SU1164667A1 - Device for monitoring parameters - Google Patents

Abstract

A PARAMETER MONITORING DEVICE, containing a sawtooth voltage generator, connected by an output to a peak detector input connected by an output to a control input of a bandpass filter unit, a voltage pulsation sensor, an indication unit that, in order to expand the field of application, A reverse pulse counter, a controlled pulse generator, a notch filter, an adder, first and second comparators, first, second and third keys, first, second and third integrators, first and volts oy delay elements. the first and second elements AND, the OR element and the pulse generator connected by an output to the summing input of a reversible counter and to a single trigger input connected by a zero input to the zeroing input of a reversible counter and the output of the first delay element, and direct and inverse outputs to the control inputs of the first and second keys, respectively, and to the first inputs of the first and second And elements, respectively, connected to the outputs of the first and second comparators, respectively, and outputs to the inputs The OR input connected with the input of the first delay element, with the subtracting input of the reversible pulse counter and through the second delay element with the control inputs of the third keys connected to the outputs through the corresponding first integrators to the inputs of the display unit, and the inputs to the corresponding inputs of the control panel filters and to the corresponding inputs of the adder, connected to the output with the inputs of the first and second switches connected by the outputs to the inputs of the second and third integrators, respectively, output outputs, respectively, with the first and second inputs of the nejjBoro and the second comparators.

Description

one . 1 The invention relates to measuring instrumentation and can be used to control the parameters of electric machines, for example, when used in specialized equipment, diagnostic devices or universal automated control systems. A device for monitoring the parameters of electrical machines is known, which contains a monitoring and display unit, a current ripple sensor and a band-pass filter unit. A disadvantage of the known device is the low reliability of the control due to the fixed frequency. The settings of the individual band-pass filters that separate the various information components from the spectrum ripple current (voltage) of an electric machine. Closest to the present invention is a device for monitoring parameters comprising a field voltage generator connected by an output to an input of a peak detector connected by an output to a control input of a bandpass filter, a current ripple sensor, a block, a control, an amplifier, a maximum harmonic filter, a driver pulses and display unit 2. A disadvantage of the device is the limited range of auto-trimming of the bandpass filter unit. This is due to the fact that with changes in the rotational speed of the monitored machine over a considerable range (10% or more), the maximum harmonic of the ripple spectrum of the voltage (current) of the monitored machine, extracted with a band-pass filter, goes beyond the maximum harmonic filter bandwidth, and an increase in its bandwidth may result in the filter bandwidth of other components of the pulsation spectrum, which will cause the device to malfunction. In addition, for many electric machines, the amplitudes of the fundamental (toothed, collector, pole, etc.) harmonics of the spectrum are comparable, which also complicates the task of reliably extracting the amplitude of a certain harmonic when the rotational speed of the counter controlled machine varies over a wide range. All this ultimately 672 narrows the field of application of the known device .., The purpose of the invention is to expand the field of application of the device. The goal is achieved by the fact that a parameter control device containing a sawtooth generator connected by an output to the input of a peak detector connected by an output to a control input of a bandpass filter, a voltage pulsation sensor, a display unit, a reversing pulse counter, a controlled oscillator pulses, notch -. filter, sum.tor, first and second comparators, first, second and third keys, first, second and third integrators, first and second elements of the holder, first and second elements AND, element OR and pulse generator connected by an output to the summing input a reversible counter and a single trigger input connected by a zero input with a zero counter input of the reversing counter and an output of the first delay element, and direct and inverse outputs to the control inputs of the first and second, keys and the first inputs, respectively It is clear that the first and second And elements connected by the second inputs to the outputs of the first and second Comparators, respectively, and the outputs to the inputs of the Nm element connected to the input of the first delay element, with the subtracting input of the reversible pulse counter and through the second delay element with control inputs third keys connected to the outputs through the corresponding first integrators to the inputs of the display unit, and the inputs to the corresponding inputs of the bandpass filter unit and to the corresponding inputs of the adder, th output to the inputs of the first and second switches being connected, respectively, to the inputs the outputs of the second and third integrators outputs respectively associated with first and second inputs of the first and second comparators. . FIG. 1 shows a functional diagram of the device; in fig. 2 - timing diagrams explaining the principle of operation of the device; in fig. 3 - one of the possible options for implementing a tunable comb filter; in fig. 4 - the spectrum of pulsations and

frequency characteristics of a tunable comb filter in various modes of operation.

