SU1092690A1 - Automatic control of generated voltage frequency - Google Patents

Abstract

AUTOMATIC FREQUENCY REGULATOR OF GENERATED VOLTAGE (ENIA, containing a rectal impulse generator corresponding to a controlled frequency, a reference frequency generator, the first logic circuit is connected to the output, and the second input of which is connected to an extension of a rectangular impulse output circuit, a auxiliary circuit is connected to an auxiliary circuit, and the auxiliary circuit is connected to the output of the rectangular impulse generator; pulse counter counting, the second logic And, the output logic And, characterized by the fact that, in order to increase accuracy and speed, it is equipped with a circuit analysis and the counter states, a reference frequency divider and a single vibrator, and the counter is equipped with an additional countdown input connected to the output of the second logic circuit AND, to the second input of which a reference frequency divider connected to the reference frequency pulse generator is connected to the first input of the second logic circuit And a square pulse shaper is connected, the output of which is connected through the one-shot to the input of the initial device (the pulse counter, the outputs of which are connected to the inputs of the analysis circuit The stand of the counter, the output of which is connected to one of the inputs of the output logic circuit And, the other input of which is connected to the output of the square pulse former, and the output of the output logic circuit And is the output of the device. X) ND; o o o

Description

The invention relates to the automation of operating modes of alternating current electrical units and can be used to stabilize the frequency of mobile electrical units, in particular with a generator driven by carburetor internal combustion engines. Automatic frequency controllers are known that react to frequency deviation from nominal, but lack sensitivity and speed due to the use of analog principles. measuring the frequency deviation from the setpoint 1} and 2, the closest to the technical essence of the invention is a frequency controller, in which the determination of the frequency deviation from the nominal value is made using precise digital principles. The known frequency regulator contains a shaper of rectangular pulses corresponding to the adjustable frequency, a generator of impulses of a reference frequency, the output of which is connected to the first logic circuit AND, the second input of which is connected to the output of the former of rectangular impulses, and the output pulse counter counts are the second logical AND circuit, the output logic circuit is AND 3. However, this frequency regulator cannot provide high sensitivity to frequency deviation, just to maintain its JHocTb and speed, since the duty cycle of pulses coming from the coincidence circuits to the analog converter at small frequency deviations is very high: when the frequency deviates from nominal The 1% duty cycle of pulses is 100, with a deviation of 2%, the duty cycle of pulses is 50, etc. An actuator, for example, an electric magnet of the frequency regulator, cannot provide a high-quality regulated with such a high pulse duty cycle. Therefore, it is necessary to introduce into the frequency regulator another analog converter, which reduces the accuracy. And the speed of the system is adjustable. The purpose of the invention is to improve the accuracy and speed of the automatic frequency controller. The goal is achieved by the fact that an automatic frequency regulator of the generated voltage containing a square pulse shaper corresponding to a controlled frequency, a pulse generator of a reference frequency, the output of which is connected to the first logic circuit AND, the second input is connected to the output of the grain distributor rectangular pulses, and the output is connected to the input of the direct count of the pulse counter, the second logic circuit AND, the output logic circuit AND, is equipped with a circuit for analyzing the state of the counter, a divider the frequency and the one-shot, and the counter is equipped with an additional counting input connected to the output of the second logic circuit AND, to the second input of which a reference frequency divider connected to the reference frequency pulse generator is connected to the first input of the second logic circuit And the square pulse shaper is connected, the output of which is connected through a single-nibrator to the input of the initial installation of a pulse counter, the outputs of which are connected to the inputs of the circuit for analyzing the state of the counter, the output of which is connected It is connected to one of the inputs of the output logic And, the other input of which is connected to the output of the square pulse former, and the output of the output logic And is the output of the device. FIG. 1 shows the structural scheme of the automatic frequency regulator; FIG. 2 is a time diagram illustrating the principle of operation of the device j. . . . The device contains a square pulse shaper 1 that converts a sinusoidal voltage with a frequency generated by the control object into rectangular pulses (FIG. 2), a reference frequency generator 2, connected through divider 3 and logic circuits 4 and 5 to direct inputs counting and counting the pulse counter 6, and logic circuit 7 for analyzing the state of counter b, as well as the one-shot 8, which is the initial setup of the counter 6, connected to the input of the initial setup (LC) of the counter and the output logic The circuit is AND 9. The output of the device is the output of the logic circuit AND 9. The electrical unit generates a voltage with frequency f that is applied to the input of the rectangular: pulse 1. By passing a sinusoid voltage through a zero value, the former 1 generates square pulses with a period T 1 / f, arriving at the inputs of the And 4 and 5 circuits, controlling their state. During one half-wave of the input signal corresponding to the first half of the period T (Fig. 2), circuit 4 transmits counting pulses from generator 2 to the input of the reversible counter 6. At this moment, circuit AND is open with a control signal from driver 1, and circuit 5

is closed. For this, for example, the input of the circuit And 5 inverts the control signal (a similar state of the logic circuit And can be obtained having two outputs of the driver 1, the pulses of which are inverted relative to each other). In the second half of the period T, on the contrary, the signal from the imager 1 opens an AND 5 circuit, and the AND 4 closes, i.e. circuit 5 transmits pulses from divider 3 to the input of reversible counter 6. Simultaneously at the beginning of period T (on the leading edge of a rectangular control pulse from shaper 1), one-shot 8 generates a short pulse that arrives at the input of HL counter 6 and carries out its installation in initial state. For the same purpose (as the setup circuit of the meter 6), other devices such as a current multivibrator, a short pulse shaper, and the like can be used.

