CN106526397B - An automatic and intelligent wire checking method for intelligent substations - Google Patents

Abstract

An automatic and intelligent wire checking method for intelligent substations belongs to the field of measurement. It is provided with a control unit, a power supply, a set of relays and a first test socket to form part A; a resistance matrix and a second test socket are set to form part B; the prefabricated cable plugs at both ends of the cable to be tested are inserted into the first The first and second test sockets; the control unit establishes the mapping relationship between the resistance matrix and the prefabricated cable plugs; sequentially controls each relay contact to perform "on" and "off" actions, and simultaneously detects the resistance between the core loops of the cables to be tested value; by controlling the "on" and "off" action behavior of each relay contact, and detecting the level change of each relay port, the on-off condition between the two ends of the cable to be tested can be judged; The connection sequence of each core wire of the cable to be tested on the prefabricated cable plug solves the problem of interlaced wiring of cables.

Description

An automatic and intelligent wire checking method for intelligent substations

technical field

The invention belongs to the field of measurement, in particular to a detection device for detecting faults in cables, transmission lines or networks.

Background technique

Smart substation is the use of advanced, reliable, integrated and environmentally friendly intelligent equipment, with the basic requirements of total station information digitization, communication platform networking, and information sharing standardization, and automatically completes basic functions such as information collection, measurement, control, protection, measurement and detection. At the same time, it has a substation that supports advanced functions such as real-time automatic control of the power grid, intelligent regulation, online analysis and decision-making, and collaborative interaction.

In the power transmission and relay protection system, the intelligent substation system can usually be divided into three layers: the process layer, the interval layer and the station control layer. The process layer includes intelligent equipment, merging units and intelligent terminals composed of primary equipment and intelligent components, and completes the power distribution, transformation, transmission and related functions of substation power distribution, measurement, control, protection, metering, state monitoring, etc.; Secondary equipment such as electrical protection device, measurement and control device, fault recorder, etc., realizes the function of using the data of one interval and acting on the primary equipment of the interval, that is, communicating with various remote input/output, intelligent sensors and controllers; station control layer It includes subsystems such as automation system, station domain control system, communication system, time synchronization system, etc., realizes measurement and control functions for the whole station or more than one secondary equipment, completes data acquisition and monitoring control, operation blocking and synchrophasor acquisition, Electric energy collection, protection information management and other related functions.

It can be seen that the biggest difference between smart substations and traditional substations is reflected in three aspects: 1. The primary equipment is intelligent; 2. The equipment maintenance is state-based; 3. The secondary equipment is networked.

In the process of installation and commissioning of the secondary system of the intelligent substation, a large number of cables need to be used. However, after the cables are laid, the cable-to-line is a very important process.

At present, the following tools are commonly used when connecting cables: telephones, walkie-talkies, multimeters, etc. When connecting cables, two or more people must cooperate, and the consistent signals of the connecting lines must be agreed in advance, and one party and the other party must coordinate and cooperate. A common method is that one person shorts the wires at one end of the cable, and the other uses a multimeter to measure the wires one by one at the other end of the cable. During the measurement process, a communication tool such as a telephone is used to communicate in real time. When determining the current measurement cable , set the same flag.

The date of the authorization announcement is November 13, 2013. In the Chinese utility model patent with the authorization announcement number CN 203289523U, a "phone line checking device" is disclosed, which includes: a multimeter dial, a button, a microphone, and an earpiece for A display screen that displays the multimeter's measurement information or call information, a paddle switch used for switching functions between the telephone and the multimeter, and a detection line interface; the multimeter dial and the display screen are connected to the multimeter's internal circuit; the buttons, microphones, earpieces and The display screen is connected to the telephone circuit board; the detection line interface is connected to the dial switch, and the dial switch is connected to the internal circuit of the multimeter and the telephone circuit board. The telephone line checking device integrates the telephone and the multimeter, realizes the switching of functions through a paddle switch, is convenient to carry, and is convenient to use. Although the technical solution uses a multimeter and a paddle switch to solve the problems of fast display, easy display and judgment, and fast switching, it has the disadvantages of taking a long time in the entire alignment process and being prone to errors.

