JPH03503470A - Device for transmitting signals through three-phase distribution lines - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Device for transmitting signals over three-phase distribution lines Field of invention The present invention provides an audio frequency voltage and a and current transmission, in particular the transmission of signals through the conductors of three-phase distribution lines. It relates to a device for

This equipment is used from a controllable station located on the low voltage side to a load distribution center at a distribution sub-station. It is used when transmitting signals.

This controllable station is used for substations, terminal line loads, and network division nodes in three-phase distribution networks. It is an automatic standby switching station.

Background technology A device designed to bring signals to two phases for transmission through the conductors of a three-phase distribution line. location is known (USSR inventor certificate no. 860274 and no. 1019649) .

A common drawback of these conventional devices is that they cannot function in the event of a break in the phase carrying the signal current. (incomplete phase 9).

Furthermore, due to the loss of operating conditions under incomplete phase conditions, information about this emergency situation is cannot be transmitted. The conventional device described above also has an imperfect phase on the installation side of the device. It is also important that the occurrence of the condition cannot be detected.

The maximum level of disturbances in the communication channels established through the conductors of the power distribution network. One of the fractions is a harmonic of the main frequency. The main cause of such disturbances is the load impedance the nonlinearity of the transformer and the voltage-current characteristics of the main transformer. Many countries, including the United States, We are developing means to suppress harmful harmonics (for example, Russell and J.D. Ouan, “Harmonic Noise Control in Distributed Line Communications” Elimination J, IEEE Transactions on Power Dispute Apparatus and Systems , 1,985, PAS-104, No. 12, pp. 333B-3344) .

This document shows a method of suppressing high frequency interference, and it is important to create a interference suppression device. This shows the possibility in principle. This research is continuing. No interference suppression When the signal voltage (flS current) is maintained at a level that exceeds the level of the interference noise, the signal voltage (flS current) is The signal/noise ratio shall be sufficient to give reliable reception of a particular signal. However, this requires the use of a high-power transmitter.

Also, the device if (SUA 1223381) has three inductance coils and three first and third inductance coils. The first conductor of the inductance coil consists of two diodes and a switch. are connected to phases A, B, and C of the distribution line, respectively, and the second conductor is connected to the anode of the first diode. The cathodes of these diodes are connected to each other and to the above switch. The second power of this switch is connected to the anode of the second diode. and the cathodes of each of the second diodes are connected to a common point of The above switch is directly connected to the thyristor and the second inductance coil. , a Cyrisk ignition unit, a capacitor, and a resistor. The input signal is connected to the anode of the thyristor and the first pole of the capacitor through the resistor. Connect the second pole of this capacitor to the second power of the above switch and the second inductor. The second conductor of this second inductance coil is connected to the first conductor of the coil. The above thyristor ignition unit is connected to the cathode of the thyristor. Connected across the pole and cathode.

This device has the ability to operate under imperfect phase conditions, but with the fundamental wave as the signal current. Current harmonic components are characterized by a large number of harmonic components that consume power supply energy. .

Furthermore, under imperfect phase conditions the received signal current is halved, making the receiver less susceptible to interference. lowers immunity.

This device includes an ignition unit as its switch, a first inductance coil, Using a cyrisk with a capacitor and a resistor.

During the time interval, phase A is at a higher potential than phase C, and control of the When the ignition pulse from the unit enters the control electrode of the Cylisk, the current passes through the flows through this thyristor. That is, to the phase - the first inductance coil - the first duct Iode - Resistor - Thyristor 1st inductance coil - 2nd diode - Phase C0 The instantaneous value of this current is as follows.

However, Eo is the DC component of the rectified three-phase voltage, R is the ohmic resistance of this current path, and L is the inductance of this current path, and t is the conduction time interval of the sirisk. .

The time interval during which the thyristor conducts is given by the following formula, where T -1/fo , , f o is the switch key frequency.

Using equation (2), equation (2) becomes as follows.

However, I is the current amplitude at t-τ.

The ohmic resistance R of this current path is reliable when the time interval O≦t≦To/4. The sinusoidal waveform of the signal current is chosen to be maximum, in which case equation (1) becomes: Ru.

i-1 sin ωot (4) where ω-2fo is the angular frequency.

This thyristor is a forced switch consisting of a capacitor and a first inductance coil. It is cut off by the action of the circuit.

This capacitor is connected to the interval T/4≦t≦To (Size 20 charged when the lister is cut off) Phase A - 1st inductance coil - 1st diode - resistor - capacitor 2nd da The charging of the iode-phase C0 capacitor is completed at t-r O/2 and this time The road is T. The period of /2≦t≦To is stable. t-Ton(n-1゜2.3・ ), the next ignition pulse enters the control electrode of the thyristor, and the cycle ends. repeated. Is it possible to pass resistance in this way? The lS flow is as follows.

The fundamental wave is a signal current. When formula (5) is Fourier expanded, Therefore, the basic current (signal current) is and the effective signal current is becomes. From Equation (6), this well-known device only has a useful signal current (Equation (7)). In addition, currents with frequencies of 2ωD, 4ω0°, etc. are also generated, and these high-frequency currents are used as a power source. , i.e. in this case by drawing additional power from the three-phase power supply. This reduces the efficiency of the device in terms of the active power delivered to the broadcast cables; It will look like this:

However, Z is the input impedance of the distribution line. On the other hand, the effective signal excluding harmonic components is The number power is as follows.

Therefore, equation (11) is a well-known device that generates harmonics along with the effective fundamental frequency current. shows that compared to equipment that does not generate harmonics, the amount of active power is one-fourth of the active power. There is.

The known device generates signal currents of frequencies f1 and f2, i.e. , where fo is the first frequency and F is the main frequency.

