RU2291564C1 - Device for transferring and receiving signals in three-phased electric transfer line - Google Patents

Abstract

FIELD: electric engineering, possible use during organization of communication channels using three-phased electric networks (0,4-35)kV without processing thereof with high frequency rejecters.

SUBSTANCE: device for realization of disclosed method contains average voltage line 10 kV, transformers 10/0,4 kV in stations of transfer and receipt, lines 0,4 kV in receipt and transfer stations, voltage filters of symmetric components of direct and reverse order in receipt station, phase shifter, adder, narrowband filter in receipt station, transmitter in transfer station.

EFFECT: production of one-channel receipt of signals on one frequency f₀, while increasing signal/noise ratio 2,8 times, in comparison to prototype.

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Description

The invention relates to electrical engineering and can find application in organizing communication channels using three-phase power lines (0.4-35) kV without processing them with high-frequency chokes. Achievable technical result - obtaining a single-channel signal reception at a single frequency f _c with increasing signal-to-noise ratio.

A known method of transmitting and receiving signals in a three-phase power line, which is adopted as an analogue and implemented in the device: K.I. Gutin, thesis for the degree of candidate of technical sciences "Improving the efficiency of information transfer in rural electric networks with a voltage of 10 kV" M., 1987, VNESH, p.145 [1]. In this method, the signal currents are introduced alternately at the transfer point into the phases AB, BC, CA, VA, CB, AC, etc. in accordance with the opening of the diodes of the three-phase half-wave bridge of the transmitter. The time interval Δt when currents are introduced into the phases AB, BC, CA, etc., is equal to:

период частоты промышленного напряжения, где F=50 Гц, при этом в трехфазной сети образуют токи симметричных составляющихWhere:

the frequency period of the industrial voltage, where F = 50 Hz, while in a three-phase network they form currents of symmetrical components

- токи сигналов симметричных составляющих обратной последовательности АСВ на частоте f₁;

- токи симметричных составляющих прямой последовательности АВС на частоте f₂;

- действующее значение токов в фазах;Where:

- currents of signals of symmetrical components of the ACB reverse sequence at a frequency f ₁ ;

- currents of symmetrical components of the direct sequence ABC at a frequency f ₂ ;

- current value of currents in phases;

where: f ₁ = f ₀ -F, f ₂ = f ₀ + F

и

передают в пункт приема сигналов, который гальванически связан с пунктом передачи.Toki

and

transmit to the point of reception of signals, which is galvanically connected with the point of transmission.

и

в пункте приема сигналов образуют напряжения симметричных составляющихToki

and

at the point of receiving signals form the voltage of the symmetrical components

,

,

- действующее значение напряжения сигналов между фазами В и С. Известно, что двухканальный прием дает выигрыш отношения сигнал/помеха в √2 раз, чем прием сигналов в одном канале [1, стр.83]. Недостатком данного способа является низкое отношение сигнал/помеха и наличие двухканального приема.which respectively receive voltage filters of signals of symmetrical components of the negative sequence (FNTSOP), which is tuned to the frequency f ₁ , and direct sequence (FNSSP), which is tuned to the frequency f ₂ . The voltages from the outputs of the FNTSOP and FNTSPP, respectively, are applied to the inputs of narrow-band filters (UPF), which are respectively tuned to frequencies f ₁ and f ₂ . Further signal processing is performed by one of the known methods, where:

- the actual value of the signal voltage between phases B and C. It is known that two-channel reception gives a gain of the signal-to-noise ratio by √2 times than the reception of signals in one channel [1, p. 83]. The disadvantage of this method is the low signal to noise ratio and the presence of two-channel reception.

A known method and device for transmitting and receiving signals in a three-phase power line, which is adopted as a prototype. This method corresponds to the operation of an analogue, when inputting signal currents into two phases of a 0.4 kV line [1, p. 68-69].

When entering the signal currents in the prototype in two phases, for example B and C, the 0.4 kV lines at the transmission point form four signal currents of symmetrical components [1, p. 69].

At a frequency f ₁ = f ₀ -F

On frequency

f ₂ = f ₀ + F

These currents at the signal receiving point form four voltages of symmetrical components at frequencies f ₁ and f ₂

At a frequency f ₁

At a frequency f ₂ = f ₀ + F

и

соответственно принимают на ФНССОП и ФНССПП, которые соответственно настроены на частоты f₁, с выходов которых напряжения подают на входы узкополосных фильтров (УПФ), которые настроены соответственно на частоты f₁ и f₂. Дальнейшую обработку сигналов производят одним из известных способов. В первом канале принимают напряжение сигналаStress

and

respectively, they are received by the FNTSOP and FNTSPP, which are respectively tuned to frequencies f ₁ , from the outputs of which voltages are fed to the inputs of narrow-band filters (UPF), which are tuned to frequencies f ₁ and f _2, respectively. Further signal processing is performed by one of the known methods. In the first channel, the signal voltage is received

In the second channel, the signal voltage is received

и

, делаем вывод, что в прототипе принимаемые напряжения и

(6) и (7) меньше в √3 раз, чем в аналоге. Это объясняется тем, что в прототипе напряжения