How to perform alignment work quickly and efficiently, reduce the consumption of manpower and material resources in the alignment process, and improve work efficiency, is an urgent problem that needs to be solved in the current actual construction process.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide an automatic and intelligent wire checking method for an intelligent substation. It uses diodes to identify the connection sequence of each core of the cable under test on the prefabricated cable plug, and judges the on/off relationship between the corresponding core and core of the cable to be tested by detecting the resistance value connected in the circuit string. Prefabricated cables in batches, using automated testing methods, can quickly check the manufacturing quality of prefabricated cables in smart substations, realize pre-installation inspections and prefabricated cable inspections before power-on, quickly discover damage and misplacement during prefabricated cable installation, and ensure cable laying , The engineering quality of joint production greatly improves the efficiency of line inspection, and helps to significantly shorten the construction period of intelligent substations.

The technical scheme of the present invention is to provide an automatic and intelligent wire-checking method for smart substations, which is characterized in that the automatic and intelligent wire-checking method adopts the following methods for quick wire-checking and Determine whether the connection sequence of each core wire of the cable to be tested on the prefabricated cable plug is correct:

Set up a control unit, a power supply, a group of relays and a first test socket to form part A;

Wherein, the control unit controls the "on" or "off" of each relay contact, thereby realizing the on-off function of the electronic switch

The first test socket is an n-core wire socket; n is the number of cores of the cable to be tested;

According to the number of cores of the cable to be tested, n+2 relays are set, and each relay corresponds to a normally open contact;

The lower ends of the relay contacts 1 to n-1 in the relay contacts are respectively connected with the core wire jacks of the cables to be tested from 1 to n-1, and the upper ends of the relay contacts 1 to n-1 are connected to the positive terminal of the power supply. connect;

The lower ends of the relay contacts n to n+2 in the relay contacts are respectively connected to the core wire jacks of the cables to be tested from 2 to n, and the upper ends of the relay contacts n to n+2 are connected to the negative terminal of the power supply;

Set up a resistance matrix and a second test socket to form part B in combination;

Wherein, the second test socket is an n-core wire socket; n is the number of cores of the cable to be tested;

For the resistance matrix, according to the number of cores n of the cable to be tested, n-1 resistance matrixes are set, which are respectively arranged in parallel between the n core wire jacks of the second test socket;

Insert the prefabricated cable plugs at both ends of the cable to be tested into the first and second test sockets respectively;

The control unit establishes the mapping relationship between the resistance matrix and the prefabricated cable plug;

The control unit controls each relay contact in turn to perform "on" and "off" actions, and simultaneously detects the resistance value between each cable core loop to be tested;

The control unit controls the "on" and "off" actions of each relay contact, and detects the level change of each relay port, thereby judging the on-off condition between each core wire at the two ends of the cable to be tested;

The control unit uses diodes to identify the connection sequence of each core wire of the cable to be tested on the prefabricated cable plug, so as to solve the problem of cross-connection of cables.

Specifically, the resistance matrix is composed of a resistor and a diode connected in series; wherein, the x-th core wire of the cable to be tested is connected to the x-th diode's anode through the x-th resistor, and the x-th diode's cathode is connected , which is connected to the core wire of the cable to be tested No. x+1; where x is the number of the core wire of the cable to be tested, and the value ranges from 1 to n, where n is the number of cores of the cable to be tested.

The control unit is a single chip computer or a PLC.

Each I/O port of the control unit is connected to the control coil of each relay correspondingly, and by outputting a high level or a low level to the control coil, the "on" or "off" of the corresponding relay contact is controlled.

The control unit controls the corresponding resistance matrix of each relay contact connection according to the number of cores of the cable to be tested, and judges the on/off between the corresponding cores of the cable to be tested by detecting the resistance value connected in series in the loop. relation.