Two receivers are therefore required. Such a configuration has harmonic interference compared to noise. For example, it is unsuitable for receiving signals in the 10 KHz-12 KHz frequency band. So Frequency bands such as are used for short-distance 11i1 (up to 3-) communications created using power transmission lines. Most unsuitable for links.

In such cases, it is best to use one receiver tuned to fo, the key frequency. stomach.

Disclosure of invention The invention is based on the problem of creating a device for transmitting signals over three-phase power lines. The thyrist provides improved disturbance insensitivity in the event of a rupture of any phase of a three-phase transmission line. by controlling the off-state period of the transmitter and the transmission line connecting the receiver and transmitter. detection of incomplete phase states by enabling elements of the receiver; and the frequency band where the disturbance level due to harmonics of the mains voltage is proportional to the fluctuating noise. Suppresses interference from harmonic components of the main voltage (current), which is fluctuating noise in the received signal. This is done by receiving the key frequency signal.

This object of the invention is to connect a receiver and a power line to carry out signal transmission through a three-phase power line. This is accomplished by a device consisting of a transmitting unit having a The transmitting unit includes three first inductance coils, three first inductance coils and three first inductance coils. The first inductance coil is composed of a second diode and a switch. 1 conductor is connected to the respective input of the transmitting unit and the 2nd of the 1st inductance coil The conductor is connected to the anode of the first diode, and the cathodes of these diodes are common point and connect to the first power of the switch, and the second power of this switch is connected to the interconnected anode of the second diode and connected to the cathode of the second diode. are respectively connected to the respective inputs of the transmitting unit, and the above switches are connected to the respective inputs of the transmitting unit. This device features an element that controls the It has a complete phase condition detection unit, and the receiving unit includes a symmetrical element filter circuit and and a narrowband filter circuit.

This suppresses harmonic interference to allow signal reception and prevents breakage of any phase of a three-phase transmission line. In the section of the power line connecting the receiver and transmitter unit, This makes it possible to detect incomplete phase conditions at guarantees signal reception at the key frequency when operating in a frequency band proportional to that of the Ru.

a respective second duct to a respective input of the transmitting unit via a first inductance coil; The cathodes of the diodes are often connected, and these cathodes of the second diode and the first The corresponding art of diodes are interconnected at common points and the capacitance between these common points is A coupling is provided to form a tuned circuit with the first inductance coil, and the switch The unit includes the thyristor, the second inductance coil, the thyristor ignition unit, and the first coil. The first switch input is connected to the thyristor via this resistor. the anode of the first capacitor and the first plate of the first capacitor; The second plate is connected to the first conductor of the second inductance coil, and the second plate is connected to the first conductor of the second inductance coil. a second conductor of the thyristor coil is connected to the cathode of the thyristor and a second switch input; The thyristor ignition unit is located between the thyristor control electrode and the thyristor cathode. connected to.

This is generated by the transmitting unit by removing harmonics in the signal current. This improves the waveform of the signal current, thereby reducing power consumption by a factor of four.

Also, the cathode of the second diode and the corresponding anode of the first diode are common. It is advisable to provide capacitive coupling between the points in the form of three second capacitors in a star or delta connection. .

This star connection requires a second capacitor of capacitance C at the U line voltage of the main frequency, The Δ connection requires a second capacitor with a capacitance of 3C at U/2'@voltage of the main frequency.

The switch closure period is further controlled by a relay having an input connected to the control input of the switch. It is good to control.

In this case, the normally closed contacts of the relay are in parallel with the section of the second inductance coil. Connect to.

The normally open contacts of this relay are also paralleled to the second capacitor via the third capacitor. Connecting.

This makes the receiver insensitive to interference by increasing the signal current to a certain high value. This is improved under incomplete phase conditions on the transmitting unit side.

It is best to configure the incomplete phase condition detection unit with a symmetrical filter. Input is first. Connect to each first conductor of the inductance coil, and its output has a narrow The input of a bandpass filter is entered, and the output of this narrowband filter drives the input of the amplifier. , connect to the output of this amplifier or the switch control input.

This creates a direct phase sequence filter tuned to the difference between the key frequency and the main frequency. It can now be used as a symmetric filter.

This allows detection of unsafe metal conditions on the transmitter side and controls the relay. This makes it possible to generate a signal.

Furthermore, it is preferable to configure this symmetrical filter network with a first and a second symmetrical filter. The inputs of these first and second symmetrical filters are connected to the input of the receiving unit. , the first symmetrical filter is tuned to the difference between the key frequency and the main frequency, and the second symmetrical filter is tuned to the difference between the key frequency and the main frequency. The signal is tuned to the sum of the key frequency and the main frequency. The narrowband filter network is It is preferable to consist of a first and a second narrow band filter of the wave number, and their input is Connected to the outputs of the first and second symmetrical filters, the outputs drive the inputs of the comparator gates. do.

The inputs of the first and second symmetrical filters can be connected directly to the inputs of the receiving unit. Often, a first symmetrical filter performs antiphase sequential filtering, and a second symmetrical filter performs direct filtering. Used for tangent order filters.

Two phases are alternated between the inputs of the first and second symmetrical filters and the input of the receiving unit. It is best to electrically connect the rectifier switch so that the first symmetrical filter The second symmetrical filter performs filtering in reverse phase order.

It is also preferable to connect the transmitting unit directly to the power transmission system.

The transmitting unit can be electrically connected to the power line by means of a first three-phase transformer, which The primary winding of is connected to one phase of the transmission line and the secondary winding is connected to the input of the transmitting unit.

The connection of the power transmission unit to the power line may be direct or via a three-phase transformer; The primary winding of this transformer is connected to multiple phases of the transmission line, and the secondary winding is connected to the receiving unit. The first and second symmetrical filters function as voltage filters.

first and second symmetrical filters with first and second narrowband filters and comparator gates; By using a dual channel transmitter, the interference of harmonics of the main frequency can be suppressed while receiving dual channel signals. signal reception, thus reducing the signal-to-noise of the received signal voltage across the load. Improve the sound ratio.

