CN102495298B - Method for realizing line phase check by using programmable logic controller (PLC) - Google Patents

Abstract

The invention belongs to the technical field of three-phase power transmission line construction in a power system, and in particular relates to a method for realizing line phase difference verification by using PLC. In the present invention, the two ends of the three-phase transmission line are respectively connected to the PLC phase difference checker, the action of the relay is measured, and the measurement results are transmitted to the PLC phase checker, and then the PLC phase checker performs calculations, and finally Light the measurement result display light plate 1 on the PLC phase difference calibrator through the contacts output by the PLC to display the measurement result. The invention adopts the DC working voltage mode, overcomes the problem of the AC induced voltage of the three-phase power transmission line in the complex electromagnetic environment, and realizes the logic relationship of phase distinction through the logic matrix of the PLC programmable controller. It can greatly simplify the wiring workload of the secondary circuit, the PLC programming is simple, and it is easy to manufacture. The invention can realize the function of rapid phase difference verification, eliminate the phenomenon of wrong phase, and significantly improve the working efficiency.

Description

The Method of Using PLC to Realize the Differential Checking of Lines

technical field

The invention belongs to the technical field of construction of three-phase transmission lines in electric power systems, and in particular relates to a method for using PLC to realize phase-specific verification of lines.

Background technique

In the construction of an overhead transmission line in the power system, because the three-phase transmission line needs to change phases continuously during the tower erection process in the air, it is difficult to distinguish the corresponding relationship between the three phases at both ends of the line, which can easily cause power transmission. When the phase sequence error phenomenon is found, it will directly cause the "wrong phase" phenomenon between one end and the other end of the three phases caused by continuous commutation.

Therefore, it is very necessary how to carry out the correct nuclear phase work before power transmission to ensure that the power transmission is successful once. Different from ordinary calibration of a section of uncharged wire with the ohm gear of a multimeter, a section of overhead transmission line often needs to go through a distance of tens to hundreds of kilometers. During this period, it has undergone numerous phase changes, and the electromagnetic environment of each phase wire is complex. , A high voltage will be induced between the phase wires and between each phase and the ground, and the ordinary conduction method can no longer meet the needs of phase-specific calibration.

Contents of the invention

The present invention aims at the problems existing in the above-mentioned prior art, and provides a method for realizing phase difference verification of lines by using PLC, the purpose of which is to realize the fast phase verification function, prevent the occurrence of false images, and significantly improve work efficiency.

The present invention realizes the technical scheme of invention as follows:

The method of using PLC to realize the phase difference verification of the line, firstly connect the three terminals at one end of the three-phase transmission line to the three terminals on the PLC phase difference checker;

Then connect the three wiring terminals at the other end of the three transmission lines to the other three wiring terminals of another PLC phase difference checker, and the PLC phase checker at this end will automatically transmit according to the connected three-phase power transmission line. The condition of the three wiring terminals of the line makes the measurement relay act, the contact of the measurement relay is input to the PLC input terminal of the "PLC phase difference checker", and the PLC performs a logic output on the input of the measurement relay input to the contact 3 of the PLC. , and finally through the PLC output contact to light up the measurement result display light plate 1 on the PLC phase difference calibrator to display the measurement result.

Described PLC phase difference calibrator is to be provided with voltage generator, measurement relay, PLC programmable controller 2 and measurement result display light plate 1 several parts in housing; When carrying out phase difference measurement to three-phase transmission line , connect the voltage generator and the measuring relay together through the transmission line.

The measuring relays J1, J2 and J3 in the PLC phase difference calibrator are each composed of six sub-relays:

J1 consists of six relays connected in parallel: J1-1, J1-2, J1-3, J1-4, J1-5, J1-6;

J2 consists of six relays connected in parallel: J2-1, J2-2, J2-3, J2-4, J2-5, J2-6;

J3 consists of six relays connected in parallel: J3-1, J3-2, J3-3, J3-4, J3-5, J3-6;

The action voltage of J1-1, J 2-1, J3-1 is set to about 50 volts;

The operating voltage of J1-2, J 2-2, J3-2 is set to about 100 volts;

