SU1260873A1 - Device for determining amplitude-frequency characteristics of electric power plants - Google Patents

Abstract

This invention relates to a measurement technique. It can be used to determine the amplitude-frequency characteristics (AFC) of power facilities. The aim of the invention is to improve the accuracy of determining the frequency response of electric power facilities under the conditions of interference. To achieve this goal, in device 1-a-l I Lz: L..bf is a solution containing a tunable frequency generator 1, quadrupole 2 under investigation, switch 3, analog-to-digital converter 4, 7 code divider, result and frequency indicator 8, block 9 controls, the first register 10, the first 12 and the second 13 terminals for connecting the tested quadrupole, the pulse generator 16 and the counter 17, the first | 4 5 and the second 6 adders and the second register I1 are entered. The generator 1 is made in the form of a controlled generator 14, the unit 15 setting the law of frequency control. Blocks 14 and 15 are made according to the interpolating functional converter circuit. The discrete values of the frequency response and the digital code stored in the indicator 8 can be used for visual observation of the frequency response using two digital analogue converters and a two-coordinate plotter or used for digital computer calculations for control or identification tasks. 1 hp f-ly, 5 ill. kN С S (П с 1С а о 00 00

Description

This invention relates to measurement techniques and. can be used to determine the amplitude-frequency characteristics (AFC) of electric power facilities.

The purpose of the invention is to increase the accuracy of determining the amplitude-frequency characteristic of power facilities, under the conditions of interference.

 FIG. 1 shows a block diagram of the proposed device; 2 to 4 are timing diagrams explaining the operation of the device; in fig. 5 is a timing diagram of the operation of the control unit of the device.

The device (Fig. 1) contains a tunable frequency generator 1 connected in series, a quadrupole 2 under study, a switch 3, a v-analog-to-digital converter (ADC) .4, the first 5 and the second 6 adders, a digital divider of 7 codes, a result indicator 8 and frequencies , control unit 9, first 10 and second 11 registers, first 12 and second 13 terminals for connecting a quadrupole under study.

The tunable frequency generator 1 is implemented in the form of a controlled oscillator 14, the input of which is connected 1 with another output of the task unit 15: a frequency control ZAKON, the second output of which is connected to one input of the control unit 9, a pulse generator 16 and a counter 17.

Managed; The generator 1 and the unit 15 for setting the law of frequency control are made according to the interpolating functional converter circuit.

The controlled oscillator 14 generates the output signal and gK, shown in FIG. 4S. The law of change in the frequency of the signal Irc is shown in FIG. 4 a. The generator 14 generates pulse signals with a frequency F; .2 at output S and frequency F; .2 output c, where F) is the frequency of the signal of a given form in each period.

Block 15 at the output d outputs signals with frequency G; . 2

The control block 9 represents a counter with logic elements at the input and a decoder at the output. Time diagrams of the operation of block 9 are shown in FIG. 5. The input of block 9 receives signals from the output of the generato. Pa, 14, and during the pause P

(Fig.48 - from the output of block 15, pulses Lb, - Abp. Output signal (Jgbiic of the quadrupole is shown in Fig. 4b. It contains a constant component

and post.

Electronic switch 3 is designed to connect the input and output signals to the input of the A / D converter. The control signal of the switch comes from the output of control block 9 (Fig. 5e).

Analog-to-digital converter 4 converts the instantaneous values of the input or output signals to it into digital form. The conversion command comes from the output of control block 9 (Fig. 59).

The adder 5 is designed for semi-

the mean value of constant

25

component of the Osgra f,

pause, the sum of modules of instant values

The input signal ZI / A.,; /

J

4J

0

five

for the first period of oscillation of the input signal and to obtain the moduli of the instantaneous values of the signal of the quadrupole 2 by subtracting from. instantaneous output sig. A jjj (Fig. 2a) is the average value of the constant component U „0. The digital code from the output of the A1DP is fed to the input of the adder 5. The control signal of the adder comes from the output of the control unit 9 (fig.d).

Register 10 stores the average value of the constant component (J "p (,. This value is recorded by register 10 from the second output of the adder 5 at the end of the pause, following a command from the output of control block 9 (Fig. 5). Value 1 ,, OSG from the output of register 10 in the additional code goes to the second input of the adder 5.

Register 11 stores the value B, which is written to the register.

11 from the first input of the adder 5 at the end of the first period by a command from the output of the control-block 9 (figure 5).

The adder 6 is designed for half the amount of samples of the instantaneous values of the response signal / for the period of the input signal. Values come from the first exit.

control of sum-output unit 9

digitally amount

/ Aj ;;

/,

on

adder 5. The signal from the mater comes from the control (Fig. 5g.

The divider 7 carried out

R

D) -,.

The value B coming from the output of the adder 6, coming from the output of the register 11. The command to divide comes at the end of each period to the input from the output of the control unit (Fig. 5 and.

The generator 16 is designed to generate stable frequency pulses.