It is recommended to connect the receiving unit to the power line by means of three current transformers, one of which The secondary windings are connected in series to each phase of the transmission line, with the first conductor of the secondary winding being grounded and the The two conductors are each connected to an input of the receiving unit.

In this configuration, the current filter can be used as the first and second symmetrical filters, which This allows a balance capacitor to be used to balance the signal voltage at the power substation. signal can be received in the form of load current. Using the current filter as a symmetrical filter By doing so, the signal-to-noise ratio of the received signal can be made higher.

Symmetrical filter network configured with three third and three fourth diodes and a converter The cathodes of the third diode are then often connected to each other and to the primary winding of the converter. connect to the first conductor of the wire, the cathode of the third diode and the anode of the third diode are connected to each other at a common point and directly to the input of the receiving unit. The bandpass filter has an input driven by the secondary winding of the transducer and has a key frequency and a third narrowband filter tuned to the number.

The connection of the cathode of the third diode to the first conductor of the transformer primary winding is connected to another resistor or is provided by the fourth capacitor.

This makes it possible to receive signals at key frequencies, simplifying the design of the receiving unit. It will be done. This configuration is designed so that the signal frequency is such that the harmonic interference signal level is proportional to the fluctuating noise. Suitable for use within the wave number range (10KHz-12KHz).

Brief description of the drawing These and other objects of the invention will be apparent from the detailed description of the preferred embodiments with reference to the following drawings. It becomes clear from the light.

Figure 1 shows a three-phase power transmission line according to the present invention, one with capacitive coupling and one with relay contact connection. 2 shows two embodiments of a device for signal transmission via.

FIG. 2 shows the anode of the first diode corresponding to the cathode of the second diode according to the present invention. 3 shows another example of capacitive coupling between common points of the nodes.

Figure 3 shows the connections of the relay in the circuit for controlling the switch opening period according to the present invention. Next, another example will be shown.

FIG. 4 shows an embodiment of a receiving unit according to the invention.

FIG. 5 shows an embodiment of a transmitting unit coupled to a three-phase power line according to the present invention.

FIG. 6 shows an embodiment of a receiving unit coupled to a three-phase power line according to the invention.

FIG. 7 shows another embodiment of a receiving unit according to the invention for coupling to a three-phase transmission line. .

FIG. 8 shows another embodiment of the receiving unit of the present invention.

FIG. 9 shows still another embodiment of the receiving unit of the present invention.

Figure 10a), b), c), d) shows the base of the signal current applied to the three-phase transmission line. a), b) - under normal operating conditions of the power transmission line; c), d) - under incomplete phase conditions of the transmission line.

FIG. 11 shows the waveform of the 13th harmonic interference signal.

FIG. 12 shows the waveform of the 17th harmonic interference signal.

BEST MODE FOR CARRYING OUT THE INVENTION The device for signal transmission through the conductors of a three-phase transmission line (Fig. 1) is an input device connected to the transmission line 3. It consists of a receiver 1 and a transmitter unit 2, each having a power. There are 3 transmitting units 2 first inductance coils 41, 42, and 43, and three first diodes 5□, 5°, 53 and three second diodes 61.6. ,．． Consisting of 63 and switch 7 . The first conductive wire of the first inductance coil 41, 42, 43 is the husband of the transmitting unit 2. The second conductor wires of the first inductance coils 40, 4°, and 43 are connected to the respective inputs. Connect to the anode of 1 diode 5□15°253. The cassette of these diodes The respective leads are connected to a common point and to the first power source of the switch 7. switch The second power of 7 should be connected to the common point of the second diode 64.6° and the anode of 63. Their cathodes are connected to respective inputs of the transmitting unit 2.

The switch 7 is designed with a closed state period control element 8. This device also It has an unsafe phase condition detection unit 9, and the receiving unit 1 has a symmetrically arranged filter network. 10 and a narrowband filter circuit 11.

The second diode 6, . 62.63 to the input of the sending unit 2 of the cathode respectively. Electrical coupling is provided by the first inductance coil 4. ．． 42.43. Second Cathodes of diodes 6□, 6□, 63 and corresponding first diodes 5□, 5 ゜, 53 anodes are connected to a common point, and the capacitive coupling between these common points is an inductor. Together with the coils 41.4° and 43, a tuning circuit is formed. switch 7 is siris 12, the second inductance coil]-3, and the Cyrisk ignition unit 14. , a first capacitor 15 and a resistor 16. The first human power of switch 7 is resistor 16 connected to the anode of the thyristor 12 and the first plate of the capacitor 15 through the The second plate is connected to the first conductor of the second inductance coil 13, and the second plate is connected to the first conductor of the second inductance coil 13. The second conductor is connected to the cathode of the thyristor 12 and the second power of the switch 7. rhinoceros Lister ignition unit 141. +Connected between the control electrode and cathode of thyristor 12 do.

The first diode 5□, 5゜, 53 corresponds to the second diode 6□, 6゜, 63. Capacitive coupling between the common points of the anodes is provided by three second capacitors 17□ connected in a star shape.

17°, 173.

The first diode 5□15□, 53 corresponding to the second diode 6□, 6°, 63 The capacitive coupling between the common points of the anodes is determined by the three second nodes connected in a delta as shown in Figure 2. 17. ．． 172, 173 may be used.

A switch open state period control element 8 (FIG. 1) is connected to the control input of switch 7. It is designed with a relay 18 having an input.

The normally closed contacts 19 of the relay 18 are parallel to the inductance coil 13. Connect to columns.

In another embodiment of this device (FIG. 3), the normally open connection of relay ]8 is Point 20 is connected in parallel to first capacitor 15 via third capacitor 21 .