The device contains a clock generator of 1 pulses, a reversible counter 2, a trigger 3, a voltage pulsation sensor 4. A rejection filter 5, a controlled pulse generator 7, a sawtooth voltage generator 8. peak detector 9, unit 10 bands Yu. filters, adder 12, first 13, second 14 and third 6 keys, second 15 and third 16 and first 23 integrators, first 17 and second 18 comparator first element And 19 and second element And 20, element OR 21, first 11 and second 22 delay elements and display unit 24. The tunable filter 10 has a comb structure and contains bandpass filters 25, each of which is implemented on an operational amplifier 26 with frequency reference capacitors 27 and 28, a field transistor 29 and a control voltage divider consisting of a resistor 30 and a potentiometer 31. The letters A, B, ..., P denote the points on the functional diagram of FIG. 1, which correspond to the time diagrams on. 2. Diagram S in FIG. Figure 4 shows the spectrum of the signal at the output of the voltage ripple sensor (current), the X, Y, Z, and W positions in FIG. 4 denotes frequency characteristics of the bandpass filter unit 10 in periods of time indicated similarly in the time diagrams of FIG. 2. The principle of operation of the device is based on the gradual restructuring of the bandpass filter unit with simultaneous automatic control of the voltage at its outputs until the maximum totalizer signal of all components of the spectrum is obtained, after which the parameters of the informative components of the pulsation spectrum are indicated. The device works as follows 50 times. The pulses of the clock generator 1 are fed to the summing input of counter 2 and the counting input of trigger 3. At the forward output of trigger 3, odd-numbered clock pulses are generated, and inverse output is even (diagrams B and C in Fig. 2). Counter 2 counts the number of received clock pulses and accordingly tunes the controlled oscillator 7, which forms a sequence of pulses with a follow-up period constant within the tact, but decreases cycles with each subsequent clock (diagram D in Fig. 2). The pulses from the generator output 7 behind 45 start a sawtooth voltage generator 8, the amplitude of the sawtooth pulses (diagram E) is proportional to the pulse following period of the generator 7. Peak detector 9 generates a constant voltage proportional to the amplitude of the sawtooth pulses, which is controlled by the tunable 10 pole filter unit . The latter separates from the spectrum of pulsations coming at its input from sensor 4 through filter 5, those spectral components to which its band-pass filters are tuned. From the outputs of these filters, the voltage is applied to the adder 12, at the output of which a constant voltage is formed, which is proportional to the sum of the amplitudes of the spectral components separated by the bands of filters. This voltage is applied through the key 13, which is in the closed state by the voltage applied to it from the direct output of the trigger 3, to the integrator 15. The integrator remembers the maximum voltage applied to its input. This voltage is compared with a comparator 17 to the output of the HbD-j voltage of the second integrator. in this cycle, the first of them exceeds the second, then at the output of the comparator 17 there is a low level signal S, as a result of which the signal at the output of the element 19 also has a low level. At the output of the comparator 18, on the contrary, a high level signal appears, however, at the output of element I 20, the signal is low because its second input is affected by a low level voltage from the inverse output of trigger 3. Thus, at the output of the element OR 21 will be a low level signal. With the occurrence of subsequent clock pulses at the output of generator 1, the states of the outputs change

the triggers 3, the frequency of the pulses produced by the generator 7, decreases, which leads to the restructuring of the comb filters in the direction of increasing the frequency. Switched through the clock keys 13 and 14 alternately connect to the output of the adder 12 integrators 15 and 16, maintaining at their outputs a constant voltage equal to the maximum signal applied to their input. .

In all cycles up to the point of fine tuning the filters are inclusive, with each new cycle, higher levels of signals arrive at the integrators and, accordingly, the voltage at their outputs rises. The levels of the signals at the outputs of the Comparators and at the corresponding outputs of the trigger 3 do not coincide, which leads to the presence of a low level signal at the outputs of the I19 and 20 elements and the OR 21 element.

The maximum signal at the output of the adder 12 will be at the time of fine tuning (tick Z, diagram G). Obviously, in the next cycle, the filters will pass the peaks of the spectral components of the pulsations and the total signal at the output of the adder 12 will decrease (the beat W of the W diagram).