The counter 17 is designed to determine the frequency in each period of the disturbance signal. The resolving input of the counter 17 receives a signal from the output S of the generator 14, equal in duration to the current period of the disturbing signal, and the counter input of the counter 17 receives pulses of a stable frequency from the output of the generator 16. At the end of each period, the disturbing signal at the output of the counter 17 is formed N code; proportional to the frequency of this period. The counter is set to O at the end of each period by a command from the output of the control unit 9 (Fig. 5), which is fed to the control input of the counter 1 7.

Result and frequency indicators 8 store discrete values of the frequency response received during each period of the disturbing signal from the output of divider 7 and discrete values of the frequency code received from the counter 17. Commands for writing to indicators 8 are received each period from the output of control unit 9 (Fig. 5 . At the output of R ((o) of indicators 8 there is a sequence of discrete values of the response Ri (b)}, and at the output of CO the sequence of ground values is codes K; proportional to the frequency CO; corresponding to R; co.

If during each 1 st period of the disturbing signal (Fig. 2 a) and the object signal p of the object to the disturbing signal (Fig. 28) p times equal parts of the periods of these signals, measure the instantaneous values of the disturbing signal L, | li reaction signal A, .-, then the value of the amplitude-frequency characteristic R; | (bk)) every moment

measurements

H can

define how

p .. (, and iiJiL .. K, j (0 | d,

(FIG.2 &)

to

where J is the instant of measurement of the instantaneous values of the disturbing signal and the reaction signal O: j P; P is the number of measurements for period j located within each period by its equal shares, equal to ucf f-Value (; (s;) for a period, defined as

R; (u; l

(co)

The noise immunity and accuracy on the definition of the frequency response will be more pronounced than - a greater number of measurements A, J; and A,: for the period, i.e. at r-oo. In this limiting case, we can write that Ri (u) for the period is equal to the ratio of the square of the reaction signal to the square of the disturbing signal, i.e.

Ri (ub

one

j / A einol / Ji

. ABOUT

t ---

j / A,; 5; ncol / di

If we write the value of the integral in the form of a integrand sum, then the value of the frequency response will be expressed as follows:

fi- S / An-ulj /)

Rih

4% P, ".4 t.

Since there is a limit amount,

can be written in

R

21/2 J - I

"Iji

/ A, ij /

those. the value of the amplitude-frequency characteristic is equal to the ratio of the modules of the sums of the instantaneous values of the reaction signal and the disturbing signal for the period of the disturbing signal.

Since during each period the disturbing signal A is measured in equal parts of its period, the same number of times, with a constant amplitude of the disturbing signal, the sum of the modules Aj, for a period is a constant value for all periods and does not depend on the frequency change and shift summation limits in two adjacent periods, i.e.

p r p

r-fS (/A.i / - z: / A ,, p + 1 p + 1

: ./A,;i(-Z / A, ii / -con5t j-2

Therefore, the value of the sum P,.

2; / A, j- enough to measure

 In the first period of the input signal and in further calculations, use as a constant value B. For the response signal, which varies depending on the dynamic properties of the object under study, in general the previous equality is not preserved, however, for two adjacent periods for which G) ; Wu, children fair equality

storms

P + K-1

. jT / i% / 4 / - f, /. j

/.

 V.6 .. the summation limits can be shifted within two adjacent periods (Fig. 3). 35

Thus, measurements of the instantaneous values of the reaction signal can be made at the moments of measuring the instantaneous values of the disturbing signal, in equal parts of the period of the disturbing signal, thereby eliminating the need to set the moments of measurement of the instantaneous values of the signal depending on the delayed signal. reaction signal from the disturbing signal.

The instantaneous value of the signal is reacted (.

And A-: can be obtained from the instantaneous values of the output signal

In the first period of the disturbance signal, control unit 9, via switch 3, connects a disturbance signal to the ADC input to obtain a constant B. At the command from the output of control unit 9 (Fig. 5 gl ASCH1 64 times during this period, it performs equal measurements and conversion The digital values of the instantaneous values of the disturbing signal A ,,;, A values are: in digital form, the ADC is fed to the first input of the adder 5. In the adder 5, a sum of 64 is formed during the period

H / A "; /

45

J

:one

the value of which is fed to the input of register 11 and is stored there until the end of the row.

Next, control block 9 skips five periods of the input signal to eliminate the effect of the transition process in the object under study and connects to the end of the package to the input

and"

subtracting from them the average value of the value of the post-50 ICP via switch 3, the output signal of the object under study.

In each i-th period of the input signal, the ADC, using commands from the output of control block 9 (Fig. 5), measures the instantaneous values of the output output component of the post about 2- "LP, after 1/64 55 of this period

, -. 1 g I

obtained in the pause (see Fig. 4b) when measuring p times the output signal during a pause.

