SU1485132A1 - Device for monitoring rotation frequency of electrical machine - Google Patents

Description

The invention relates to measuring equipment, in particular to the measurement of the speed of rotation of electric machines, and can be used in control systems of the mode of electrical units. The aim of the invention is to increase the reliability of the control. The signal from the pulsation sensor 1 through the notch filter 2 is fed to the input of the synchronous filter 3, and the synchronization filter 3 is tuned in the first device operation cycle over the entire controlled frequency range while the maximum integrator 6 is remembered by the first integrator. In the second cycle the synchronous filter is tuned 3 until the output value of the signal is equal to the maximum value memorized in the previous cycle, then the value of the tuning frequency is synchronous of the filter 3 is displayed on the display 19 and the measurement cycle is repeated.

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FIG. one

3

four

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The invention relates to the measurement of the speed of rotation of electric machines and can be used in various systems for controlling the frequency of electric aggregates, for example, in diagnostic and auto-monitoring systems,

The purpose of the invention is to increase the reliability of control, Yu

FIG. 1 shows a functional diagram of the device; figure 2 timing diagrams explaining the principle of the device; in FIG. 3, the spectrum of the pulsations of the electric machine and the frequency characteristics of the synchronous filter in various modes of operation.

The device contains series-connected pulsation sensor 1, 20 notch filter 2 and synchronous filter 3, first 4 and second 5 keys, first 6 and second 7 integrators, connected in series comparator 8, delay element 9 and one 25 vibrator 10, clock generator 11, trigger 12, series-connected voltage generator 13, voltage converter 14 voltage ~ code, second element 15, second 30 register 16, first element 17, first register 18 and indicator 19, voltage-frequency converter 20,

The device works as follows 35 times.

32

The operation of the synchronous filter 3 is shown in FIG. When the reference frequency of the synchronous filter 3 is tuned, a voltage proportional to the sum of the amplitudes of the spectral components extracted from the signal from sensor 1 (FIG. 2, E) is formed at its output. Therefore, the integrator, 6 connected to the filter output, remembers the global maximum value that does not depend on numbers and magnitudes of local maxima. The second clock pulse of the generator 11 changes the state of the trigger 1.2 and restarts the generator 1.3. When this occurs, the restructuring of the synchronous filter 3 is similar to that described in the first cycle, but now its output voltage goes to the integrator 7,

At the moment ί _ί , the voltages at the inputs of the comparator 8 are achieved and a voltage drop forms at its output, which closes the AND 15 element, preventing the register 16 from changing state; in which the code of the rotational speed of the electric machine is written, which is rewritten into register 18 and displayed by the indicator 19. The delay element 9 and the one-shot 10 set all the elements of the device to the initial state, after which the described process repeats,.

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Claims (3)

Claim In the initial state at the output of the comparator 8 there is a signal of logical zero, which closes the element And 17 and opens the element And 15, Trigger 12 and the registers 16 and 18 are set to the zero state. The pulses of the clock generator 11 (Fig, 2, A) are fed to the input of the trigger 12, to the start of the generator 13 of the stepped voltage and to the zero input of the register 16, the Generator 13 generates the pulses of the stepped voltage (figure 2, D), which are converted into a sequence pulses with a discretely varying repetition frequency (Fig, 2, D), which is fed to the control input of the synchronous filter 3. The code from the output of the converter 14, proportional to the frequency of the pulses of the converter 20, is written through the open element 15 to the register 16. An electric machine speed control device containing 40 series-connected current ripple sensor and notch filter, series-connected clock generator and trigger, direct and inverse outputs of which are connected to the control inputs of the first and second keys, respectively, series-connected comparator and delay element, the first integrator connected between the output of the first 5θ key and the first input of the comparator, the second integrator connected between the output of the second key and the second input of the comparator, the first element AND, the first register and the indicator, the first input of the first element AND are connected to the output of the comparator, characterized in that, in order to increase the reliability of the control, enter 5 1485132 6 one-shot, connected between the output of the delay element and the control inputs of the integrator and comparator, a synchronous filter whose input is connected to the output of the notch filter, and the output to the inputs of the first and second keys connected in series to a step voltage generator, voltage converter - code, second element And second the second input of the first element And the voltage-frequency converter connected between the output of the step voltage generator and the control input of the synchronous filter, the inverse input of the second element And connected to the output of the comparator and the control input of the generator speed 1θ of the first voltage, the start input of which is connected to the output of the clock generator 1485132