The uneasy phase detection unit 9 (FIG. 1) includes a symmetrical voltage filter 22, whose input is connected to the appropriate first conductor of the first inductance coil 44, 4□, 43, and its d is connected to the amplifier 240 input via the narrowband filter 23. of amplifier 24 The output drives the manually controlled relay 18 of the switch 7.

This is a direct phase forward voltage filter tuned to the difference between the key frequency of switch 7 and the main frequency. It is used as a symmetrical voltage filter 22.

In another embodiment of the device, the switch 7 is tuned to the sum of the key frequency and the main frequency; A negative phase forward filter is used as this symmetrical voltage filter 22.

The symmetrical filter network 10 comprises first and second symmetrical filters 25 and 26. , their inputs are driven from the inputs of the receiving unit 1. First symmetrical filter 2 5 is tuned to the difference between the key frequency of the switch 7 and the main frequency, and a second symmetrical filter 26 is tuned to the sum of these frequencies. Narrowband filter network 1] is connected to each of the above frequencies. It consists of a first narrow band filter 27 and a second narrow band filter 28 which are tuned together. The power of the filter is connected to the first and second symmetrical filters 25 and 26 respectively, and the output is Connected to the input of comparison gate 29 (data input indicated by arrow).

These inputs of symmetrical filters 25 and 26 connect directly to the inputs of the receiver IC.

In this case, the symmetrical filter 25 performs a reverse order filtering action, and the filter 26 directly Performs phase sequential filter action.

The connection of the inputs of the symmetrical filters 25 and 26 to the inputs of the receiving unit 1 (FIG. 4) is The symmetrical filter 25 is provided by a two-phase rectifier switch 30, and the symmetrical filter 25 performs an antiphase forward filter operation. In this case, the filter 26 acts as a direct phase sequential filter.

The connection of the transmitting unit 2 to the power line 3 is direct, as shown in FIG.

In another embodiment (FIG. 5), the connection of the transmitter 2 to the power line 3 is through a first three-phase transformer 31. It is done more. The primary winding of this transformer is connected to the transmission line 3 phase, and the secondary winding is connected to the transmission line 3 phase. Connect to input of unit 2.

In the embodiment shown in FIG. 6, the receiving unit 1 is connected to the power transmission line 3 by a three-phase transformer 32. do. The primary winding of this transformer is connected to the transmission line 3 phase, and the 1.2 secondary winding is connected to the receiving unit. Connect to the input of port 1.

In this circuit configuration, the first and second symmetrical filters 25 and 26 are voltage filters. It is.

In the embodiment shown in FIG. 7, the receiving unit 1 has three current transformers 33,33 Connected to power transmission line 3 by 333 1 2' Continue. The primary windings of these current transformers are connected in series to each phase of the power transmission line 3, and the The first and second conductive wires are connected to the input of the receiving unit by being grounded.

In this embodiment, symmetrical filters 25 and 26 are current filters.

The symmetrical filter network 10 of the receiving unit 1 (FIG. 8) includes three third diodes. Do 34 34 343 and 1' 2' Consisting of three fourth diodes 35.35 353, 1 2' The cathodes of the third diodes 34□, 342, and 343 are connected to one common point and changed. It is connected to the first conducting wire of the primary winding of the voltage generator 36. The second conductor is the fourth diode 35 ,.

Connected to the common point of the anodes of 352 and 353, and the fourth diode 351, 35□, Common points between the cathode of 353 and the anode of the third diode 344, 342, and 343 is connected directly to the input of the receiving unit 1.

Narrowband filter network 11 has a third filter tuned to the key frequency of switch 7 (FIG. 1). A narrowband filter 37 has its input connected to the secondary winding of transformer 36.

Third diode 34. The cathodes of 342 and 343 are transformed through another resistor 38. It is connected to the first conductor of the primary winding of the device 36.

The cathode of the third diode 34.34 343 is 1 2.

The primary winding of the transformer 36 via the fourth capacitor 39 as in the embodiment of FIG. It may be connected to the first conductor of the line.

In Figure 1, there is no incomplete phase state in the three-phase power transmission shutoff, and the switch closed state period control The transmitting unit 20 function when the element is not used is as follows.

First, phase A has a higher potential than phase C during the time interval in question, so Diodes 5 and 6□ are conductive and diodes 52, 53, 61, and 62 are cut off. shall be Capacitor 5 is charged as shown in FIG. Thyristor〕2 is cut off until an ignition pulse is received from the thyristor ignition unit 14. thyristor When the ignition pulse from the ignition unit 14 enters the control electrode of the thyristor 12, the thyristor The star conducts and current flows through resistor 16 in the following path. Phase A - 1st inductor transformer coil 4, - first diode 5, - resistor 16, - thyristor 12, - second die The instantaneous value of the current of the ode 6 - the first inductance coil 43 - the phase C0 resistor 16 is as follows: It is as follows.

However, E　　　　　””　3　U　ffl/π The DC component of the 3-phase voltage, U is the 3-phase transmission line entrance , R is the ohmic resistance of this current path, and L is the amplitude of the line voltage of this current path. The inductance, t, is the opening period of the switch 7.

A forced switch circuit consisting of a first capacitor 5 and a second inductance coil 13 Due to the action of the thyristor 12, τ≦0.159To　　　　　　　　　After a time interval τ equal to (+4) do. However, τ is the conduction period of thyristor 12, and To is the key period of thyristor 2. It is de.

When the thyristor 12 is cut off, the first capacitor 5 is charged through the following path. phase A - first inductance coil 4 - first diode 51 - resistor 16 - second inductor [inductance coil] 3-second diode 63-first inductance coil 43-phase C. Charging of capacitor 5 is completed [After 7, thyristor ignition unit] from 4 The next ignition pulse enters the control electrode of thyristor 12 and the cycle repeats. It will be done.