The PLC has a built-in wire-checker kernel program, which controls the action behavior of each relay contact and senses the port level change of each relay contact, thereby judging the on/off condition of the two ends of the cable to be tested.

The automatic intelligent wire checking method is used for checking wires before the installation of prefabricated cables in smart substations, so as to check the manufacturing quality of the prefabricated cables.

The automatic and intelligent wire checking method for smart substations is used for checking wires of prefabricated cables before the smart substation is powered on, so as to check the damage and misplacement of the prefabricated cables during the installation process.

The technical solution of the present invention also provides an automatic intelligent wire checking device that works according to the intelligent wire checking method of claim 1, characterized in that:

Set first and second test sockets; the test sockets are n-core wire sockets; n is the number of cores of the cable to be tested;

At the first test socket, according to the number of cores of the cable to be tested, n+2 relays are set, and each relay corresponds to a normally open contact;

set a power supply;

The lower ends of the relay contacts 1 to n-1 in the relay contacts are respectively connected with the core wire jacks of the cables to be tested from 1 to n-1, and the upper ends of the relay contacts 1 to n-1 are connected to the positive terminal of the power supply. connect;

The lower ends of the relay contacts n to n+2 in the relay contacts are respectively connected to the core wire jacks of the cables to be tested from 2 to n, and the upper ends of the relay contacts n to n+2 are connected to the negative terminal of the power supply;

At the second test socket, according to the number of cores n of the cable to be tested, n-1 resistance matrices are set, and the resistance matrixes are respectively arranged in parallel between the core wire jacks of the second test socket;

The resistance matrix is composed of a resistor and a diode connected in series; wherein, the core wire of No. x of the cable to be tested is connected to the anode of No. x+1 is the core wire connection of the cable to be tested; where x is the number of the core wire of the cable to be tested, the value ranges from 1 to n, and n is the number of cores of the cable to be tested;

Set up a control unit to control the "on" or "off" of each relay contact, thereby realizing the on-off function of the electronic switch;

Each I/O port of the control unit is respectively connected with the control coil of each relay, and by outputting a high level or a low level to the control coil, the "on" or "off" of the corresponding relay contact is controlled;

The control unit, the power supply, the relay group and the first test socket are combined together to form part A, and the resistance matrix and the second test socket are combined together to form part B.

During actual work, insert the prefabricated cable plugs at both ends of the cable to be tested into the first and second test sockets respectively;

The control unit establishes the mapping relationship between the resistance matrix and the prefabricated cable plug;

The control unit controls each relay contact to perform "on" and "off" actions in turn, and at the same time detects the resistance value between each cable core loop to be tested, and controls the "on" and "off" actions of each relay contact. behavior, and detect the level change of each relay port, thereby judging the continuity between the first and last ends of each core wire of the cable to be tested;

The control unit identifies the connection sequence of each core wire of the cable to be tested on the prefabricated cable plug through the diode, so as to solve the problem of cable staggered wiring;

The automatic intelligent wire checking device is used for checking wires before the installation of prefabricated cables in smart substations, so as to check the manufacturing quality of prefabricated cables;

The automatic intelligent wire checking device is used for checking wires of prefabricated cables before power-on of the intelligent substation, so as to check the damage and misplacement of the prefabricated cables during the installation process.

Compared with the prior art, the advantages of the present invention are:

1. For a large number of prefabricated cables in substations, the method of level measurement is used to quickly judge the manufacturing quality of the cables and cable heads to be tested, especially suitable for the inspection of prefabricated cables in smart substations before installation;

2. The connection sequence of each core of the cable to be tested on the prefabricated cable plug is identified by diodes, which can effectively solve the problem of interlaced wiring of cables;

3. The whole process of testing and line checking is carried out automatically, which greatly improves the work efficiency and avoids human operation errors.

