SU1183929A1 - Apparatus for determining electric machine run out time - Google Patents

Abstract

A DEVICE FOR DETERMINING THE ELECTRIC MACHINE RUNNING TIME, containing a switch designed to connect the coil of an electric coasting machine to a series-connected amplifier, limiter, differentiator and pulse driver, the output of which is connected to the first input of the And element, whose output is connected to the first input of the unit measuring time intervals, about the fact that, in order to increase accuracy, it is equipped with first and second pulse counters, a reference clock generator and the trigger, the first pulse counter is connected between the output of the pulse former and the element I, and the second pulse counter is connected to the output of the pulse former, while the second inputs of the pulse counters are connected to the output of the frequency generator I and the output of the second pulse counter is input ( L trigger and the second block input is measured by time intervals, to the first input of which the output of the element I is connected, the second input of which is connected to the output of the trigger. 00 with about

Description

The invention relates to electric machines, namely, devices for determining the time over which the rotor speed varies from within the range from the maximum fixed value to the minimum fixed value when the power of the electric machine is turned off. By the run time, the condition of the bearing support of the electric machine is indirectly estimated. The purpose of the invention is to improve the accuracy of determining the run-out time of an electric machine by increasing the accuracy of determining the fixed rotor speed of an electric machine and stable allocation of the time point corresponding to the fixed rotor speed of the electric machine. with. . FIG. 1 shows a block diagram (The proposed device, FIG. 2, 1 Fig. 1, voltage at different points. The device includes a power supply unit t, an amplifier 2, whose input is connected to the winding of an electric machine 4 via the switch 3 to the winding of the electric machine 4. Amplifier output 2 is connected to the series-connected limiter 5, di4) by the factorizer 6, shaper of 7 P1 pulses. The first 8 and second 9 counters of the first inputs are connected to the output of the driver 7 pulses, and the second to the generator 10 of the reference frequency. The device also contains an element 11, the first input of which is connected to the output of the first counter 8, a trigger 12, the input of which is connected to the output of the second counter 9, and the output to the second input of the element 1 and the time interval measuring unit 13, the first input of which is connected to the output element 11, and the second to the output of the second counter 9. The device operates as follows. Switch 3 connects the electric machine 4 to the power supply unit 1 in the Acceleration mode. After the electric machine sets 4 nominal speeds, switch 3 disconnects power supply 1 from electric machine Hb1 4 and connects the input of amplifier 2 to its winding. After disconnecting electric machine 4 from power supply 1, an emf is induced in its winding (ph:% 2a) from the residual magnetization . The induced voltage of the EMF is amplified by amplifier 2 (Fig. 26) and normalized in amplitude (Fig. 2s) by limiter 5. Next, the signal, normalized in amplitude by limiter 5 with steep fronts, is fed to the differentiator 6, which generates short alternating pulses at transition times bounded sine wave through zero (Fig. 2B). The pulse shaper 7 forms short rectangular pulses of positive polarity (Fig. 2d) at the time corresponding to the front of positive pulses from differentiator 6. These pulses are the first 8 and second 9 counters are set to zero. The second inputs of counters 8 and 9 receive pulses (Fig. 2 (9) from the reference frequency generator 10. Counters 8 and 9 calculate them in the time interval between the pulses coming from the imager 7. As soon as the pulse duration from the imager 7 reaches the value equal, where N is the counting factor nejJBoro of the counter 8, and T is the follow-up period, generator pulses 10 is the reference hour, tots, the output of the first counter 8 {pulses are formed (Fig. 2d), which, through the element 11, goes to the unit start-ups 13 time interval measurements. Block The time interval measurement starts counting (Fig. 2i). As soon as the pulse period from the imaging unit 7 reaches a value equal to NjT, where NT is the counting factor of the second counter, the output of the second counter 9 forms a pulse (Fig. 2), which sets the trigger 12 is in the inverse state (Fig. 2), whereby the And 11 element is closed at the second input and stops counting the time interval (Fig. 2 and), arriving at the second input of the time interval measuring unit 13. The time interval measurement unit 13 measures the time interval from the moment the pulses arrive at it from, the first counter to the moment the pulse arrives from the second counter. All blocks of the device are made on standard elements. Amplifier 2 is made on the 140UD 8 operational amplifier 8, and limiter 3 is made on the 1.40UD1A type operational amplifier, which provides steep fronts of a limited sinusoidal signal. The differentiator is a differentiating chain. The shaper 7 pulses are made on a 155AGG one-shot, which produces the formation of short-duration pulses and matches the output of the analog stages with the input of the stages collected on the digital IC of the 155 series. Counters 8 and. 9 pulses are made on the basis of binary decade counters 155IE2 and logical MMS 155LA2. The reference frequency generator 10 is assembled on an IML 155LAZ with a 94 MHz quartz resonator in a feedback circuit. Element K 11 is made on the IC 155LAZ, trigger 12 on the IC 155TM2, and the block for measuring time intervals on the IC 155LAZ, 155IE2, 514ID2 and the ALS324B LED indicators. The proposed device, in comparison with the known, has a high accuracy of determining the run out time. an electric machine due to the precise determination of the upper and lower fixed frequencies of the stable timing of the moment of time corresponding to the achievement by the rotor of fixed rotational frequencies.

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Claims (1)

DEVICE FOR DETERMINING ELECTRIC MACHINE CURRENT TIME, comprising a switch for connecting the winding of an electric coast-running machine to a series-connected amplifier, limiter, differentiator and pulse shaper, the output of which is connected to the first input of the element And, the output of which is connected to the first the input of the unit for measuring time intervals, about. which, in order to increase the accuracy, is equipped with a first and second pulse counters, a reference frequency generator and a trigger, the first pulse counter being connected between the output of the pulse shaper and the element And, and the second pulse counter connected to the output of the pulse shaper, this, the second inputs of the pulse counters are connected to the output of the reference frequency generator, and the output of the second $ g pulse counter is connected to the trigger input and the second input of the time interval measuring unit, to the first input of which the output of the AND element, the second input of which is connected to the trigger output, is switched off. SU „„ 1183929 1 .