SU1603352A1 - Stabilized three-phase power supply system - Google Patents

Abstract

The invention relates to secondary power sources of radio equipment. The purpose of the invention is to improve the accuracy of the specified initial phase angles of higher harmonics by additional compensation of higher harmonics at the input of the square wave former. The goal is achieved by introducing into the circuit of two adders 2 and 8, the second block 12 of the transmission coefficient control, an additional voltage divider 14, a large-scale converter 20 and a wideband zero indicator 19. The introduction of these elements and the connections between them and allows for additional compensation of higher harmonics at the input of block 9. 1 Il.

Description

316

The invention relates to electrical engineering and can be used to create exemplary sources of industrial network parameters.

The purpose of the invention is to improve the accuracy of setting the initial phase angles of higher harmonics by additional compensation of higher harmonics at the input of the rectangular signal shaper.

The drawing shows a block diagram of a stabilized three-phase power system.

where K j. - the transmission coefficient of the block is maintained at a nominal level with high accuracy, since its output voltages through adjustable dividers 4-6 voltages are fed to the control inputs of the block 3 of the stabilizers, where they are compared with amplitude-related signals. Thanks to the large stabilization factor, the output voltages of the dividers 46 are maintained at almost the same level. The measuring node 7 indication of symmetry,

The device contains a three-phase g jy to the frequency of the main harmonic.

main harmonic generator 1 with zero drive, second adder 2, alternating voltage main harmonic stabilizer unit 3, adjustable voltage dividers 4-6, symmetry indication selective unit 7, first adder 8, driver 9 squares of pulses, frequency multiplier 10 , tunable multiphase generator 11, second transmission coefficient control unit .12, summing amplifier 13, additional voltage divider 14, exemplary phase meter 15, exemplary voltmeter 16, precision adder 17, first control unit 18 no gain, broadband light 19 and zero scaling converter 20 ..

The stabilized three-phase power system operates as follows. .

The three-phase generator 1 of the main harmonic forms a symmetrical three-phase voltage system:

20

25

thirty

35

40

monitors symmetry on the outputs at the outputs of dividers 4-6.

Reproduction of the normalized amplitude and initial angle of phase transition (NUSF) of higher harmonics relative to the main harmonic is considered using the Kth harmonic as an example.

At the initial moment of time, the output voltage of the divider 4 contains only the voltage of the main harmonics

 and „с, / Кст К, - sinCOt, (3) where К, is the transfer coefficient of the divisor 4,

which through the first output of the second adder 8 is fed to the input of the shaper 9 rectangular pulses

The former 9 generates rectangular pulses F along the zero harmonic transition, which are input to the multiplier 10, often with a multiplication factor N and the first input of a tunable multiphase generator 11, to the second input of which output pulses are output from the multiplier 1H. .

and,

Ut

(one)

and.

The voltage U through the first adder 2, and the voltage u0 and U directly go to the first, second and third inputs of the unit 3 of the main harmonics of the alternating voltage. Amplitude of output voltages of block 3 stabilizers

Upiax KcT sinCOt sin (63t

sin (cot +

2 l - -

3 25 t M

(2)

where K j. - the transmission coefficient of unit 3 is maintained at a nominal level with high accuracy, since its output voltages through adjustable dividers 4-6 voltages are fed to the control inputs of the stabilizer unit 3, where they are compared with the reference signals in amplitude. Due to the large stabilization factor, the output voltages of the dividers 46 are maintained at almost the same level. The measuring node 7 indication of symmetry, tuned to the frequency of the main harmonic.

20

25

thirty

35

40

45

50

monitors the symmetry of the voltages at the outputs of dividers 4-6.

Reproduction of the normalized amplitude values and the initial phase shift angle (NUSF) of higher harmonics with respect to the fundamental harmonic will be considered using the Kth harmonic as an example.

At the initial time, the output voltage of the divider 4 contains only the main harmonic voltage

 and „с, / Кст К, - sinCOt, (3) where К, is the transfer coefficient of the divisor 4,

which through the first output of the second adder 8 is fed to the input of the former 9 square-wave pulses.

The shaper 9 generates rectangular pulses F through the zero harmonic of the main harmonic, which are fed to the input of frequency multiplier 10 with a multiplication factor N and the first input of a tunable multiphase generator 11, to the second input of which output pulses 1P are pulses.

I

Using a tunable multiphase generator, we set the normalized amplitude values and the NUSF of the K-th harmonic, which through the second transfer efficiency control unit 12 is fed to the summing amplifier I 3.

From the output of the summation amplifier voltage 13

+ H to). C4)

Where

five

X Umaxt Kfy ein (Kot K is the gain of the amplifier 1 3, and Kf (Kj-T;

tf j, is the specified normalized value NUSF of the k-th harmonic;

and.

toch

 f

given normalized amplitude value of the Kth harmonic.

It is supplied to the input of an additional voltage generator 14, to the first input of the bi-phase power amplifier 15, to the input reference sample voltmeter 16 and to the fourth input of the precision adder 17. At the same time, from the first output of the tunable multiphase generator 11, K-Y signals are rectangular with zero the shift relative to the zero-transition of the main harmonic is fed to the second input of the reference phase meter 15.

If the specified amplitude values and NUSF are not equal to the indications of exemplary voltmeters 16 and phase meter 15, then with the help of the second transmission coefficient control unit 12, we correct these parameters so that the indications of exemplary instruments 15 and 16 correspond to the specified values.