и

не могут быть приняты и являются паразитными, на создание которых расходуют энергию передатчика. В прототипе как и в аналоге производят двухканальный прием, что повышает отношение сигнал/помеха в √2 раз. Недостатком данного способа является низкое отношение сигнал/помеха и наличие двухканального приема, что экономически нецелесообразно, а также снижает вероятность отказа приема сигналов, так как при выходе из работы одного из двух каналов приема выходит из строя весь приемный тракт.Comparing the values of the received stresses in the analogue of (3) with

and

, we conclude that in the prototype the received voltage and

(6) and (7) are √3 times less than in the analogue. This is because in the prototype voltage

and

cannot be received and are parasitic, the creation of which consumes transmitter energy. In the prototype, as in the analogue, two-channel reception is performed, which increases the signal-to-noise ratio by √2 times. The disadvantage of this method is the low signal-to-noise ratio and the presence of two-channel reception, which is economically impractical, and also reduces the likelihood of signal reception failure, since when one of the two reception channels fails, the entire receiving path fails.

The aim of the invention is to increase the signal-to-noise ratio with single-channel signal reception.

The drawing shows a diagram of the transmission and reception of signals in a three-phase power line, which implements the claimed technical proposal.

1 - Medium voltage line (10 kV);

2 - Transformer 10 / 0.4 kV at the transfer point;

3 - Low voltage line (0.4 kV) at the transmission point;

4 - Transmitter;

5 - Transformer 10 / 0.4 kV at the receiving point;

6 - 0.4 kV line at the receiving point;

7 - FNTSPP, which is tuned to the frequency f ₂ ;

8 - FNSOP, which is tuned to a frequency f ₁ ;

9 - Phaser;

10 - adder;

11 - UPF, which is tuned to the frequency f ₀ .

DESCRIPTION OF THE WORK DIAGRAM OF THE PROPOSED TECHNICAL PROPOSAL

As a transmitter in the claimed technical proposal, a generator is used, which is used in the "Gutin K.I. Method of inputting signal currents into a three-phase power line". At the point of transmission, the signal currents as in the prototype are introduced into two phases B and C of the line 0.4 kV - 3, but not at two frequencies f ₁ and f ₂ , but at one frequency f _about . [Patent RU 2224365 C2 of 04/20/04, Bull. No. 2].

At the information input of the transmitter 4, a sequence of encoded video pulses is supplied, which contains information about the parameters of the controlled and managed object in the form of telecontrol signals (TU), tele-signaling (TS), tele-measurements (TI). From the output of the transmitter 4, the signals in the form of radio pulses that are filled with a high frequency f ₀ are introduced into the phases of the 0.4 kV V and C - 3 lines, of a transformer 10 / 0.4 kV - 2, while in three phases 0.4 kV receive four currents of symmetrical components as in the prototype

In the claimed technical proposal we have:

We replace in (6) and (7) the frequencies f ₁ and f ₂ with the frequency f ₀ :

In (12) we group the currents of identical sequences:

Denote the currents in (13):

The currents (14) from the 0.4 kV - 3 network are transformed from the transfer point to the receiving point via 10 / 0.4 kV 2 and 5 transformers into a 0.4 kV - 6 network, where they form the voltage:

At the output of the FNTSPP - 7 receive a voltage proportional to the voltage of the symmetrical components of the direct sequence

At the output of the FNTSOP - 8, a voltage is obtained proportional to the voltage of the symmetrical components of the negative sequence

The voltage (16) is fed to the input of the phase shifter 9, where the phase shift φ ₁ values

The output of the phase shifter 9 receive the voltage:

The voltage (19) is supplied to the first input of the adder 10, the voltage (17) is supplied to the second input of the adder 10, from the output of which a voltage with double amplitude is obtained:

The voltage (20) is fed to the input UPF - 11, which is tuned to the frequency f _c . At the output of the UPF - 11, which is informational, a sequence of encoded video pulses of signals TU, TS, TI is obtained, which corresponds to a sequence of video pulses at the information input of transmitter 4. Next, the signals are processed using one of the known methods.

COMPARISON OF SIGNAL / INTERFERENCE RATIO VALUES IN ANALOGUE, PROTOTYPE AND PROPOSED TECHNICAL PROPOSAL.

ANALOGUE

The signal voltages in channel 1 and channel 2 according to (3) are equal to:

Given the increase of √2 times the signal voltage due to two-channel reception, the signal voltage is:

PROTOTYPE

а в канале 2 напряжение

а также с учетом увеличения в √2 раз напряжения сигнала за счет двухканального приема, который осуществлен в прототипе, напряжение сигнала равно:The voltage of the signals in channel 1 and channel 2 according to (4) and (5), taking into account that they accept voltage in channel 1

and in channel 2 voltage

and also taking into account an increase of √2 times the signal voltage due to the two-channel reception, which is carried out in the prototype, the signal voltage is equal to:

STATED TECHNICAL OFFER

The voltage of the signals of the forward and reverse sequences at a frequency f _about according to (15) are equal to:

Given the fact that the output of the adder 10 have an increase in signal voltage by a factor of 2, according to (20), the signal voltage is:

We take the interference voltage in the analogue, prototype and the claimed technical solution the same and equal:

where: K <1.

