CN113702871A - Intelligent line finder for secondary direct-current power supply without power failure of transformer substation - Google Patents

Abstract

The invention provides an intelligent tracer for a secondary DC power supply without power failure in a substation, which belongs to the technical field of power cable tracing, and includes a main control module, a measurement module, a man-machine exchange module, and a storage module; the main control module includes a CPU, and The monitoring module and the resistance switching module are respectively connected to the CPU, and the resistance switching module is put into resistance when the measurement is completed; the measurement module, the man-machine exchange module, and the storage module are all connected with the CPU; the The monitoring module includes a signal processor connected to the resistance switching module and an AD collector connected to the signal processor; the resistance switching module includes an input voltage dividing resistor, a sampling resistor and a detection resistor. The invention adopts the non-power-off mode, instantaneous high resistance "grounding", locates the direction of the DC power supply, greatly improves the work efficiency of later elimination and major repair and technical transformation, and has significant economic and social benefits.

Description

A kind of intelligent tracer for secondary DC power supply without power failure in substation

technical field

The invention relates to the technical field of power cable tracing, in particular to an intelligent tracer for a secondary direct current power supply without power failure in a substation.

Background technique

With the rapid development of various power industries, the demand for power cables such as urban power grid transformation is increasing, and power cables are increasingly used in power systems and various fields of production and life. Cable lines in the same city are directly buried underground or laid in a dedicated channel, and the direction of the cables cannot be determined after direct burial and laying. In the special cable channel, the cables are generally laid densely, and there are even cable lines with direct burial, special cable channels and cable passages through pipes. When tracing the DC power supply, some cables do not have any markings, and the direction and purpose of the cables cannot be clearly defined. Therefore, it is very difficult to find the DC power supply, which is time-consuming and labor-intensive, which seriously affects the maintenance efficiency and power grid security.

The patent document with the publication number of CN 112305620 A discloses a cable tracing identification device and a tracing method. The device includes: a signal generator, including: a signal generating circuit for generating a message signal and setting a high-frequency signal; A signal synthesis circuit for converting the message signal and the set high-frequency signal to obtain a high-frequency carrier frequency modulation signal; a non-direct contact coupling clip, which is connected to the signal generator; a signal detector, including: A signal receiving antenna for receiving high-frequency carrier frequency modulation signals; a detection/demodulation module, including a detection module and a demodulation module, the detection module is used to obtain the detection value of the high-frequency carrier frequency modulation signal, and the demodulation module is used for Demodulate the high-frequency carrier frequency modulated signal to obtain the demodulated message; the detection value and demodulation message of the high-frequency carrier frequency modulated signal are detected and obtained by the signal detector at different positions, and then the direction of the cable to be identified is determined. However, the grounding resistance cannot be measured accurately, and the identification speed of the cable direction is slow.

Patent document with publication number CN 104459454 A discloses a broadband line finder, comprising a processor and a receiver connected with the processor through wireless signals, a broadband interface is provided on the top of the casing, and a joint is provided at the bottom of the casing, A signal receiving probe is plugged and connected to the connector, a signal wire is connected to the side wall of the casing, and the end of the signal wire is plugged with a pin, and the signal receiving probe and the signal wire are respectively connected with the modulation module, and the modulation module It is respectively connected with the wireless signal transmitter and the broadband interface, the output end of the wireless signal transmitter is connected with an antenna, and the antenna is rotatably connected to the top of the casing. The described broadband line finder, using the finder of this design, can use the probe to detect the line, so as to send the received signal to the processor through the wireless signal, and can use the pin to detect the line. It is very convenient and safe to use to detect some places that the probe cannot detect, however, the tracer does not recognize the cable direction.

SUMMARY OF THE INVENTION

In view of this, the present invention provides an intelligent line hunter for a secondary DC power supply without power interruption in a substation.

In order to solve the above-mentioned technical problems, the technical scheme adopted by the present invention is:

An intelligent tracer for uninterrupted secondary DC power supply in a substation, comprising a main control module, a measurement module, a man-machine exchange module, and a storage module; the main control module includes a CPU, a monitoring module and a resistor respectively connected to the CPU A switching module, the resistance switching module inputs resistance when the measurement is completed; the measurement module, the man-machine exchange module, and the storage module are all connected with the CPU.

Further, the monitoring module includes a signal processor connected to the resistance switching module, and an AD collector connected to the signal processor.

Further, the resistance switching module includes an input voltage dividing resistor, a sampling resistor and a detection resistor.

Further, the measurement module includes a digital sensor, and the output end of the digital sensor is connected to the signal processor.

Further, the man-machine exchange module includes a display screen and an alarm connected to the main control module.

Further, the storage module includes a single-chip microcomputer, an interface circuit connected with the single-chip microcomputer, and an SD card connected with the interface circuit.

Cable lines are usually directly buried underground or laid in special channels. Compared with overhead lines, they have the advantages of being free from external influences and occupying no ground and space. However, a problem that occurs during the maintenance process of the cable circuit is that the direction of the cable cannot be determined, and in order to save space in the dedicated channel, the cable laying is generally denser, coupled with the phenomenon of cable accumulation and cable interleaving, once the cable fails or the line is reconstructed It is difficult to find this cable when searching for it.