The operating voltage of J1-3, J 2-3, J3-3 is set to about 150 volts;

The operating voltage of J1-4, J 2-4 and J3-4 is set to about -50 volts;

The action voltage of J1-5, J 2-5, J3-5 is set to about -100 volts;

The operating voltage of J1-6, J 2-6 and J3-6 is set to about -150 volts;

Input the contacts of the above 18 relays as switch inputs to the digital input terminals of the programmable controller in the following order:

The order from lowest to highest is: J1-1, J1-2, J1-3, J1-4, J1-5, J1-6, J2-1, J2-2, J2-3, J2-4, J2-5, J2-6, J3-1, J3-2, J3-3, J4-4, J5-5, J6-6.

The voltage generator adopts the mode of working voltage of DC power supply, and the DC power supply can be composed of dry batteries connected in series and parallel, or can be obtained from 220V AC through transformer, rectification, filtering and voltage stabilization circuit. the

The 80V and 100V operating voltages used in the DC power supply can also be changed to other operating voltages. At the same time, the operating voltage settings of the 18 fast relays corresponding to the relays J1, J2, and J3 should also be adjusted according to the operating voltage of the DC power supply. corresponding changes.

Advantageous effect of the present invention is:

In the present invention, because the described PLC phase difference checker adopts the mode of DC working voltage, the AC induced voltage problem of the three-phase transmission line under the complex electromagnetic environment is overcome, and the logical relationship of phase difference is through the PLC programmable controller implementation of the logic matrix. Based on the above DC working circuit, the logic matrix of the PLC programmable controller can greatly simplify the wiring workload of the secondary circuit, and the PLC programming is simple and easy to manufacture. The three-phase transmission line is added with the interphase DC power supply voltage instead of the ground AC voltage, in order to eliminate the common mode interference and the electromagnetic induction interference of the space electromagnetic field. The DC relay adopts the voltage type instead of the current type because the power of the DC power supply can be made very small in order to reduce the size and weight of the power supply. The present invention can realize the function of rapid phase difference verification, prevent the occurrence of false images, and can significantly improve the working efficiency.

Description of drawings

Fig. 1 is a schematic circuit diagram of the present invention;

Fig. 2 is the external structure schematic diagram of PLC phase difference checker among the present invention;

Fig. 3 is the schematic diagram of the internal voltage generator of the PLC phase difference checker in the present invention;

Fig. 4 is the internal relay schematic diagram of the PLC phase difference checker among the present invention;

Fig. 5 is the schematic diagram of the circuit composition of the relays J1, J2, J3 in the PLC phase difference checker among the present invention;

Fig. 6 is a schematic diagram of PLC input and output results in the present invention.

In the figure: the measurement result shows the optical plate 1, the PLC programmable controller 2, and the contact 3 of the measurement relay input to the PLC.

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

Detailed ways

Example 1:

The invention is a method for realizing line phase difference verification by using PLC, using DC power supply for signal transmission, using relay action and contact output to programmable controller PLC to realize logic function, and achieving the purpose of distinguishing phase sequence indication results.

As shown in Figure 1-6, the method of using PLC to realize the phase difference verification of lines is as follows:

First, connect the three terminals at one end of the three-phase transmission line to the three terminals on the PLC phase difference checker;

Then connect the three wiring terminals at the other end of the three-phase transmission line to the three wiring terminals of another PLC phase difference checker, and the PLC phase checker at this end will automatically follow the connected three-phase transmission line. According to the three connection terminals, the measurement relay is activated, the contact of the measurement relay is input to the PLC programmable controller 2 input terminal of the "PLC phase difference checker", and the PLC checks the connection of the contact 3 of the measurement relay input to the PLC. Logic output, and finally through the PLC output contact to light the measurement result display light plate 1 on the PLC phase difference calibrator to display the measurement result.

PLC is a part of the phase difference calibrator: the phase difference calibrator is composed of a voltage generator, a measurement relay, and a measurement result display light plate 1. There is no circuit connection between the voltage generator and the measurement relay in a normal state. Only when conducting phase-specific measurements on three-phase transmission lines, the two are connected together through the transmission line itself.