At the input of the direct counting in the first half of the period T, the generator of the reference frequency 2 comes from pulses with a period T through an open logical element 4, and by the beginning of the second half of the period T counter 6 counts from the initial state {t () the number of pulses equal to T / 2Ts. In the first half-period T, the logical signal at the output of the device does not depend on the states of counter 6, which determine the value of the output signal of analysis circuit 7, since the logical circuit 9 from its inverting input is closed by a logical signal (single) from the former 1.

In the second half of the period T, the AND 4 logical scheme is closed, the AND 5 scheme is open and the AND 9 output scheme is also open. The counting pulses from oscillator 2 in this case, having passed through frequency divider 3, are expanded by K times (K is equal to the division factor of divider 3) and through logic AND 5 are fed to countdown input -1 of counter 6 and subtracted from those counted by input + 1 number T / 2Tj ,, i.e. given the initial state of the state of the counter mg4T / 2To,

A logic circuit for analyzing the states of counter 7, which in its simplest form represents a coincidence circuit with an inverting output, switched on by a certain number (from b to n) of the last outputs (Q .. ..Q,) of counter 6, analyzes two regions of the counter state it, where m is the current state of the counter. The boundary of the regions l is equal to the number 2 + ... 2 (Fig. 1), where b and n are integers, indicating the numbers of the counter outputs in the order of increasing their weights,

The number of the last outputs of the striker 6 connected to the coincidence circuit (p-b) depends on the value

1 - fixed be1 + t .1

Where

the year and the initial state

the counter and is determined from the ratio 2 + 2 - + ... +

2 1 + m.

For example, at.

() AND

  + ... +

relations are defined by n, therefore. It follows from this that the Yu and 11th outputs of a twelve-bit counter with numbering from 0 to 11 bits must be connected to the coincidence circuit, and a two-input coincidence circuit can be used as a circuit for analyzing the state of the counter. When at the output of circuit 7 one value of the logical signal (zero level), and for m - another (single level).

At the output of the device, the logical signal from the circuit 7 passes through the reference to AND 9, which passes the signal from the circuit 7 only in the second half of the period T.

The parameters of the frequency regulator (reference frequency generator 2, divider division factor 3, counter B capacity, t value) are chosen such that at the nominal voltage frequency input to shaper 1, the time is in the middle of the second half of the period T. the value of l, the parameters of the elements of the controller in this case are related by the ratio 1

L - TC

+ t, where K is the coefficient 2To 4KTo division of frequency divider 3. Then, if the controlled frequency deviates to its decreasing direction (T and 2 / Tto increase), the counter states m 1 may be (depending on the deviation value) from the middle of the second half period T to its end, and the pulse duration at the output of the circuit, respectively, from T T / 4 to.

When the adjustable frequency deviates in the direction of its increase (the duration T and the number T / 2Ta decrease) the states of the counter m 1 can be from the beginning of the second half period to its middle, and the pulse duration at the output 7, respectively, from to 1/4.

When the maximum impact is made on the energy supply mechanism to increase the frequency (for example, by compressing the spring), and when - the maximum effect is to reduce the frequency (for example, by an electromagnet that stretches the spring).

When the frequency deviations are close to zero, impulses with a duration close to tbT / 4 are received from the output of circuit 7 one pas per period to the fuel supply mechanism (the discreteness is equal to K T, insignificant, since T Т).

Changing the division ratio of frequency divider 3, you can select any frequency deviation range in which t varies from 0 to T / 2, for example, in the zone, the linearity is maintained in the selected range, (4T) dependencies, Out. the selected range, the pulse duration is equal to the duration

corresponding to the border of the range, i.e. f-q or.

Thus, the proposed automatic frequency regulator allows to increase the speed of the regulating action (by eliminating the delay of the analog converter) to the magnitude of one period of the generated voltage, as well as the accuracy of maintaining the nominal frequency due to the linear dependence T (dT) in a given zone and the slope of this the dependences are the same for both positive and negative signs of frequency deviation from nominal, which allows for high quality transients.

Ww. t

Claims (1)

AUTOMATIC REGULATOR OF THE GENERATED VOLTAGE FREQUENCY, comprising a rectangular pulse shaper corresponding to an adjustable frequency, a pulse frequency generator of a reference frequency, to the output of which a first logic circuit I is connected, the second input of which is connected to the output of the square pulse shaper, and the output is connected to the input of the direct count of the pulse counter, the second the logical circuit AND, the output logical circuit AND, characterized in that, in order to improve accuracy and speed, it is equipped with an analysis circuit consisting of counter, a reference frequency divider and a single vibrator, and the counter is equipped with an additional countdown input connected to the output of the second logic circuit AND, to the second input of which a reference frequency divider connected to the pulse generator of the reference frequency is connected, a shaper is connected to the first input of the second logic circuit AND rectangular pulses, the output of which through a single-shot is connected to the input of the initial installation of the pulse counter, the outputs of which are connected to the inputs of the circuit for analyzing the states of the counter, in stroke which is connected to one input of the output AND circuit, the other input of which is connected to the output of the rectangular pulse, and the output of the AND circuit output is the output device. Fie. 1 SU ,,,. 1092690>