Description of drawings

Fig. 1 is a schematic diagram of a system composition module of the present invention;

Fig. 2 is the system principle schematic diagram of the present invention;

Fig. 3 is the working circuit circuit diagram of the present invention when the wiring is normal;

Fig. 4 is the working circuit circuit diagram of the present invention when wiring is wrong;

Figure 5 is a block diagram of the work flow of the present invention.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and embodiments.

Compared with traditional substations, the installation and commissioning of smart substations is characterized by simplicity, repetition and networking. Taking the secondary cable installation and inspection as an example, the secondary cables of the smart substation are all prefabricated cables, and prefabricated cable sockets are installed at the equipment connected to the two ends of the cables, which can be directly inserted during on-site installation, and the insertion process is directional . Therefore, the whole process is simple and highly repeatable.

Although the installation process of the secondary cable is simple, the verification of its correctness is consistent with the traditional cable inspection process, that is, each core of the cable must be wired correctly, and no open circuit, short circuit, or wrong connection can occur. This requirement poses new challenges to the secondary cable inspection of smart substations, which can be summarized as the following three points:

1) How to solve the problem of checking the cables before installing large quantities of prefabricated cables?

2) How to solve the problem that the cable core is not visible during the prefabricated cable inspection process?

3) How to solve the error-prone problem of human eye recognition of prefabricated cable plugs?

The technical solution is designed to solve the above three problems.

In FIG. 1 , the automatic and intelligent wire checking device (referred to as a wire checking device for short, the same below) of the technical solution includes four core components.

Component 1: PLC programmable controller. It is used to execute the wire-checker kernel program, and establish the connection relationship with the resistance matrix by controlling the relay contacts. At the same time, the PLC senses the level change of the relay port and judges the on-off condition of the predicted cable according to the set procedure. The open circuit, short circuit, and wiring correspondence of each core of the prefabricated cable at both ends can be displayed on the LCD screen of the PLC.

Component 2: Relay group. It is used to execute PLC instructions, connect prefabricated cables and resistance matrices, and establish mapping relationships.

Component Three: Resistor Matrix. It consists of circuit boards, resistors, diodes and other components.

Component four: first and second test sockets. When used for wire checking, insert the plugs at both ends of the prefabricated cable into the corresponding test sockets to establish an electrical circuit connection.

The control unit, the power supply, the relay group and the first test socket are combined to form part A, and the resistance matrix and the second test socket are combined to form part B. In this way, the entire automatic intelligent wire checking method is Macroscopically, it is only composed of two parts, which is easy to carry and operate on site.

As shown in FIG. 1 , in this technical solution, an automatic intelligent wire checking device is provided, which performs automatic wire checking according to the following method:

The automatic intelligent wire checking device is provided with first and second test sockets; the test sockets are n-core wire sockets; n is the number of cores of the cable to be tested;

At the first test socket, according to the number of cores of the cable to be tested, n+2 relays are set, and each relay corresponds to a normally open contact;

provided with a power supply;

The lower ends of the relay contacts 1 to n-1 in the relay contacts are respectively connected with the core wire jacks of the cables to be tested from 1 to n-1, and the upper ends of the relay contacts 1 to n-1 are connected to the positive terminal of the power supply. connect;

The lower ends of the relay contacts n to n+2 in the relay contacts are respectively connected to the core wire jacks of the cables to be tested from 2 to n, and the upper ends of the relay contacts n to n+2 are connected to the negative terminal of the power supply;

At the second test socket, according to the number of cores n of the cable to be tested, n-1 resistance matrices are set, and the resistance matrixes are respectively arranged in parallel between the core wire jacks of the second test socket;

The resistance matrix is composed of a resistor and a diode connected in series; wherein, the core wire of No. x of the cable to be tested is connected to the anode of No. x+1 is the core wire connection of the cable to be tested; where x is the number of the core wire of the cable to be tested, the value ranges from 1 to n, and n is the number of cores of the cable to be tested;

A control unit is provided to control the "on" or "off" of each relay contact, thereby realizing the on-off function of the electronic switch;

Each I/O port of the control unit is respectively connected with the control coil of each relay, and by outputting a high level or a low level to the control coil, the "on" or "off" of the corresponding relay contact is controlled;

The control unit, the power supply, the relay group and the first test socket are combined together to form part A, and the resistance matrix and the second test socket are combined together to form part B.