The measuring relays J1, J2 and J3 in the PLC phase difference calibrator are each composed of six sub-relays:

J1 consists of six relays connected in parallel: J1-1, J1-2, J1-3, J1-4, J1-5, J1-6,

J2 consists of six relays connected in parallel: J2-1, J2-2, J2-3, J2-4, J2-5, J2-6,

J3 consists of six relays connected in parallel: J3-1, J3-2, J3-3, J3-4, J3-5, J3-6.

The operating voltage of J1-1, J2-1, J3-1 is set to about 50 volts,

The action voltage of J1-2, J 2-2, J3-2 is set to about 100 volts,

The action voltage of J1-3, J 2-3, J3-3 is set to about 150 volts,

The operating voltage of J1-4, J 2-4, J3-4 is set to about -50 volts,

The operating voltage of J1-5, J 2-5, J3-5 is set to about -100 volts,

The action voltage of J1-6, J 2-6, J3-6 is set to about -150 volts.

Input the contacts of the above 18 relays as switch inputs to the digital input terminals of the programmable controller in the following order:

The order from lowest to highest is: J1-1, J1-2, J1-3, J1-4, J1-5, J1-6, J2-1, J2-2, J2-3, J2-4, J2-5, J2-6, J3-1, J3-2, J3-3, J4-4, J5-5, J6-6

(1) When it is 111000 011000 000001, it is ABC phase sequence, and the detection result is: the one connected to the "1" terminal is the A phase, the one connected to the "2" terminal is the B phase, and the one connected to the "3" terminal is C Mutually.

(2) When it is 001000 110000 000111, it is the ACB phase sequence, and the detection result is: the phase connected to the "1" terminal is A phase, the phase connected to the "2" terminal is C phase, and the phase connected to the "3" terminal is B Mutually.

(3) When it is 000001 000111 000011, it is BCA phase sequence, and the detection result is: the one connected to the "1" terminal is B phase, the one connected to "2" terminal is C phase, and the one connected to "3" terminal is A phase Mutually.

(4) When it is 011000 111000 001000, it is the BAC phase sequence, and the detection result is: the phase connected to the "1" terminal is B phase, the phase connected to the "2" terminal is A phase, and the phase connected to the "3" terminal is C Mutually.

(5) When it is 000011 001000 111000, it is the CAB phase sequence, and the detection result is: the phase connected to the "1" terminal is phase C, the phase connected to the "2" terminal is phase A, and the phase connected to the "3" terminal is B Mutually.

(6) When it is 000111 000001 011000, it is the CBA phase sequence, and the detection result is: the one connected to the "1" terminal is the C phase, the one connected to the "2" terminal is the B phase, and the one connected to the "3" terminal is A Mutually.

The action values of relays J 1, J 2, J 3, J 4, J 5, and J 6 are respectively set as when +50V, +100V, +150V, -150V, -50V, -100V, -150V are added to both ends of MN Action, each relay can output a pair of normally open contacts, the PLC programmable controller program edits to form a logical relationship, output a result and connect it to the display light plate circuit to light up the corresponding display light plate light, display measurement results.

The PLC phase difference checker adopts the mode of DC power supply working voltage. The working voltage of 80V and 100V used by the DC power supply can also be changed to other working voltages. At the same time, the operating voltage setting value of the 18 fast relays corresponding to the relays J1, J2, and J3 should also be changed accordingly with the working voltage of the DC power supply. .

In the actual implementation of the present invention, 1 ^/ , 2 ^/ , 3 ^/ are connected with terminals 1, 2, and 3 before entering the measurement circuit at the back and go through 50HZ power frequency filtering, which is not shown in the figure. The specific verification operation method and working process are as follows:

In the case where the phase difference of the three-phase terminals of the transmission line on side A is known, how to determine the corresponding phase relationship between the three unknown terminals on side B at the other end of the transmission line and side A is as follows:

1. The staff on the A side of the three-phase transmission line connect the A, B, and C terminals of a PLC phase difference checker to the A, B, and C terminals of the three-phase transmission line that have been determined.

