SU1035770A1 - Device for controlling electric power unit frequency - Google Patents

Abstract

A DEVICE FOR REGULATING THE FREQUENCY OF AN ENERGY UNIT containing a square pulse former, the direct and inverse outputs of which are connected to the first inputs of the first and second elements, respectively, the pulse counter of the direct counting, the first pulse generator having a reference frequency connected by its output to the counting input of the direct counting counter, RS trigger, the direct and inverse outputs of which are connected respectively to the second inputs of the first and second And elements, the third inputs of which are connected and a one-shot, the input of which is connected to the inverse output of the square pulse generator, and the output to the input of the initial setting of the direct counting pulse counter and the R input of the RS flip-flop, in order to increase speed control and improve the quality of transients in the frequency control, it is equipped with a second one-shot, third, fourth, fifth and sixth logical elements And, the second RSrigger, count counter pulses, the third impulse generator, reversible pulse counter. Two logic elements KW OR, while the input of the second one-shot is connected to the forward output of the square pulse generator, and its output is connected to the synchronization input of the counting counter of the counting pulses and the R input of the second RS flip-flop, one input of the third element And the subglue to the output of the first generator (L pulses, OTHER - to the inverse output of the rectangular imp: pulse generator, the output of the third element AND is connected to the counting input of the counter of the counting pulses, the output of which is connected to the S-input meters of the second RS flip-flop, the inputs of the fourth from the logic element I are connected to the outputs of the bits of the pulse counter of the direct counting and to the inputs of the parallel synchronous recording of the countdown timer, the output of the fourth logic element I is connected to the input of the first RS-trigger, the first inputs of the Fifth and the sixth logic elements AND are connected respectively to the inverse and direct outputs of the square pulse generator, the second - respectively to the forward and inverse outputs of the second RS-flip-flop, the third are connected to the output the third pulse generator, the outputs of the first and fifth logical elements AND through one scheme OR

Description

connected to the forward count input of the reverse pulse counter; the outputs of the second and sixth logic elements AND through another circuit; OR 1035770 connected to the reverse count input of the rotational counter, the overflow outputs of which are connected to the corresponding output pulse expanders.

The invention relates to the automation of operating modes of energy facilities and can be used to control the frequency of the voltage of electrical units and mobile power plants.

There are known devices for controlling the frequency of the power unit, which regulate the flow of fuel to the engine in accordance with the deviation of the generated frequency from the nominal frequency, which is measured using accurate digital methods by counting the number of reference pulses from the reference pulse generator 8 to the counter of pulses. 1 and 2}.

However, control of the actuators in these devices is performed by the voltage level, for which an analog time converter is used, which has a high duty cycle, into a proportional voltage, which causes a lack of accuracy and speed of the devices.

Closest to the invention is a device for controlling the frequency of a power unit, comprising a driver of direct pulse pulses, the direct and inverse outputs of which are connected to the first inputs of the first and second elements, respectively, the first pulse generator having a reference frequency connected to the counter input of the counter direct counting, RS-trigger, direct and inverse outputs of which are connected respectively to the second inputs of the first and second And elements, the third inputs of which are connected to the output the second pulse generator, and a one-shot, the input of which is connected to the inverse output of the rectangular pulse former, and the output from

the input of the initial installation of the pulse counter of the direct counting and the R-input of the RS flip-flop. The device generates pulses of constant duration for

corresponding to the sign of the frequency deviation output with a duty ratio proportional to the deviation of the regulated frequency from the nominal GZ. However, this device regulates only the frequency deviation from the nominal and does not take into account the rate of its change, which does not allow for a high rate of testing short-term perturbing frequency deviations and high quality transients, for example during abrupt load sheds.

The purpose of the invention is to increase the speed of regulation and improve the quality of transients during frequency control.

The goal is achieved by the fact that a device for controlling the frequency of a power unit, comprising a square pulse shaper, the direct and inverse outputs of which are connected to the first inputs of the first and second elements, respectively, the forward count pulse generator, the first pulse generator having a reference frequency, connected by its output to the counting input of the direct counting counter, RS trigger, direct and inverse outputs