At the same time, the voltage of the K-th harmonic is passed through the first transmission gain control unit 18 to the first adder 2, where the voltage of the main harmonic of phase A is summed up. Then, through block 3 of the main harmonic stabilizers,

and

 AN & UmaxKcfSi Wt + and „,, K„ x

X sin (KCOt + Lf) (5) is fed to the first input of the precision adder 17. If the readings of the 19 zero wideband indicator tuned to the harmonic frequency are not zero, then using the first block 18, the gain control is adjusted so that the readings indicator 1.9 were equal to zero.

If indicator 19 is zero, the highest harmonic voltage of the main and compensation channels is Umq.-K./sin(KOt H-tf,), to KcmH

X sin (KG) t + q,),

(6)

According to equation (6), the specified normalized amplitude values and the highest harmonic NUSF at the first input of the precision adder 17 are equal to the indications of exemplary devices.

However, to set the normalized amplitude values and high harmonic NUSFs, some time is required, at the moment of which a portion of uncompensated voltage K-th will be present at the input of the driver 9

harmonics, which will lead to a shift of the zero harmonic of the main harmonic and the collapse of a tunable multiphase generator II.

When setting the normalized amplitude value and high harmonic NUSF, the voltage

and - Un, "; Kej K. sinCKCOt -Hf,),

where Kg is the transfer ratio of the divider 14,

from the output of the additional divider 14 is fed to the first input of the second summator, to which the voltage goes through the first adjustable divider 4

20

V.-R K; sinwt +

. sin№at + ey,).

(eight)

When the indicator 19 is zero, only the main harmonic voltage will be present at the input of the former 9, i.e. The sum of 25 voltages according to formulas (7) and (8) will be equal to:

and and ",. To,. To, sin cot -n C,", x

X (KCOt + C)) - and „d, K, x 30 X K.sin (Ka) t + (f,) Un ,.

X K, sin cot.

(9)

45

If the higher harmonic voltages supplied to the first input of the second adder 8 from the outputs of dividers 14 35 and 4 are not equal, then the voltage at the input of the shaper 9 is equal to:

and "Up, (,, K" - K, sin CO t + Un, a, X x (K "K, - K K) sin (KUt + Cf,). (10) To fully compensate the voltage of the K-th harmonics at the input of the driver 9 with a precision adder uncompensated voltage of the K-th harmonic

G, - (K n-Kcy) sin (Ku)

(eleven)

is fed to the input of the scaling converter 20, from the output of which the voltage is 50 Li, p - from

X sin (KCOt "-C,), where K, is the transfer coefficient of the converter 20, and K K ,,

 is fed to the second input of the second adder 8.

Summing the voltages using formulas (10) and (12), we get:

f U, Kc, -K, 8inu) t + and „„, (K, / x

K, (KQt + Cf), (Kcr- Kc) Kj8in (KOt +1) 5

-U, "at Ke, -K, 8inCOt.

Thus, the use of the scale of the converter 20, the second adder 8, the second transmission coefficient control unit 12 and the additional voltage divider 14 makes it possible to increase the high harmonic NUSF values.

Claims (1)

Claim 5 25 Stabilized three-phase power supply: a power supply containing a three-phase main harmonic generator with zero drive, a block of main harmonic amplifiers, a selective node Symmetry indications, first, second, and third adjustable voltage dividers connected between the respective outputs and inputs of the control stabilizers amplitudes. main harmonics, sequentially connected square pulse shaper, frequency multiplier AND tunable multi-phase high harmonic generator, k t The KOTOpot O input is connected to the output of a square pulse shaper, a first gain control unit and a compression amplifier, the first and second outputs of the three-phase main harmonic generator are connected to the corresponding inputs of the amplitude stabilizer block of the main harmonic, the outputs of adjustable voltage dividers are connected to selective inputs node indicator-. of symmetry, about t and h and shch a - so that in order to improve the accuracy of the normalized values of the phase shift angles of higher harmonics, main harmonics by additional compensation of higher gaomonics at the input of a rectangular signal shaper at the zero harmonic transition, a second gain control unit, first and second adders, an additional voltage divider, an exemplary phase meter, an exemplary i voltmeter, precision adder, scaling converter and wideband zero indicator, while the outputs of the block of amplitude stabilizers of the main harmonic are connected to the corresponding inputs of precision The adder, the output of which is connected to the input of the wideband zero indicator and the input of the scaling converter, the output of which is connected, to the first input of the first adder, the second input of which is connected to the outputs of the first adjustable divider and additional voltage divider, the output of the first adder is connected to the input of the rectangular pulses, N first outputs of tunable multi-phase generator through the first transmission coefficient control unit connected to the corresponding inputs of the second M35 40 45 and through the second transmission coefficient control unit to the corresponding inputs of the summing amplifier, the output of which is connected to the input of an additional voltage divider, the first input of the reference phase meter, the input of the reference voltmeter and the corresponding input of the precision adder, the second input of which is connected to the second the output of a multiphase generator, with the third output of a three-phase main harmonic generator connected to the corresponding input of the main harmonic stabilizer block Without the second adder. and through the second transmission coefficient control unit to the corresponding inputs of the summing amplifier, the output of which is connected to the input of an additional voltage divider, the first input of the reference phase meter, the input of the reference voltmeter and the corresponding input of the precision adder, the second input of which is connected to the second the output of a multiphase generator, with the third output of a three-phase main harmonic generator connected to the corresponding input of the main harmonic stabilizer block Without the second adder.