We define the signal-to-noise ratio - h:

In the analogue in accordance with (21) and (25):

In the prototype in accordance with (22) and (25):

In the claimed technical proposal in accordance with (24) and (25):

Thus, the signal-to-noise ratio h in the claimed technical proposal is larger compared to the analogue, taking into account (26) and (28) in:

in comparison with the prototype, taking into account (27) and (28) in:

We have proved that the goal set by the invention has been achieved.

A single-channel signal reception at a frequency f _{0 was} obtained with a simultaneous increase in signal / noise compared to the analog by 1.63 times and the prototype by 2.8 times.

NOTE: when describing the operation of the circuit (drawing), the following assumptions were made:

1. The coefficient of the transmission path of the signal currents from the transmitter - 4 to the receiving filters 7 and 8 is taken equal to unity.

2. The transmission coefficients of the elements 7, 8, 9, 10, 11 are taken equal to unity.

и напряжениях

обозначают:Designation in the text of the description of the invention: indices at currents

and voltages

denote:

1 - direct phase rotation ABC;

2 - reverse phase rotation of the ACB;

1 Σ is the total current of the direct sequence;

2 ∑ is the total current of the reverse sequence;

an - currents and voltages in the analogue;

pr - currents and voltages in the prototype;

3 - currents and voltages in the claimed technical proposal;

f ₀ - signal frequency (frequency of filling video pulses)

F = 50 Hz - frequency of industrial voltage;

f ₁ = f ₀ -50; f ₂ = f ₀ +50; ω ₀ = 2πf ₀ .

U _m is the voltage amplitude, respectively, from the outputs of the FNTSPP 7 and FNSOP 8;

U (t) ₁ is the voltage at the output of the Federal Tariff Regulation System 7;

U (t) ₂ is the voltage at the output of the FNTSOP 8;

U (t) _phases - voltage at the output of the phase shifter 9;

U (t) _sum - voltage at the output of the adder - 10.

h _analogue is the signal-to-noise ratio in the analogue.

h _prototype - signal-to-noise ratio in the prototype.

h _declared - signal-to-noise ratio in the claimed technical proposal.

Claims (1)

A method of transmitting and receiving signals in a three-phase power line, in accordance with which a sequence of coded video pulses, which contains information about the parameters of the monitored and controlled object in the form of telecontrol signals (TU), tele-signaling (TC), telemetry ( TI), the transmitter fill said video pulses of high frequency current signals f _0, to afford the radio pulses, characterized in that RF pulses with a transmitter output odyat in two phases B and C voltage 0.4 kV transformer 10 / 0,4 kV set forth in paragraph signaling currents, the currents obtained

signals of symmetrical components of a direct sequence at a frequency f ₀ and signal currents

symmetrical components of the negative sequence at a frequency f ₀ , signal currents

and

a three-phase line with a voltage of 0.4 kV is transmitted to the receiving point along the circuit - a 10 / 0.4 kV transformer at the transfer point - a three-phase line of 10 kV voltage - a 10 / 0.4 kV transformer at the receiving point is a three-phase 0.4 kV line reception point where they form a voltage

symmetrical components of the direct sequence at a frequency f ₀ and voltage

symmetrical components of the negative sequence at frequency f ₀ voltage

take the voltage filter of the symmetric components of the direct sequence (FNSSPP), which is tuned to a frequency f ₀ , the voltage

receive the voltage filter of the symmetric components of the negative sequence (FNTSOP), which is tuned to the frequency f ₀ , at the output of the FNTSPP receive a voltage U (t) ₁ proportional to the voltage

U (t) ₁ = U _m (cos ω ₀ t + φ ₁ ), at the output of the FNTSOP receive a voltage U (t) ₂ proportional to the voltage

U (t) ₂ = U _m (cos ω ₀ t + φ ₂ ), the voltage U (t) _{1 is} fed to the input of the phase shifter, where the phase shift φ ₁ to the value φ ₁ = φ ₂ , at the output of the phase shifter receive voltage U (t) _phases = U _m (cos ω ₀ t + φ ₂ ), the voltage U (t) of the _{phases is} applied to the first input of the adder, to the second input of which the voltage U (t) ₂ is applied, the voltage with double amplitude is obtained at the output of the adder: U (t) _sums. = 2U _m (cos ω ₀ t + φ ₂ ), which is fed to the input of a narrow-band filter (UPF), which is tuned to the frequency f ₀ , at the output of the UPF, which is informational, a sequence of encoded video pulses is obtained, which corresponds to a sequence of encoded video pulses at the information input of the transmitter, then the signals are processed in one of the known ways, where the indices at signal currents

and signal voltages

indicate: 1 - direct phase rotation of ABC; 2 - reverse phase rotation of the ACB; ω ₀ = 2πf ₀ ; φ ₁ and φ ₂ phase shifts respectively in voltages U (t) ₁ and U (t) ₂ ; U _m is the amplitude of the stresses U (t) ₁ and U (t) ₂ .