SU1465829A1 - Method of locating turn shorts in armature winding of electric machine - Google Patents

Abstract

The invention relates to electrical measuring technology and can be used to detect inter-turn shorts during tests of winding insulation of Korean coil collector electrical machines. The purpose of the invention is to increase the reliability of control - achieved by providing the possibility of reliable detection of a WIDTH closure through high values of resistance (more than 10 ohms). The method is based on research, - the character of the change in the damped transition process in the tested winding pulsed test voltage. A device that implements the method contains a generator of 1 test pulses, a comparator 2, counter-drivers of 3.4 and 5 pulses, selective blogs 6 and 7, a voltmeter 8, a switch 9, a meter 10 phase difference. Generator D includes between the corresponding collector plate of the core of the tested electric machine 1I and the housing. A measurement circuit containing the elements listed above is connected to two adjacent collector plates. 2 Il. § (L

Description

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The invention relates to electrical measuring technology and can be used to detect roll closures during tests of winding insulation of Korean coil of collector electrical machines.

The purpose of the invention is to increase the reliability of the control by providing the possibility of reliable detection of the WIDTH closure through high resistance values (more than 10 ohms).

FIG. a diagram of the device that implements the proposed method; Fig. 2 shows time diagrams of voltages in the presence of a loop closure in the winding of the core.

The device, realizing the method, contains a test pulse generator -1, comparator 2, first 3, second 4 and third 5 pulse shapers, first 6 and second 7 redundant blocks, voltmeter 8, switch 9 and meter 10 phase difference. The generator 1 is connected between the corresponding collector plate of the core of the electric machine 11 being inspected and the housing, a measuring circuit containing the listed elements

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cops, connected to two nearby adjacent plates of co.plektora.

The proposed method is based on the study of the nature of the change in the decaying transient process in the tested winding, which occurs when the test object is subjected to a pulse test, by converting said transient process into a discontinuous sequence of pulses comparing it with the corresponding exemplary pulse sequence and evaluation of the results of this comparison of the presence of a coil closure in the winding. When comparing sequences of pulses, the effect is used, which concludes that 1 — violation of the equality of time intervals in the presence of winding closures at least between two pulses, sharply distorts the amplitude spectrum of the compared intermittent pulse sequence; as a result, zeroes disappear (harmonics with zero amplitude), defined by time intervals m: izvdu appropriate impulses; the harmonic, having previously (in the absence of closures) zero amplitude, acquires a certain value of amplitudes), by which | and is determined by the value W of the defect s 1 winding,

The proposed method is: 1 exists as follows. ;, Impulse test voltage is applied from the generator with the corresponding collector plate and core box. The front edge of the test pulses excites the high-frequency detonating process (Fig 2a) in the washing. The voltage of the high-frequency damping process is removed from two adjacent collectors: the plates adjacent to the test voltage applied. The voltage from the indicated plates is fed to the inputs of the shaping counters 3-5 and the input of the comparator 2. When the measured voltage is equal, the response threshold to the Jnop controller last generates a pulse (FIG. 26) that triggers the input. 3 pulses, which, when the voltage passes through zero, generates three pulses (Fig. 2b) 5 which specify the beginning of the measurement process from the third positive half-wave. After forming the third pulse

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five

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five

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counter driver 3 generates at its output a trigger pulse (fig. 2d) arriving at the input of start counter generator 4, which generates four pulses at times of transition of the measured voltage through zero (from negative values to positive) that make up the compared intermittent pulse sequence (Fig. 2d), as well as a start-up pulse (Fig. 2e) arriving at the input of the start of the forming counter 5. The specified forming counter forms four pulses at the moments of transition of the measured voltage through ul, corresponding .stvuyuschih prershistuyu sequence (2g). The time intervals between the pulses in this sequence are equal and do not depend on the presence of a defect. From the information outputs of the formers-counters 4 and 5, the impulsive pulse sequences arrive at the inputs of the electoral blocks 6 and 7. The switch 9 connects the voltmeter 8 to the output of block 7. Simultaneously change the frequency of the block 7 and, according to the indication of the voltmeter Sj, adjust the follow-up period pulses, find the first zero of the amplitude spectrum of an exemplary transient sequence of pulses. Switch 9 connects the voltmeter 8 to the output of the tamper unit 6 and, by difference from the zero level of the amplitude of the selected harmonic, it is judged that there is a trigger.

Both pulse sequences (comparable and exemplary) can be formed not only when the measured voltage across the zero goes from positive values to negative, significant and vice versa, from negative to positive values. LL of this counter-formers 4 and 5 are set to the appropriate mode of formation of pulses.

If the coil closure is detected by the indication of the voltmeter 8, then by changing the tuning frequency according to the meter 10 measurement of the phase difference, find the number of harmonics that coincide in phase or are counter-38 "By this number and value of the voltmeter 8 is determined place of defect.

The invention detects the sensitivity of the method, as a result of which it is possible to reliably detect a loop through resistance of more than 10 ohms.

Claims (1)

Invention Formula The method of detecting the winding closure in the winding of the electric machine core, based on the supply of a pulse voltage between the collector plate and the core case and measuring the voltage on two adjacent collector plates, is different from that 5 in order to increase the sensitivity at the moments of transition of the indicated voltage across zero from negative values to positive or, conversely, form positive impulses, forming a comparable and exemplary peristrious sequences of impulses with what; . tympm impulses in each, and compared preritta sequence. the pulses are formed starting from the third positive half-wave of the measured voltage, and an exemplary intermittent pulse sequence is formed after the end of the compared intermittent pulse sequence, and, in addition, the harmonic corresponding to the first zero amplitude spectrum of the specified pulse sequence is extracted from the sample broken pulse sequence from the compared perverted pulse sequence a harmonic with a number corresponding to the first zero amplitude spectrum by Vista prery0 exemplary pulse sequence, and a difference of harmonics tlitudy this zero value is judged on the coils ohm circuit. 1 and Vnap o and ABOUT and ABOUT but about and about and 2 - /