By substituting equation (14) into equation (]3), the following equation is obtained.

is the maximum value of the current.

The signal currents in the first inductor coils 41 and 43 cause these coils to generate electromagnetic energy. Multiplying #, this energy when thyristor 12 is shut off is However, L″″L 4, + L 43i;! 1st inductance 1il 4 It is the sum of the inductance of 1 and 43.

After the thyristor 12 shuts off, this energy is transferred to a tuned circuit formed by causes vibration. Phase A - first inductance coil 41 - second capacitor 71 - First inductance coil 43 - Phase C (impedance of power supply phases A and B ignore). This circuit has a thyristor firing frequency f. i.e. [. 1/(2πF") (17). However, C-C171 C173/(C17, +C173) or C-C17/2.

C171"" C172-C173-C17 are the capacities of the respective second capacitors 17 It is.

Signal applied to each phase of a three-phase transmission line considering the effect of main voltage with main angular frequency Ω-2πF The current is as follows.

From equation (18), switch 7 operating at key frequency ω -2πfo is connected to this line. The frequency ω indicates currents in reverse phase A, B, C order (Fig. 10a). −Ω signal and direct Frequency ω indicating current in tangent order (Figure 10b). +Ω signal with frequency ω0±Ω2 It can be seen that two currents are applied.

Frequency ω. The signal current of ±Ω is applied directly and in reverse phase order between the phases of the three-phase transmission line 3 (Fig. 1). corresponding voltages are generated and these voltages enter the receiving unit 1. receiving unit The signal voltage from the output of 1 is a symmetrical filter designed with symmetrical filters 25 and 26. The filter 25 enters the circuit network 10, and the filter 25 performs a filtering action in reverse phase order. 6 performs a direct phase sequential filtering action. The output signals of filters 25 and 26 are the first narrow band A narrow band filter consisting of a band filter 27, a second narrow band filter 28 and a comparison gate 29 the router network 11; The first narrowband filter 27 is tuned to the frequency ω0−Ω. , the second narrow band filter 28 is tuned to the frequency ω0+Ω. narrow band filter 27 and The 28 passbands are chosen such that ΔF, ≦F.

In this way, from equation (18), if it is not in an incomplete phase state, the two frequencies ω±Ω A current is applied to the three-phase transmission line, and the effective value of the signal current is given by equation (18) as follows: become.

However, I (f - F) is the effective current in reverse phase order at frequency fOF. , I (f + F) is the frequency f. is the effective current of the direct phase sequence at +F .

The above is summarized in the table below.

Frequency f. -F fo+F Direct phase forward current 11 (fO+F) incomplete phase condition (phase A, rupture of B or C) under the frequency f. −F signal current], fo The +F signal current is shown in Figure 10d. In other words, directly at these frequencies and reverse) 1 order current has the effective current value shown in Table 2.

Thus, the unsafe phase condition divides the currents 11 (fo + F) and 12 (fo - F) into 2 minutes. 1 and which can be used to detect the occurrence of incomplete phase conditions in three-phase transmission lines. Let it flow. These new currents have a frequency f. −F current 11 (fo−F)/2 and Frequency f. The current of 10F is 1, (fo1F)/2.

Current 12 (fo-F) in incomplete phase state to half of 11 (fo + F) The reduction in interference insensitivity of the receiving unit 1, as well as its effect on conventional devices, cause damage. To restore the interference insensitivity in incomplete phase conditions, the received signal current must be The current must be increased by a factor of two, ie to the value in normal operating mode.

Table 2 Frequency f. −F fo+F direct phase forward current 1 (f’ − F)/2 11(f.+F)/2 can be done.

1, >): oτ/L　　　　　(20) From equation (20), half the current increase This can be done by doubling the closing period of switch 7. Siris During the period when the capacitor 12 is conductive, the first capacitor 15 and the second inductance coil 13 are is limited by the parameters of the forced switch circuit.

The reduction in the resonant frequency at which the forced switch circuit is tuned in an incomplete phase condition is due to the Increase the conduction period of Staco 2, thereby obtaining its new characteristic by Equation (20). A large current up to a fixed value is generated.

This device under incomplete phase conditions operates as follows.

Current in the transmitting unit 2 flows in two phases. Therefore, the frequency is f. ±F and the amplitude is Direct and anti-sequence currents are generated which are half of the normal ones. These symmetrical voltage components minute occurs at the input of the incomplete phase condition detection unit 9 (FIG. 1).

If the symmetrical voltage filter 22 is a direct phase sequential filter, then the narrowband filter 23 is f. - Must be tuned to F. The output of the narrowband filter 23 is sent to the amplifier 24. and its output signal is applied to the control input of switch 7.

This voltage controls the operation of relay 18. Due to the operation of this relay 18, the normally open When the contact 19 opens, the inductance of the second inductance coil] 3 is placed. Increase to desired value.

Nature of forced switch network consisting of capacitor 15 and inductance coil 13 The oscillation frequency is lowered, thereby extending the conduction period of the thyristor 12. signal current is increased to a specified value, improving interference insensitivity in signal reception under imperfect phase conditions. do good

By eliminating the incomplete phase condition in the three-phase transmission line, the input of the incomplete phase detection unit 9 can be reduced. Voltages U, (fo-F) and U2 (fo+F) disappear, and the relay 18 is about to de-energize. The normally closed contact 19 of is closed to short-circuit the second inductance coil 13. do. The circuit returns to its original state, i.e. the current applied to the transmission line 3 is Take values corresponding to normal operating conditions as shown in the table.

The increase in current under incomplete phase conditions is due to the action of relay 18 on normally open contacts 20. The first capacitor 15 (Fig. 3) connected in parallel is connected to the fourth capacitor 39 by opening. This can also be achieved by subsequently increasing the capacity.

This circuit configuration is used in conjunction with the apparatus of FIG.

