribution of the prong harmonic MDS (curve 6).

If we take into account the serration of the machine core and neglect the saturation of electrical steel, the distribution of the resultant induction of the magnetic field in the air gap of the stationary

-

yu 15

oh oh

3358812

current has the form of a curve shown in FIG.

When the core rotates in sections of the auxiliary winding from the magnetic field of the harmonic magnetic field, the EMF is applied. When the current cor is equal to zero, i.e. without distortion of the magnetic field, the resulting EMF of the two sections of the auxiliary winding, which are connected in opposite, is equal to zero. With an increase in the current of the core, which at a constant excitation current of the machine characterizes the magnitude of the electromagnetic moment, the value of the emf of the auxiliary winding also increases. Therefore, the EMF value of the auxiliary winding is proportional to the electromagnetic moment of the direct current machine.

The frequency of the auxiliary winding EMF depends on the number of teeth (grooves) of the core and its rotation frequency, i.e. The frequency of the variable EMF of the auxiliary winding for this electric machine is proportional to the frequency of rotation of the shaft.

By measuring the frequency f and the voltage of the EMF and auxiliary winding, it is possible to determine the electromagnetic power of the machine. Electromagnetic power

0

25

P ,, Electromagnetic moment of the machine

direct current to rotation frequency

measured voltage and auxiliary winding voltage frequency

m, s, and f

Consequently, the electromagnetic power of the direct current machine is proportional to the product of the measured frequency and the emf auxiliary, winding

P, M-U f.

To determine the electromagnetic power of a direct current machine, the measuring device (Fig. 4) contains frequency measurement units 7 and voltages 8, the inputs of which are connected to the coil winding, and the outputs to multiplication unit 9.

The signal at the output of the multiplication unit is proportional to the electromagnetic or mechanical power of the machine.

Claims (1)

Invention Formula A device for determining the mechanical parameters of electrical ma 13-1588 DC busbars containing an auxiliary winding, designed for laying in the pole shoe of the machine, and a measuring device, characterized in that, in order to expand its functionality, the auxiliary winding is made of two sections, which are connected in opposite directions and are designed to be located symmetrically relative to one the pole axis along the edges of the pole shoe surface facing the bark, at a distance from each other, is a multiple of the tooth pitch, and the measuring device is made up of multiplying blocks and frequency and voltage measuring blocks, whose inputs are connected to the auxiliary winding, and the outputs are to the input of the multiplication unit. Thebes.2. FFG.Z Editor P.Geershi Compiled by S. Shutove Tehred V. Kadar Order 4043/38 Circulation 730 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., d. A / 5 Production and printing company, Uzhgorod, st. Project, 4 Proofreader L. Pilipenko