In Figure 2, a schematic diagram of the principle of the automatic intelligent wire checking device designed by taking the four-core prefabricated cable plug as an example is given.

The design principle of the wire checker is mainly completed by establishing the mapping relationship between the resistance matrix and the prefabricated cable plug.

The main points of its design include: identifying the connection sequence of each core of the prefabricated cable on the prefabricated cable plug through diodes to solve the problem of staggered wiring of cables; connecting the resistance matrix through the relay contacts according to the number of prefabricated cable cores, and determining the resistance value connected in series by the detection loop. The on-off relationship between the corresponding core and the core is obtained; the core program of the wire checker is written, the action behavior of the relay is controlled by the PLC, and the level change of each relay port is sensed, thereby judging the on-off between the two ends of each core wire of the prefabricated cable Happening.

Specifically, first and second test sockets are provided; the test sockets are 4-core wire sockets; 4 is the number of cores of the cable to be tested;

In the first test socket, set 6 relays according to the number of cores of the cable to be tested 4, each relay corresponds to a normally open contact (represented by S1, S2, S3, S4, S5, S6 in the figure);

Set a power supply V1;

The lower ends of the relay contacts S1 to S3 in the relay contacts are respectively connected to the core wire jacks of the cables to be tested from No. 1 to No. 3, and the upper ends of the relay contacts of No. S1 to S3 are connected to the positive terminal of the power supply;

The lower ends of the relay contacts S2 to S6 in the relay contacts are respectively connected to the core wire jacks of the cables to be tested from No. 2 to No. 4, and the upper ends of the relay contacts of No. S2 to S6 are connected to the negative terminal of the power supply;

In the second test socket, according to the number of cores of the cable to be tested, 3 resistance matrices are set, and the resistance matrices are respectively arranged in parallel between the core wires of the cable to be tested;

Set up a control unit PLC to control the "on" or "off" of each relay contact, thereby realizing the on-off function of the electronic switch;

The resistance matrix consists of a resistor and a diode connected in series; among them, the No. 1 core wire of the cable to be tested, through the No. 1 resistor, is connected to the positive pole of the No. 1 diode, and the negative pole of the No. 1 diode is connected to the No. 2 The core wire of the test cable is connected; and so on, the No. 3 core wire of the cable to be tested, through the No. 3 resistor, is connected to the positive pole of the No. 3 diode, and the negative pole of the No. 3 diode is connected to the No. 4 core wire of the cable to be tested. .

Combined with Figure 3 and Figure 4, the specific action behavior of the wire checker is represented by the following example (take the wire check of a four-core cable as an example):

In actual operation, the operation steps are shown in Figure 5.

Before checking the wiring, the user needs to connect the two ends of the wire to the A and B terminals of the design, and then press the "F1" button through the PLC screen prompt, the calibration device can automatically complete the calibration and display the relevant results on the screen. On the result, if the user wants to check the last line calibration result about the line short circuit, the line open circuit and the line wrong line, he can also view it freely by pressing the relevant button.

The automatic and intelligent line checking method of this technical solution has obvious advantages in specific application occasions, which are listed as follows:

Occasion 1: Check the wiring of the prefabricated cables in the smart substation before installation to check the manufacturing quality of the prefabricated cables. The operation of the wire checker is extremely simple, and only requires the operator to have basic knowledge of wire check.

Occasion 2: Check the prefabricated cables before the smart substation is powered on. Used to check for damage and misplacement during prefabricated cable installation.

By adopting the automatic and intelligent wire checking method of this technical solution, the checking process of a prefabricated cable does not take one minute, compared with a few minutes or even longer time for checking wires of a conventional cable (if the cable is faulty, checking is required), the checking efficiency of the wire checking device is very high. high.

