SU796892A1 - Transmitting device for remote control of cathode protection system of pipelines - Google Patents

Description

(54) TRANSMISSION DEVICE FOR CATHODE CONTROL CATHODE PROTECTION OF PIPELINES

one

The invention relates to a technique for remote monitoring of cathode protection installations for pipelines and can be used in the oil and gas industry.

Telecontrol devices for cathodic protection of pipelines are known, in which a pipeline communication channel or special cable and air lines 1 are used to transmit information.

However, the need to build communication lines, as well as the need to use signal relay, significantly reduces the economic performance of the system.

The closest technical solution to the present invention is a transmitter for telecontrol of cathodic protection stations for pipelines containing a power supply unit whose input is connected to an alternating current network, the first outputs are connected to the power supply terminals of the unit, the second outputs are connected to the first impulse driver, and the third the output is connected to the first plate of the storage capacitor and to the first output of the LC circuit, the second output of which is through the choke

connected to the thyristor anode, the thyristor cathode is connected to the second plate of the storage capacitor and to the second output of the power supply unit; the control electrode of the thyristor is connected to the output of the pulse shaper, the cathodic protection station, the first input of which is connected to one of the phases of the AC network, the positive output of the station The cathodic protection is connected to the grounding circuit, and the negative output of the cathodic protection station is connected to pipeline 2j.

A disadvantage of the known device is the small amount of information transmitted.

The purpose of the invention is to increase the information content of the device.

The goal is achieved by

0 that a barrier choke, an attachment capacitor, an attachment resistor, a transistor switch and an OR element and resistors, the OR element inputs are connected to the device

5 through the resistors with the plus output of the cathodic protection station, the output of the element OR is connected to the base of the transistor switch, the emitter of which is connected to the output of the multivibrator, and 0 the collector is connected to the second driver of the pulse shaper, the connection resistor is connected in parallel to the secondary winding of the LC circuit, the first output of which connected through a coupling capacitor to one phase of the AC network, the other phase of which is connected to the second output of the secondary winding of the LC circuit and through the barrier choke to the second one do cathodic protection station.

The goal is also achieved by introducing resistors and relays into the device, the first resistor is connected in series to the negative output circuit of the cathodic protection station, a relay coil is connected in parallel to the first resistor, the output of the multivibrator is connected to the second input of the ramp through the disconnecting relay pulses.

- FIG. 1, 2 and 3 shows the layout of the device.

The device contains a cathodic protection station 1, a transmitting pulse generator 2, a power, a transformer 3, a high-voltage line 4, a sectioning switch 5, an induction pulse sensor b, a compensation filter 7, pulse amplifiers 8, elements AND 9, a pulse shaper 10, a pulse distributor 11, output elements 12, multivibrator 13, relay 14, resistor 15, thyristor 16, pulse shaper 17, storage capacitor 18, LC circuit 19 (shock excitation), barrier choke 20, coupling capacitor 21, resis connection torus 22, transistor switch23 ground circuit 24, element OR 25 whose power supply unit 26 is connected via a resistor to additional ground 24 and the output of logic element OR 25. The inputs of logic element OR 25 are connected to the output terminal plus cathodic protection station 1.

The device works as follows.

A 6–10 kV high-voltage line (4) passes along the pipeline route to power the cathodic protection station 1, as well as a communication channel (Fig. 1). In normal operation of the cathode protection of the pipeline, the contacts of the relay 14 are open. In this case, the pulse generators 2 (Fig. 2) of all transmitting units operate continuously, and the signals follow with a network frequency of 50 Hz. Phase pulse and frequency methods are used together to seal the channel. A working impulse in a pulsed generator is formed when a storage capacitor 18 is discharged onto the circuit 19 of shock excitation. The pulse filling frequency does not exceed 50 kHz. The formation of phase characteristics is provided by powering the pulse generators with a voltage of a 3-phase network having a different phase shift. In line with this, all transmitting pulse generators are combined into groups of 6 each with the same pulse filling frequency. Thus, when using one frequency, 6 transmission channels are formed, two frequencies — 12 transmission channels, etc. In FIG. 1 block scheme uses 2 frequencies and the number of transmission channels is 12.