In that case, the normally closed contacts 19 of relay 18 are not used.

The suppression of harmonic interference in the device of the present invention will be described next.

Adding signal current to two phases on the transmitter side and adding signal voltage or voltage from these two phases on the receiver side. The harmonic voltage of the main frequency is generated between the two phases from which the signal voltage was extracted. The interference line voltage will be .

The relationship between this interfering line voltage and the interfering voltage of the direct, anti- and zero-phase order symmetric components is The relationship is given by the following well-known formula:

θB−U1a2exp(jO) +U2aexp(j α)+Uoexp(j β) (21) Ul, U2. Uo is the modulus of the complex voltage in direct, inverse, and zero phase order, respectively. It is a rule.

In a symmetrical three-phase line, the N1-3n+1st order harmonics directly constitute a symmetrical system of phase forward voltages. , N2-3. It is known that the -1st harmonic constitutes a symmetrical system of negative phase forward voltage. Ru.

The No-3r first-order harmonic constitutes a zero-phase forward voltage system.

In the above, "l is an integer, that is. However, the subscripts 1, 2.O are Showing the direct, inverse and zero phase sequence harmonics respectively.

Direct, inverse and zero phase sequence harmonic components alternating along the frequency axis The modulus of the line voltage between phases A and B, , B and C1C and A for the harmonics in phase sequence. Each of the files constitutes the following:

By extremum analysis of equations (23)-(25), the following become that way.

However, U (wax) and Ul (win) are the maximum and minimum lines in direct phase order. is the on-voltage.

Equation (26) is also valid for negative phase forward line voltage.

However, U (+ax) and U, , (sin) are the maximum and minimum antiphase linear lines, respectively. is the on-voltage.

The difference between these maximum and minimum voltages is:

If k -4<'J, Δ -0, U, (may) - Ul (1n) - U %" It becomes J. k - becomes Δ2-0, and U (wax) - U (1n) - U There will be 21 guns.

Analyzing equations (28) and (29), we find that kl and 2 are the three-phase transmission for the harmonics in question. It can be seen that this shows the degree of asymmetry of the wire.

Equation (22) is applied in the case of symmetrical loads, which are practically rare in transmission lines, that is, k It is valid when -4~ and 2*~. Therefore, each harmonic component has a different level are characterized by direct, inverse and zero phase sequences. The maximum level is the high pitch shown in equation (22) Corresponding to the phase sequence with wave number, all other phase sequences are characterized by low levels. 1st The third harmonic corresponds to the direct phase sequence (N-13) and hence the direct, inverse and zero phase sequence. Its measurement at the same time as gives the following equation.

1θ l < l U (ta) t l < l U (13) 21 (30) However, U(13)0' U(13)] and U are respectively zero and U[pressure The occurrence is due to the asymmetric nature of actual three-phase power transmission lines.

As an example, Figure 11 shows 13th harmonic interference, where the upper level is directly The lower level indicates the interference voltage in reverse phase order.

Figure 12 shows interference due to the -7th harmonic, where the upper level is interference in reverse phase order. Voltage, the lower level indicates that of direct phase sequence.

Interference recording is performed using a symmetrical voltage filter 25 (Fig. 1) and a first narrow band with a passband of 40 Hz. This is taken by the filter 27. The output of the narrowband filter 27 is rectified. It was then used to drive a recorder. Direct phase sequential filter of reverse phase sequential filter Any two phases at the input of filter 25 were alternated to convert it to a

A comparison of the interference voltage of the line voltage with that of the symmetrical element reveals the following: It became a thing.

According to equation (26), the direct phase-sequential harmonics are It is characterized by U (wax) - Ur (k + 1) (3t). Formula (22 ) is receiving a signal containing direct phase-sequence harmonics, an anti-phase order filter is receiving Then, the interference voltage of the output of this negative phase forward filter is U2, that is, U2〈put)−U o(32) Configure. The ratio of equation (31) to equation (32) is. According to formula (27), Reverse) 1st harmonic is characterized by U (wax) - Dr (k + 1) (34) shall be. When a signal containing out-of-phase harmonics in Equation (22) is received, a direct phase-sequence filter is applied. The interference voltage is Ul, which is U (out) = U 1 (35) becomes. The ratio of equation (34) to equation (35) is as follows.

Thus, the maximum interference voltage in the line voltage is equal to the symmetric component interference voltage C(k+1) (−k for direct phase-sequential harmonics, −k for anti-phase sequential harmonics) ).

■ Quantitative evaluation of the value of k based on the results of measurements over many years shows the interference of direct and antiphase classes. It was obtained by statistical probability analysis of the relationship between voltages. By processing the statistical values, the expected value There was the following relationship between N and the odd harmonic number N.

k-1,00/(1,5+0.372N) (37) Equations (33), (36) and (37), it follows that the signal reception by the symmetrical filters 25 and 26 (Fig. 1) is It is shown that it provides a significant advantage in interference suppression of harmonic components.

The signal receiving frequency is for an anti-phase type filter, where F is the main frequency, P-1, 2; 3. ...f2 is the tuning frequency of the narrowband filter (Fig. 1), for the direct phase order filter. Teha However, fl is selected to satisfy the tuning frequency of narrowband filter 28 (FIG. 1).

The key frequency of switch 7 (Fig. 1) is limited to.

Thus, equations (38)-(40) are in direct and antiphase class with the key frequency of switch 7. allows the determination of the resonant frequency of a narrowband filter loaded with a symmetrical filter. Ru.

FIG. 2 shows the cathode of the second diode 6 and the corresponding anode of the first diode 5. Three second capacitors (1, 7, 172,, 173 ) shows capacitive coupling. In this configuration, capacitor 17 . 172,17 The value of 3 is half of the star-wired capacitor 7 (Figure 1) at full line voltage. It is one third of the value at line voltage.