Field work experience shows that all about 200-300 prefabricated cables in a 110kV smart substation can be inspected in half a day. If the supplier needs to modify it, and after the re-inspection time is counted, all the work can be completed in one day. Compared with the traditional working time of 2 people for 3-4 days, the efficiency is improved by about 80%.

Because the technical scheme of the present invention uses diodes to identify the connection sequence of each core of the cable under test on the prefabricated cable plug, and determines the on/off relationship between the corresponding core of the cable under test and the core by detecting the resistance value connected in series by the loop; The operation is extremely simple, and only requires the operator to have basic knowledge of line checking.

The technical solution of the present invention has extremely obvious advantages in specific application occasions, and is especially suitable for checking the wiring of the prefabricated cables in the smart substation before installation and laying, so as to check the manufacturing quality of the prefabricated cables; To check the damage and misplacement of prefabricated cables during installation. It can greatly reduce the consumption of manpower and material resources in the process of line checking, and greatly improve the efficiency of line checking.

The invention can be widely used in the field of design and manufacture of cable testing devices in substations.

Claims (10)

1. an automatic intelligent wire checking method for intelligent substation, it is characterized in that described automatic intelligent wire checking method, for the prefabricated cables to be tested of smart substations, adopt the following methods to quickly check wires and judge each core of the cable to be tested Is the order of connection of the wires on the prefabricated cable plugs correct: Set up a control unit, a power supply, a group of relays and a first test socket to form part A; Wherein, the control unit controls the "on" or "off" of each relay contact, thereby realizing the on-off function of the electronic switch; The first test socket is an n-core wire socket; n is the number of cores of the cable to be tested; According to the number of cores of the cable to be tested, n+2 relays are set, and each relay corresponds to a normally open contact; The lower ends of the relay contacts 1 to n-1 in the relay contacts are respectively connected to the core wire jacks of the cables to be tested from 1 to n-1, and the upper ends of the relay contacts 1 to n-1 are connected to the positive terminal of the power supply. connect; The lower ends of the relay contacts n to n+2 in the relay contacts are respectively connected to the core wire jacks of the cables to be tested from 2 to n, and the upper ends of the relay contacts n to n+2 are connected to the negative end of the power supply; Set up a resistance matrix and a second test socket to form part B in combination; Wherein, the second test socket is an n-core wire socket; n is the number of cores of the cable to be tested; For the resistance matrix, according to the number of cores n of the cable to be tested, n-1 resistance matrixes are set, which are respectively arranged in parallel between the n core wire jacks of the second test socket; Insert the prefabricated cable plugs at both ends of the cable to be tested into the first and second test sockets respectively; The control unit establishes the mapping relationship between the resistance matrix and the prefabricated cable plug; The control unit controls each relay contact in turn to perform "on" and "off" actions, and simultaneously detects the resistance value between each cable core loop to be tested; The control unit controls the "on" and "off" actions of each relay contact, and detects the level change of each relay port, thereby judging the on-off condition between each core wire at the two ends of the cable to be tested; The control unit uses diodes to identify the connection sequence of each core wire of the cable to be tested on the prefabricated cable plug, so as to solve the problem of cross-connection of cables. 2. The automatic intelligent wire-checking method for intelligent substation according to claim 1, wherein the resistance matrix is formed by a resistor and a diode connected in series; No. x resistor is connected to the positive pole of the No. x diode, and the negative pole of the No. x diode is connected to the No. x+1 No. 1 to n, where n is the number of cores of the cable to be tested. 3. The automatic and intelligent wire-checking method for an intelligent substation according to claim 1, wherein the control unit is a single-chip microcomputer or a PLC. 4. The automatic and intelligent wire-checking method for an intelligent substation according to claim 1, wherein each I/O port of the control unit is connected to the control coil of each relay correspondingly, and the control coil outputs a high level or low level to control the "on" or "off" of the corresponding relay contact. 