which are connected respectively to the second inputs of the first and second elements I, the third inputs of which are connected to the output of the second pulse generator, and a one-shot whose input is connected to the inverse output of the square pulse former, and the output to the input of the initial installation of the pulse counter of the direct counting pulse and R-input of the RS-flip-flop, equipped with the second one-shot, third, fourth, fifth and sixth 31 logic gates And, the second RS-flip-flop, counter of counting pulses, the third pulse generator, reverse A pulse counter, two OR logic elements, while the second one-vibrator input is connected to the forward output of a square pulse shaper and its output is connected to the sync input of the counting pulse counter and the R-input of the second RS flip-flop one input of the third element And the to the output of the first pulse generator, the other to the inverse output of the form1 / "rectangular pulse rotator, the output of the third AND element is connected to the counting, the input of the counter of the counting pulses, the overflow output of which is single with the 5-input of the second -RS-TpMrrepa, inputs of the fourth logical gate I are connected to the outputs of the bits of the pulse counter of the direct counting and with the inputs of parallel synchronous recording of the counter of the counting counter, the output of the fourth logic element I is connected to the S input of the first RS -trigger, the first inputs of the fifth and sixth logical elements And are connected respectively to the inverse and direct outputs of the square pulse generator, the second - respectively to the direct and inverse outputs of the second RS-flip-flop, the third are connected to the output the third pulse generator, the outputs of the first and fifth logic elements AND through one circuit OR connected to the forward count input of the reversible counter of pulses, the output of the second and sixth logic elements AND through another circuit connected to the reverse count input of the reverse counter, the overflow outputs of which are connected to the corresponding output pulse expander. The outputs of the pulse expanders are connected to an additional device that reduces or increases the fuel supply. Figure 1 shows the structural diagram of the proposed device; 2 shows timing diagrams for the reasons for its operation. The device contains a rectangular pulse shaper 1, npeq6praising sinusoidal voltage Up, generated by energy object 0 into symmetric rectangular pulses (an additional counting trigger - a divider by two) can be used, the first generator 2 pulses having a reference frequency connected to the counting input counter 3 direct counting, the input of the initial installation (NC) of which is connected to the output of a one-shot, forming a short setting pulse at the beginning of a rectangular pulse from the direct output shaper 1 (when using the inverse output of shaper 1 on the falling edge), first trigger 5, second pulse generator 6, first and second logic elements AND 7 and 8, output expanders 9 and W pulses, and second one-shot 11, forming a short Setting pulse at the end of the rectangular impulse from the forward output of the imaging unit 1 (on the leading edge when using the inverse output), the third, fourth, fifth and sixth logic elements AND 12-15, the second RS-flip-flop 1b, the counter 17 of the counting pulses, the third gene pulsator 18, reversible pulse counter 19, two logical elements OR 20 and 21, the counter 17 counting has a C-input synchronization input and inputs of parallel synchronous recording associated with the outputs of bits (QJ ,, Q ,. .., Q) of the counter 3, and the reversible pulse counter 19 has inputs of forward + T and reverse -T counts and overflow outputs + P by switching the state of the counter from maximum to zero when adding and -p by switching the state of counter from zero to maximum when subtracting. The device works as follows. For a controlled frequency sine wave, shaper 1 generates symmetric rectangular pulses with fronts coinciding with voltage sine wave transitions through zero (Fig. 2) and period T. According to the output frequency signal of shaper 1, the single vibrator L forms a short pulse, producing a zero initial setting of counter 3 and RS trigger 5. In the interval between two pulses of a single vibrator, counter 3 counts the number of reference pulses arriving at its counting input + T from reference generator 2, starting with the initial state, write th counter in the entry for 3 OH (initial setting) monostable pulse t. When counting by the number of reference pulses of a given time corresponding to the half-period of the nominal frequency, the estimator 3 assumes a certain state in which the output of the circuit 13, its inputs connected to the outputs of the counter 3 corresponding to this state, causes a flip-flop 5 condition. As a result, at the output of the trigger 5, an interval t Y of the elements And 7 and 8 is formed over half-periods and t compares the reference periods generated by the control object and the difference between these durations near the middle of the period in the interval, passes impulses from the generator 18 pulses through the OR circuit 20 and 21 to the corresponding counting inputs + T or a reversing counter 19. Counter 19 accumulates, taking into account the sign, the counting pulses from the Accounting Inputs -I and T and at the instant of overflow 4- or - generates an impulse to the corresponding yuschem outlet 4-P or -P. The pulse is expanded in expanders 9 or 10 to a value sufficient to control the actuator, for example, an electric motor, which adjusts the frequency in the required direction. In the event that the frequency of the generated voltage is less than the nominal value, the counting pulses come from the output of element 7 to the input +1 of the counter 19 and at its output -fP the pulses are generated through the expander 9 to the executive motor, increasing the frequency of the generator. If the frequency of the generated voltage is greater than the nominal value, the counting pulses come from the output of the element 8 to the input -T of the counter 19, and at its output -P the pulses are generated through the expander 10 to the actuator electric motor, reducing the frequency of the generated voltage. Thus, proportional control of the actuation device for regulating the fuel hearth is carried out depending on the magnitude and sign of the frequency deviation from the nominal value. In order to increase the speed of regulation and the quality of transients during frequency regulation, especially in case of sudden frequency fluctuations, for example, in case of drops - load ramps, the dependence of the controlled effect on the rate of change of frequency (first derivative) is necessary. To do this, at the end of the first half (t, tр, ..4), the one-shot 11 generates a short pulse that sets the control trigger 16 to the zero state and rewrites the contents of the counter 3 to the counter 17 that corresponds to the duration of the first half period of the generated frequency. The pulses arriving thereafter at the input of the counter 1 decrease its state, and at the moment of transition through the zero state, an output is generated at the output of the P-counter 17, which transfers the trigger 16 to a single state. As a result, the counter 17 in the second half period counts the time interval t, tf ,,., Equal to the duration of the first half period. This interval is formed at the outputs of flip-flop 16 and compared with the duration of the second half-period by elements AND And 15, through which the counting pulses from the generator 18 are passed through the corresponding inputs + T or -T of the cumulative counter 19 at the difference interval of these values. Thus, the difference between the first and second half of the period T, i.e. the magnitude of the frequency change in the interval is half the period T. In accordance with the sign of that difference in an amount proportional to its magnitude and frequency of the 18-pulse generator, the counting pulses arrive 6 counter 19, accumulating it with the previously received quantity and sign (t. e. channel h-t or -t) pulses. Therefore, the accumulated amount in the counter 19 characterizes both the frequency deviation from the nominal and the rate of change of the frequency. In case of an increase in the frequency (reduction of the period), the counting pulses come from the output of the element AND 15 through the element OR 21 to the input -T of the accumulation counter 19, reducing its content and thus correcting the adjustable frequency in the direction of decreasing. In the case of a drop in frequency (period increase), the counting pulses (Fig. Come from the output of the element AND T through the element OR 20 to the input + T of the compact counter 19, increasing its content and thus adjusting the control in the direction of increasing the frequency. In so doing, the counting pulses from elements 1 and 15 can only come near the beginning of period T, & and by which the arrival of counting pulses at the inputs of counter 19 from elements 14, 15 and 7, 8 separately in time, the ratio of dependence on deviation from nominal and derivative frequency the ratio of the frequencies of the generators 6 and 18. In some cases, the generators 6 and 18 can be replaced by one common generator or generator with a divider or generator 2, which, if necessary, can be supplemented by a divider.The steepness of the total final control characteristic is determined, besides the frequencies of the generators with a capacity of 708 counter 18, and through channels ff or if also the duration of the pulses generated by expanders 9 and 10. Pulse generators 6 and 18 do not require high accuracy and stability of the frequency they generate, since these are rejected their frequencies only slightly on the steepness skazyvayuts a regulatory characteristics; Thus, the inventive device allows, with intrinsic high-precision digital devices, to generate control pulses with a constant for sufficient to affect the actuator with a tracking frequency exceeding the frequency of the generated voltage and proportional to both the frequency deviation from the nominal value and the rate of change of frequency which provides an increase in the speed of testing the disturbing frequency deviations from the nominal frequency and an improvement in the quality of transients. The device can be made in commercially available integrated circuits, which are functional elements of the given structural diagram.