When the magnitude of the polarizing current disappears or decreases, the contacts of the current relay 14 close and the multivibrator 13 manipulates the oscillations of the pulse generator 1 with a pause duration equal to 1 s (the pulse diagram of the transmitting pulse generator is shown in Fig. 1). To monitor the state of cathodic protection stations when more than one is installed at one point (Fig. 3), the pulse generator is manipulated through a transistor switch 23. In normal mode, when all the cathodic protection stations are working, transistor switch 23 is locked and the generator manipulation circuit is off . When the current at the output of the cathode station disappears, a positive signal 9 is not fed to the input of the OR 25 logic element, and the key 23 is opened by connecting the input of the pulse generator to the output of the self-oscillating multivibrator. Essentially, the transistor switch 23 and the logic element OR 25, together with the additional ground 24, perform the functions of a remote signaling sensor. The number of inputs of the logical element OR 25 is equal to the number of monitored cathodic protection stations. In the channel control mode, each transmitting pulse generator generates pulses, followed continuously with a frequency of 50 Hz, which, successively passing through the power transformer 3, high-voltage line 4, sectioning switch 5, monitor their healthy state. In the receiving device (Fig. 1), the pulse sensor 6 and the compensation filter 7 are separated by pulses at the filling frequency f and f and fed to the corresponding pulse amplifiers 8. Pulse phase selection through the transmission channels is carried out using pulse distributor 11 and logical elements And 9. The shaper clock pulses 10 generates clock pulses, the next with a frequency of 50 Hz, synchronously with the network. Information on the dispatcher's panel is provided by the output elements 12. The compensation filter 7, in addition to the functions of the pulse selection frequency, compensates for the impulse noise and the reception of pulses with different filling frequencies. In addition to the working windings, the pulse sensor contains one compensation winding. Since the pulsed signals propagate along the three wires of the line /, to improve the reception conditions, the pulse sensor is made in three sections. Each section is located under the corresponding bushing of the switchgear, observing the insulation distance. The pulse sensor section consists of the same number of coils included according to. The coil sections of the pulse sensor of the same name have the same natural resonant frequencies equal to the frequency of filling their pulses.

Transmitting impulse generators are connected to the high-voltage line through a power transformer using a capacitor 21. Resistor 22 serves to limit the voltage of 50 Hz on the LC-CO 19 circuit of the shock excitation. The barrier choke 20 serves to increase the input resistance of the cathode signal station at the pulse filling frequency.

The proposed device, in addition to the telecontrol of cathodic protection stations, allows simultaneously KOHTpoJtepo position of automatic sectioning switches and the state of the high-voltage supply line.

Claims (2)

1. Transmitter for telecontrol of cathode protection of pipelines, the power supply unit whose input is connected to the AC network, the first outputs are connected to the power terminals of the multivibrator, the second outputs are connected to the first inputs of the pulse conditioner, and the third output is connected to the first capacitor capacitor plate and with the first output of the LC circuit, the second output of which is connected via a choke to the thyristor anode, the cathode .tiristor connected to the second obklad. With the storage capacitor and with the second output of the power supply unit, the control electrode of the thyristor is connected to the output of the pulse former, the cathodic protection station, the first input of which is connected to one of the phases of the AC network, the positive output of the cathodic protection station is connected to the grounding circuit, and the negative output of the cathodic protection station About connected to the pipeline, characterized in that, in order to increase the informativeness of the device, a protective choke, a coupling capacitor, 5 connection resistor, transistor switch, OR element and resistors, OR element inputs are connected via resistors to the positive output of the cathodic protection station, OR element output 0 is connected to the base of the transistor switch, the emitter of which is connected to the output of the multivibrator, and the collector is connected to the second input of the pulse shaper, the connection resistor is connected in parallel to the secondary winding of the LC circuit, the first output of which is connected to the alternator. current, another phase of which jj is connected to the second. the output of the secondary winding of the LC circuit and through the barrier dross. n - to the second entrance of the cathodic protection station. 2. The device according to claim 1, characterized in that resistors and relays are introduced into it, the first resistor is connected in series to the negative output circuit of the cathodic protection station, parallel to the first 0 the resistor is connected to the relay coil, the output of the multivibrator disconnecting contact of the relay and a series-connected resistor connected to the second input of the driver 5 pulses. Sources of information taken into account in the examination 1. USSR author's certificate  410438, cl. G 08 C 19 / 12,01.12.71. 2. Author's certificate of the USSR 451118, cl. G 08 C 19 / 12,14.06.71 (prototype). / II15 ; CH-R - | H I I -SS rr : fr y №Q - r-LT- rV I, I, I, I, I, I, I, I, I, I, I I I I I I 2g fshch.2 Fig.Z