5. The method for automatic and intelligent wire checking for intelligent substations according to claim 1, wherein the control unit controls the respective resistance matrices of each relay contact to connect to the corresponding resistance matrix according to the number of cores of the cable to be tested, and passes the detection loop. The resistance value connected in the middle string is used to determine the on/off relationship between the corresponding core and core of the cable to be tested. 6. The automatic intelligent wire checking method for intelligent substation according to claim 3, characterized in that the PLC has a built-in wire checking kernel program, and by controlling the action behavior of each relay contact, and feeling the behavior of each relay contact. The level of the port changes, thereby judging the on/off status of the two ends of the cable to be tested. 7. The automatic intelligent wire checking method for intelligent substation according to claim 1, characterized in that the automatic intelligent wire checking method is used for checking wires before the prefabricated cables of the smart substation are installed to check the manufacturing quality of the prefabricated cables . 8. The automatic and intelligent wire-checking method for smart substations according to claim 1, characterized in that the described automatic and intelligent wire-checking methods for smart substations are used for wire checking of prefabricated cables before the smart substation is powered on, to check for damage and misplacement during prefabricated cable installation. 9. An automatic intelligent wire-checking device working according to the described intelligent wire-checking method of claim 1, is characterized in that: Set first and second test sockets; the test sockets are n-core wire sockets; n is the number of cores of the cable to be tested; At the first test socket, according to the number of cores of the cable to be tested, n+2 relays are set, and each relay corresponds to a normally open contact; set a power supply; The lower ends of the relay contacts 1 to n-1 in the relay contacts are respectively connected with the core wire jacks of the cables to be tested from 1 to n-1, and the upper ends of the relay contacts 1 to n-1 are connected to the positive terminal of the power supply. connect; The lower ends of the relay contacts n to n+2 in the relay contacts are respectively connected to the core wire jacks of the cables to be tested from 2 to n, and the upper ends of the relay contacts n to n+2 are connected to the negative terminal of the power supply; At the second test socket, according to the number of cores n of the cable to be tested, n-1 resistance matrices are set, and the resistance matrixes are respectively arranged in parallel between the core wire jacks of the second test socket; The resistance matrix is composed of a resistor and a diode connected in series; wherein, the core wire of No. x of the cable to be tested is connected to the anode of No. x+1 is the core wire connection of the cable to be tested; where x is the number of the core wire of the cable to be tested, the value ranges from 1 to n, and n is the number of cores of the cable to be tested; Set up a control unit to control the "on" or "off" of each relay contact, thereby realizing the on-off function of the electronic switch; Each I/O port of the control unit is respectively connected with the control coil of each relay, and by outputting a high level or a low level to the control coil, the "on" or "off" of the corresponding contact of the relay is controlled; The control unit, the power supply, the relay group and the first test socket are combined together to form part A, and the resistance matrix and the second test socket are combined together to form part B. 10. The automatic intelligent wire checking device according to claim 9, wherein the prefabricated cable plugs at both ends of the cable to be tested are respectively inserted into the first and second test sockets correspondingly; The control unit establishes the mapping relationship between the resistance matrix and the prefabricated cable plug; The control unit controls each relay contact to perform "on" and "off" actions in turn, and at the same time detects the resistance value between each cable core loop to be tested, and controls the "on" and "off" actions of each relay contact. behavior, and detect the level change of each relay port, thereby judging the continuity between the first and last ends of each core wire of the cable to be tested; The control unit identifies the connection sequence of each core wire of the cable to be tested on the prefabricated cable plug through the diode, so as to solve the problem of cable staggered wiring; The automatic intelligent wire checking device is used for checking wires before the installation of prefabricated cables in smart substations, so as to check the manufacturing quality of prefabricated cables; The automatic intelligent wire checking device is used for checking wires of prefabricated cables before power-on of the intelligent substation, so as to check the damage and misplacement of the prefabricated cables during the installation process.