This circuit configuration is used in conjunction with the device of Figure 1, in which case it is assumed to be a star configuration. Capacitors 171, 172 and 173 are not used.

The device shown in Figure 4 is a three-phase power transmission line between the transmitting unit 2 and the receiving unit 1. enables the detection of incomplete phase states. Table 2 shows the frequency f. -F direct phase forward current I (f - F)/2 and frequency f. 10F negative sequence forward current O ■. Transmission on transmission line in incomplete phase condition when (fo+F)/2 both exist The signal current value generated by unit 2 is shown.

In order to receive these signal currents, any two phases in the receiving unit 11; This can be done by the phase commutator switch 30. child In this case, the first symmetrical filter 25 is a direct phase sequential filter, and the filter 26 is a three-phase transmission line filter. anti-phase type filter to pass each voltage generated in the transmission line in an incomplete phase state. and (7).

This circuit configuration is used in conjunction with the apparatus of FIG.

In some cases, for example, a balance capacitor or When the signal voltage is received, the signal voltage is shunted by these capacitors to making it impossible to do so and instead making it possible to receive a signal current. times for signal current reception The road configuration is shown in Figure 7. In this figure, the signal current flowing through each phase of transmission line 3 varies. Flow vessel 33.

332.333 secondary winding and then the current flow in this case The signal is sent to a symmetrical filter 25° 26 which is a router. Other parts of receiving unit 1 are It functions in the same way as described above for signal voltage reception.

This circuit configuration is used in connection with the apparatus of FIG. 1, but the second three-phase transformer 32 is removed.

Third diode 340.34□, 343 and fourth diode 35.35°, 353 The three-phase rectifier bridge designed in (Fig. 8) has a symmetrical filter network 10 and and acts as a narrowband filter network 11. These diodes have a frequency f. + The first diode 50, 5□, 53 and the second diode in the transmitting unit 1 which generates the H signal Because it turns on and off in synchronization with the diodes 62, 62, and 63, The key frequency fo, which is the operating frequency of switch 7, is routed to the output of this rectifier bridge. Revenge. The resistor 38 (Fig. 8) and the fourth capacitor 39 (Fig. 9) transformer 36 (Fig. 8.9) 3. Eliminate direct ohmic connection of narrowband filter 37. The third narrow band filter 37 is actually It constitutes a qualitatively narrow band filter network. The circuit configuration in Figure 8.9 shows that the signal frequency is Frequency ranges or varying noise that lie between harmonics and give high levels of harmonic interference The frequency at which the harmonic interference level is proportional to the frequency (10KHz-12KHz) Suitable for receiving signals when within range.

The circuit configuration of Figure 8.9 may be used in conjunction with the apparatus of Figure 1, but with a first symmetrical filter. filter 25, second symmetrical filter 26, first narrowband filter 27, second narrowband filter 28 and comparison gate 29 are eliminated.

industrial applications The present invention provides power substations from a controllable station on the low voltage side of a power transmission line. It is most suitable for transmitting information to the power supply board of the system.

The distance between these positions is 1 and the operating frequency corresponding to the wavelength is that this distance is 4 minutes of the operating wavelength. is less than 1.

In this case, the three-phase transmission line, which is a distributed constant line, is treated as a line with lumped constants. The wave processing that occurs during signal transmission can be ignored.

Controllable stations are line loads, substations, and segment nodes in a three-phase AC transmission network. It can be an automatic standby device.

The above principle for creating a communication channel through a three-phase power line is based on a controllable speed to provide two-way communication and remote control between the station and the power supply station. It can be used effectively to transmit commands from the power supply station to the control station. Ru.

Procedural amendment (formality) 1 Display of incident PCT/SU　88100249 3 Person making the amendment Relationship to the incident Patent applicant Shipping date: April 16, 1991 6 Target of correction −International search report r　　　　□□″″〜″″″B1002″9 pieces

Claims (1)