This will lead to the fact that at the outputs of the integrators the signal level does not change in comparison with the previous clock, it does not change at the corresponding inputs of the comparators, while at the other inputs the levels of the signals from the outputs of the trigger change from the previous clock on the opposite. This will lead to a coincidence of the signal levels at the inputs of AND elements 19 and 20, which will result in the appearance of a high level signal at one of their outputs (tick W, diagram H) and therefore the same. by the level of the signal at the output of the element OR 21.

The latter, arriving at the inverting input of the reversible counter 2, reduces the unit of the code recorded in it and rebuilds the filter unit 10 accordingly, thus repeating the circuit operation in the previous cycle, when the total signal at the output of the adder 12 had the maximum value and corresponded to the fine tuning block 10 bandpass filters on the harmonics of the rotational speed of the electric machine.

At the same time the signal from the output of the element OR 21 is fed to the inputs of the elements 11 and 22 of the delay. Their chip time is equal to the minimum required time of the above-described process of reverse switching of counter 2 and the corresponding reorganization of filter 10. The signal from the output of delay element 11 is the keys 6 that pass the voltages of the components selected by the filters of block 10 to the input of the integrators 23, which memorize them and transmit for display in the block 24 of the display.

During the tuning frequency search periods, the integrators 23 and the display unit 24 retain the last of the determined values until the next time the extremum is detected, after which the information in the integrators 23 and the display unit is updated. The discreteness of the process can be reduced by increasing the frequency of the clock pulses generated by the generator 1.

As a sensor of 4 voltage pulses, in the proposed device, a shunt can be used in the circuit of an electric machine. The 5-filter for DC machines uses a low-pass filter with a cut-off frequency equal to the maximum tuning frequency of the comb filter 10, and for an AC-powered machine, a notch filter that suppresses the pulsation spectrum component with the grid frequency.

From the experimental research of the scientific research institute it follows that the optimal number K of parallel-connected tunable filters for aircraft electrical machines ranges from 15 to 40.

Thus, the proposed control device provides adjustment of filters to the K spectral components of the current (starting from the first) which are multiples of the rotation frequency and thus allows unambiguously controlling their amplitude (and, if necessary, frequency) for any changes in the rotation speed of the electric machine. At the same time, failures and misses in estimating the parameters of the constituted components of the pulsation spectrum, which are characteristic of the known device and are caused by 7.1 falling into the band pass of the maximum harmonic of the off-design component and caused by improper adjustment of filters, are excluded. The proposed device is universal, since it is applicable to dp of any electric machines (collector machines of direct and alternating current with different excitation, asynchronous, etc.) and in any modes of their operation (start, braking, etc. 7, which causes a new technical effect - expansion of the field of application. 7 In turn, the expansion of the field of application makes it possible to increase the efficiency of use of control means by expanding the range of controlled Products, as well as applying control in matic operation. For example, the use of the device for controlling the parameters aviatsionnk electric machines provides a reduction of costs of implementation diagnosing about 30%,

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Claims (1)

PARAMETER CONTROL DEVICE, comprising a sawtooth voltage generator, connected by an output to a peak detector input, connected by an output to a control input of a bandpass filter unit, a voltage ripple sensor, an indication unit, characterized in that, in order to expand the scope of the device, a reversible counter is introduced into it pulses, controlled pulse generator, notch filter, adder, first and second comparators, first, second and third keys, first, second and third integrators, first and second elem nt delays, the first and second And elements, the OR element, and the pulse generator, connected by the output to the summing input of the reverse counter and to the single input of the trigger, connected by a zero input to the input of zeroing the reverse counter and with the output of the first delay element, and by direct and inverse outputs to control inputs of the first and second keys, respectively, and to the first inputs of the first and second AND elements, respectively, connected in the second inputs to the outputs of the first and second comparators, respectively, and the outputs to the moves of the OR element associated with the output with the input of the first delay element, with the subtracting input of the reverse pulse counter and through the second delay element with the control inputs of the third keys connected by the outputs through the corresponding first integrators to the inputs of the display unit, and the inputs * to the corresponding inputs of the bandpass filter unit and to the corresponding inputs of the adder connected by the output to the inputs of the first and second keys connected by the outputs to the inputs of the second and third integrators, respectively, connected output ami with <35 oe 05 m responsibly with the first and second inputs of the first and second comparators. >