Fie.2

Claims (1)

/ DEVICE FOR REGULATING THE FREQUENCY OF THE POWER UNIT, containing a rectangular pulse shaper, the direct and inverse outputs of which are connected to the first inputs of the first and second elements I, respectively, a direct count pulse counter, the first pulse generator having a reference frequency, connected by its output to the counting the input of the direct counter, RS-trigger, the direct and inverse outputs of which are connected respectively to the second inputs of the first and second elements And, the third inputs of which are connected to the output of the second pulse generator, and a one-shot, the input of which is connected to the inverse output of the square-wave pulse generator, and the output is connected to the input of the initial installation of the direct count pulse counter and the R-input of the RS-trigger, characterized in that, in order to increase the speed of regulation and improve the quality of transients during frequency control, it is equipped with a second one-shot, third, fourth, fifth and sixth logical elements AND, a second RS three-gerry / counter counter pulses, the third generator m pulses, with a reversible pulse counter, Two logical elements OR, while the input of the second one-shot is connected to the direct output of the rectangular pulse shaper, and its output is connected to the recording synchronization input of the countdown pulse counter and to the R-input of the second RS-trigger, one input of the third the And element is connected to the output of the first pulse generator, the other to the inverse output of the rectangular pulse shaper, the output of the third And is connected to the counting input of the countdown pulse counter, the output is overflow which is connected to the S-input of the second RS-flip-flop, the inputs of the fourth logical element And are connected to the outputs of the bits of the counter of pulses of the direct counting and to the inputs of the parallel synchronous recording of the countdown counter, the output of the fourth logical element And is connected to the S-input of the first RS-flip-flop, the first inputs of the fifth and sixth logical elements And are connected respectively to the inverse and direct outputs of the square-wave pulse generator, the second to the direct and inverse outputs of the second RS-trigger, respectively, the third soy Dinen with the output of the third pulse generator, the outputs of the first and fifth logic elements AND through one circuit OR ... SUn .. 1035770 are connected to the input of the direct counting of the reverse pulse counter, the outputs of the second and sixth logic elements AND through another circuit OR I are connected to the input of the counting down of the counter meter, the overflow outputs of which are connected to the corresponding output pulse expanders.