2. The staff on the B side of the three-phase transmission line first mark the three terminals of the three-phase transmission line on the B side as terminals 1 ^/ , 2 ^/ , 3 ^/ , and then mark the 1, , Terminals 2 and 3 are respectively connected to terminals 1 ^/ , 2 ^/ , 3 ^/ , and the PLC phase difference checker on the second side will automatically display ABC and ACB in the order of terminals 1 ^/ , 2 ^/ , 3 ^/ . , BCA, BAC, CAB, CBA test results of one of the six relationships: if the CBA phase sequence indicator light shows that the light plate is lit, it means: 1 ^/ connected to the "1" terminal is C phase, and " The 2 ^/ connected to the 2" terminal is the A phase, and the 3 ^/ connected to the "3" terminal is the B phase.

3. This kind of test must have a PLC phase difference checker on both sides of the three-phase transmission line, and the staff on both sides communicate and cooperate by telephone. The reason why the voltage generator, relay and measurement result display part of the PLC phase difference calibrator are combined on one device is to maintain the integrity of the device and prevent part loss. The PLC phase difference checker uses voltage relays instead of current relays because the power provided by the power supply at the signal generating end can be minimized, so as to reduce the volume and weight of the PLC phase difference checker.

Claims (2)

1. The method of using PLC to realize the line phase difference verification is characterized by: First, connect the three terminals at one end of the three-phase transmission line to the three terminals on the PLC phase difference checker; Then connect the three connection terminals at the other end of the three-phase transmission line to another group of three connection terminals of another PLC phase difference checker, and the PLC phase difference checker at this end will automatically follow the three connected terminals. The condition of the three terminals of the phase transmission line makes the measurement relay act, the contact of the measurement relay is input to the PLC input terminal of the "PLC phase difference checker", and the input of the measurement relay to the input of the PLC is connected to the contact (3) of the PLC The logic output is carried out, and finally the measurement result display light plate (1) on the PLC phase difference calibrator is illuminated through the contact of the PLC output to display the measurement result; The PLC phase difference checker is equipped with a voltage generator, a measuring relay, a PLC programmable controller (2) and a measurement result display optical plate (1) in the housing; when performing a three-phase transmission line When measuring separately, connect the voltage generator and the measuring relay through the transmission line; The measuring relays J1, J2 and J3 in the PLC phase difference calibrator are each composed of six sub-relays: J1 consists of six relays connected in parallel: J1-1, J1-2, J1-3, J1-4, J1-5, J1-6; J2 consists of six relays connected in parallel: J2-1, J2-2, J2-3, J2-4, J2-5, J2-6; J3 consists of six relays connected in parallel: J3-1, J3-2, J3-3, J3-4, J3-5, J3-6; The action voltage of J1-1, J 2-1, J3-1 is set to about 50 volts; The operating voltage of J1-2, J 2-2, J3-2 is set to about 100 volts; The operating voltage of J1-3, J 2-3, J3-3 is set to about 150 volts; The operating voltage of J1-4, J 2-4 and J3-4 is set to about -50 volts; The action voltage of J1-5, J 2-5, J3-5 is set to about -100 volts; The operating voltage of J1-6, J 2-6 and J3-6 is set to about -150 volts; Input the contacts of the above 18 relays as switch inputs to the digital input terminals of the programmable controller in the following order: The order from lowest to highest is: J1-1, J1-2, J1-3, J1-4, J1-5, J1-6, J2-1, J2-2, J2-3, J2-4, J2-5, J2-6, J3-1, J3-2, J3-3, J3-4, J3-5, J3-6; The voltage generator adopts the mode of working voltage of DC power supply, and the working voltage of DC power supply adopts 80V and 100V. 2. The method according to claim 1 to realize the phase difference verification of lines with PLC, characterized in that: the DC power supply can be composed of dry batteries connected in series or in parallel, or can be composed of 220V alternating current through transformer, rectification, filtering, voltage stabilization loop gets. the 3. The method according to claim 1 to realize line phase difference verification with PLC, characterized in that: the DC power supply can be changed to other large and small operating voltages, and the corresponding 18 relays of relays J1, J2, and J3 The operating voltage setting value should also change accordingly with the size of the DC power supply operating voltage.

Images