[Claims] 1. a receiver unit (1) and a transmitter unit with an input connected to the power line (3); This transmitter unit (2) has three first inductance coils. (41, 42, 43), three first diodes (51, 52, 53) and three first diodes (51, 52, 53), 2 diodes (61, 62, 63) and a switch (7), the first inductor The first conductor of the tank coil (41, 42, 43) is connected to the input of the transmitter unit (2). The second conductor of the first inductance coil (41, 42, 43) is connected to the Connected to the anode of the first diode (51, 52, 53), whose cathode is one and the first input of the switch (7), and its second input. The force is connected to the common point of the interconnected anodes of the diodes (61, 62, 63). Subsequently, the respective cathodes of the second diodes are connected to the respective inputs of the transmitter unit (2). In addition, the switch (7) has a switch closure period control. control element (8) and control input, and incomplete phase state detection unit (9). and that said receiving unit (1) comprises a symmetrical filter network (1 0) and a narrowband filter circuit (11). A device for transmitting signals. 2. the transmitter unit of the cathode of the second diode (61, 62, 63); Electrical coupling to the input of (2) is the first inductance coil (41, 42, 43) The cathodes of the second diodes (61, 62, 63) are aligned with each other. and the anode of said first diode (51, 52, 53) are connected to one common point, and the first inductance coil is connected between the common point. (41, 42, 43) are given capacitive coupling to form an oscillation circuit. and that the switch (7) is connected to the thyristor (12) and the second inductor. coil (13), thyristor ignition unit (14) and first capacitor (1 5) and a resistor (16), and the input of the first switch (7) connects the resistor (16). The anode of the thyristor (12) and the first brake of the first capacitor (15) are connected through the the second plate is connected to the first conductor of the second inductance coil (13). The second conductor connects to the cathode of the thyristor (12) and the switch (7). ), and the thyristor ignition unit (14) is connected to the second input of the thyristor (1 Claim 1 characterized in that it is connected between the control electrode of 2) and its cathode. The device described. 3. The cathode of the second diode (61, 62, 63) and the first diode (5 The capacitive coupling between the common points of the anodes of Nos. 1, 52, and 53) is the result of three star-connected anodes. characterized by being provided by a second capacitor (171, 172, 173) 3. A device according to claim 2. 4. the cathode of the second diode (61, 62, 63) and the first diode The capacitive coupling of the common point question of the anodes of (51, 52, 53) is Δ connection. is provided by the second capacitor (171, 172, 173) of 3. The device according to claim 2. 5. Said switch closure period control element (8) consists of a relay (18) whose input The device according to claim 1, characterized in that said switch (7) is connected to a control input of said switch (7). Place. 6. A normally closed contact (18) of said relay (18) connects said second inductance. 6. Device according to claim 5, characterized in that it is in parallel with a part of the coil (13). 7. A normally open contact (20) of said relay (18) connects a third capacitor (2 1) is connected in parallel to the first capacitor (15) via the capacitor (15). The device according to item 5. 8. The unsafe phase detection unit (9) consists of a symmetrical voltage filter (22), Its input is connected to the first conductor of the first inductance coil (41, 42, 43). Its output is then connected to the input of an amplifier (24) via a narrowband filter (23). and the output of this amplifier is connected to the control input of the switch (7). 2. The apparatus of claim 1. 9. The symmetrical voltage filter (22) has a key frequency and a main frequency of the switch (7). 9. The device according to claim 8, characterized in that it is a direct phase sequential filter tuned to numerical differences. . 10. The symmetrical voltage filter (22) is configured to match the key frequency and main frequency of the switch (7). 9. The device according to claim 8, wherein the device is an inverted phase forward filter tuned to the sum of wave numbers. . 11. The symmetric filter network (10) has a first symmetric filter (25) and a second symmetric filter network (10). consisting of filters (26) whose inputs are connected to the inputs of said receiver unit (1). The first symmetrical filter (25) is connected to the key frequency of the switch (7) and the main frequency. The second symmetrical filter (26) is tuned to the difference in frequency, and the second symmetrical filter (26) is tuned to the sum of the key frequency and the main frequency. and said narrowband filter network (11) is tuned to said difference and sum frequencies respectively. It consists of first and second narrowband filters (27) and (28) that forces are connected to the outputs of said first and second symmetrical filters (25), (26), respectively; Claim 1, characterized in that their outputs are connected to a comparator gate (29). equipment. 12. The inputs of the first and second symmetrical filters (25) and (26) are connected to the receiver. The first symmetrical filter (25) is connected directly to the input of the unit (1), and the first symmetrical filter (25) is in reverse phase order. The second symmetrical filter (26) performs a direct phase-sequence filtering action. 12. The device according to claim 11, characterized in that it performs. 13. the receiver unit of the first and second symmetrical filters (25), (26); Connection to the input of the first gate (1) is provided by a two-phase rectifier switch (30), A symmetrical filter (25) performs a direct phase-sequence filtering action, and the second symmetrical filter The device according to claim 11, characterized in that (26) performs a filtering action in reverse phase order. . 14. The connection of the transmitter unit (2) to the power line (3) is a direct connection. 2. A device according to claim 1, characterized in that: 15. The connection of the transmitter unit (2) to the power transmission line is through the 23rd phase transformer (31 ), whose primary winding is connected to the phase of the above transmission line (3), and whose secondary winding is The device according to claim 1, characterized in that it is connected to an input of the transmitter unit (2). Place. 16. The connection of the receiver unit (1) to the power line (3) is a direct connection. 2. A device according to claim 1, characterized in that: 17. The electrical coupling of the receiver unit (1) to the power transmission line (3) provided by a phase transformer (32), the primary winding of which is connected to the phase of said transmission line (3) and the secondary winding is connected to the input of the receiver unit (1). The device according to claim 1. 18. The first and second symmetrical filters (25) and (26) are voltage filters. Claim 11 related to claim 16 or the device according to claim 11, characterized in that: Place. 19. The electrical coupling of the receiver unit (1) to the power transmission line (3) consists of three variables. currents (331, 332, 333), whose primary windings are These current transformers (331, 332, 333) are connected in series to each phase of line (3). The first conductor is grounded, and the second conductor is connected to the input of the receiver unit (1), respectively. The device according to claim 1, characterized in that: 20. The first and second symmetrical filters (25) and (26) are current filters. 12. The apparatus according to claim 11. 21. The symmetrical filter network (10) includes three third diodes (341, 34). 2,343), three fourth diodes (351,352,353), and a transformer (3 6), and the cathode of the third diode (341, 342, 343) is Connected to one common point and connected to the first conductor of the primary winding of the transformer (36). The second conducting wire is connected to the fourth diode (351, 352, 353). connected to the common point of the anodes, and the fourth diode (351, 352, 353 ), the common point of the interconnected cathodes of the fourth diode (351, 352, 3 53) and the third diode (341, 3) The interconnected anodes of 42, 343) are connected directly to the input of the receiver unit (1). the narrowband filter network (11) is connected to a third narrowband filter (37); the input of which is connected to the secondary winding of said transformer (36), and whose input is connected to the secondary winding of said transformer (36); The filter (37) is characterized in that it is tuned to the key frequency of the switch (7). The device according to claim 1 in relation to claim 16 or claim 1 in relation to claim 17 Place. 22. Before the common point of the cathodes of the third diodes (341, 342, 343) Electrical coupling of the primary winding of the transformer (36) to the first conductor is provided by a resistor (38). 22. A device according to claim 21, characterized in that it is provided with: 23. Before the common point of the cathodes of the third diodes (341, 342, 343) Electrical coupling to the first conductor of the primary winding of the transformer (36) is provided by a fourth capacitor (39). 22. Device according to claim 21, characterized in that it is given by: ).