 The device works as follows.

la apjjj. Values in digital

ten

five

0

five

(f

five

Sending a disturbing signal from the output of the generator 1 enters the object under study. During the pause, the control unit 9 through the switch 3 connects the output signal to the ADC input (Fig. 3e). The pause in duration is I / 32 periods of the frequency control signal. During this time, the ADC is in response to a command from the output of the control unit 9 (Fig. 3a) performs 32 measurements and converts the instantaneous values of the output signal AB |, into the digital code. These values are fed to

the first input of the adder 5, where the sum of 51 A b.,.

R., G

Dividing by 32 to obtain the average value of the constant component and "o. is carried out by shifting., the value of the NIN of the adder by five bits to the right. The obtained value U is the post of the second output of the adder 5 is fed to the input of the register 10, where it is stored until the end of the parcel.

In the first period of the disturbance signal, control unit 9, via switch 3, connects a disturbance signal to the ADC input to obtain a constant B. On command from the output of control unit 9 (Fig. 5 gl ASCH1 64 times during this period, in equal parts of it, measures and converts the digital form of the instantaneous values of the disturbing signal A ,,;, Values А:: the digital input from the output of the ADC is fed to the first input of the adder 5. In the adder 5, a sum of 64 is formed over a period

H / A "; /

J

:one

the value of which is fed to the input of register 11 and is stored there until the end of the row.

Next, control block 9 skips five periods of the input signal to eliminate the effect of the transition process in the object under study and connects to the end of the package to the input

la apjjj. Values in digital

71260873

The form from the A1D1 output goes to the first input of the adder 5, in which these values are added to the value of the post. arriving at the second input of the adder 5 in the additional code. Thus, at the output of the adder 5, a difference is formed

is equal to an internal dispute resolution key, and h control entered by the pom and d log and into the body of ind cnt control of the input of the anchor of the second input of the control of that input

- tJ

fast

 BUT

2.J

The modulus of this difference is fed to the input of the adder 6. In the adder 6 for each period of the input signal is formed the sum

64

 i i the value of which at the end of the period arrives at the first input of the divider 7. The second input of the divider 7 receives the value B. The output of the divider 7 each period is a discrete value of the amplitude-frequency characteristic R) (co), which goes to one of the inputs of the result indicators 8 and frequencies. At the other input of indicators 8 from the output of the counter 17 receives the digital code N; proportional to the frequency of the current period.

At the end of the parcel, the indicators 8 registers are stored (i pairs of values P; (") and N.; These values can be used for visual observation of the frequency response using two digital-to-analog converters and a two-coordinate plotter) or used for calculations on a digital computer management or identification tasks.

Formula

the invention

Claims (1)

I. A device for determining the amplitude-frequency characteristics of electrical power objects, comprising a tunable frequency generator, the first output of which is connected to the first input terminal of the device for connecting the test quadripole and the first input of the switch, the second input connected to the second terminal of the device for connecting the test four-terminal, switch output connected to the input of the analog-digital converter, the first output of the control unit is connected to the control input switch a, the second output of the unit up8 0 five 0 five 0 five 0 five 0 control is connected to the clock input of the analog-digital converter, the third output of the control unit is connected to the control inputs of the digital code divider and the tunable frequency generator, the second output of which is connected to the first input of the control unit, the output of the tunable frequency generator is connected to the first input of the result indicators, and frequency, and the fourth output of the control unit is connected to the control input of the first register, characterized in that, in order to increase the accuracy in terms of interference, in it s and two second register adder, the output of analog-to-digital converter through. serially connected first and second adders and a digital code divider are connected to a second input of result and frequency indicators, the control input of which is connected to a control input of a digital code divider, the output of the first adder is connected to the second input of a digital code divider, clock inputs of the first and second The second adders are connected to the clock input of the analog-digital converter, the second output of the first adder is via. the first register is connected to its second input, the control input of the second register is connected to the fifth output of the control unit, made with an additional output, the second control input is connected to the third output of the tunable frequency generator. 2; An apparatus according to claim I, characterized in that the tunable frequency generator is implemented in the form of a series-connected frequency control law setting unit and a controlled oscillator, the first and second inputs of which are the corresponding outputs of the tunable frequency generator, and its third output is connected to the first input of the counter , the second input of which is connected to the output of the pulse generator, the clock input of the counter is the control input of the tunable frequency generator, and the second output of the control law setting block The frequency control is the third output of the tunable frequency generator. % , but UpeoK. five   "about-  J l ..og OS ft: cfc ac Kl () (pas. 2 iwh tr 4V  I "N §  d HJ t-h "M X: Uynp . gh AllAt LGs AlpAtp and Outlet 15e In. For Vsh.11ga Bx.dff Bbix.sif Output dds Exit Bbix, 3f Ex. 93 and Editor A. Revin Compiled by L. Muranov, Tehred I.Popovich Proofreader, A. Tsko Order 5226/46 Circulation 728 Subscription VNII1GO State Committee of the USSR for inventions and discoveries 1) 3035, Moscow, Zh-35, Raushsk nab. 4/5 Production and printing company, Uzhgorod, st. Project, 4 ig. five