Commonly used methods of finding lines are: follow the vine and find the melon method. The staff starts from the beginning or end of the cable, and searches the past little by little along the cable until it reaches the target location. This method has low cost but very low efficiency. In addition, another method is the induction method, which uses the electromagnetic induction generated around the cable when it is energized to determine the cable, such as a commonly used wire hunter, but most of the detected AC cables are. For example, the patent document with the publication number of CN104020493A discloses a high-sensitivity line finder, which includes a signal transmitter (100) and a signal receiver (200), and the signal transmitter (100) includes a signal generation module (110) and an amplification module. (120) and a frequency dividing module (150), the signal generating module (110) generates a single-frequency main frequency signal, which is divided by the frequency dividing module (150) to form a frequency dividing signal and amplified by the amplifying module (120) to form an amplified signal. The module (120) is connected to the wire (130) and transmits an amplified signal through the wire (130); the signal receiver (200) includes a signal receiving module (210), an amplification module (220), an analog-to-digital conversion module (230), and a central control module (240), an audio signal generating module (250) and an indicator (270), the signal receiving module (210) receives the amplified signal transmitted by the signal transmitter (100) and sends it to the amplifying module (220) for amplification and then passes through analog-to-digital conversion The module (230) is converted into a digital signal, and the central control module (240) receives the digital signal, analyzes, processes and confirms it and issues a control command to the audio signal generation module (250), and the audio signal generation module (250) generates the audio signal and passes the indicator (270) instructions. The patent document with publication number CN102073000A discloses a wire-hunting device for indicating the core of a multi-core control cable, which can quickly find out the multi-core control cable and compare the audio wire finder of the core of the control cable. It consists of dual-function pair-seeking generator, audio signal receiver, and expandable core plug. The dual-function line-finding generation device includes a digital audio generation module and a buzzer and light-emitting comparison module. The audio signal receiver is wirelessly connected with the dual-function matching line generating device through the audio signal. The expandable core plug is connected with the dual-function pair-seeking generating device through wires. The beneficial effect of the wire-seeking device is that the target multi-core control cable can be quickly found in a work site where a large number of multi-core control cables exist, and the cores of the control cables can be compared, thereby reducing occupation of production resources and improving work efficiency. This type of tracer cannot quickly and accurately identify the direction of the DC power supply. Therefore, it is necessary to develop an intelligent tracer for the secondary DC power supply without power interruption in the substation.

Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention includes a main control module, a measurement module, a man-machine exchange module, and a storage module. The main control module includes a CPU, a monitoring module and a resistance switching module. The monitoring module completes the measurement of voltage and resistance, and the resistance switching module inputs resistance during measurement to meet the conditions of use of the measurement method. The measurement module includes a digital sensor, the output end is connected with the signal processor, and the signal is processed after detection and converted into an electronic signal.

In the present invention, one end of the secondary DC power source intelligent line seeker is merged into the DC loop on the feeder side, and the other end is grounded. The resistance value of the DC feeder branch to ground changes by adjusting the resistance switching module, and an early warning prompt is given. At this time, the corresponding If the leakage current or voltage of the device powered by the DC power supply changes and an audible and visual alarm is issued, the direction of the DC power supply of the branch can be judged. Then measure the DC voltage of the secondary line through the receiving measurement module, and the cable where the line where the measured voltage is too large or too small is the DC power cable. The invention adopts the non-power-off mode, instantaneous high resistance "grounding", locates the direction of the DC power supply, greatly improves the work efficiency of later elimination and major repair and technical transformation, and has significant economic and social benefits.

Description of drawings

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

FIG. 1 is a schematic diagram of Embodiment 1 of the present invention.

FIG. 2 is a schematic diagram of Embodiment 3 of the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings 1-2 of the embodiments of the present invention. Obviously, the described embodiments are some, but not all, embodiments of the present invention. Based on the described embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art fall within the protection scope of the present invention.

Example 1

As shown in FIG. 1 , the present embodiment provides an intelligent line hunter for a secondary DC power supply without power failure in a substation, including a main control module, a measurement module, a man-machine exchange module, and a storage module; the main control module includes a CPU, and a The monitoring module and the resistance switching module are respectively connected with the CPU, and the resistance switching module inputs resistance when the measurement is completed; the measurement module, the man-machine exchange module, and the storage module are all connected with the CPU.

The monitoring module includes a signal processor connected to the resistance switching module, and an AD collector connected to the signal processor.

The resistance switching module includes an input voltage dividing resistor, a sampling resistor and a detection resistor.

The measurement module includes a digital sensor, and the output end of the digital sensor is connected with the signal processor.

The man-machine exchange module includes a display screen and an alarm connected to the main control module.

The storage module includes a single-chip microcomputer, an interface circuit connected with the single-chip microcomputer, and an SD card connected with the interface circuit.

The single-chip microcomputer adopts MC9S12XS128 single-chip microcomputer. The interface circuit is constructed by transistor C1815 and resistor. The SD card is Kingston SD card. The full-duplex 8-bit SPI module of MC9S12XS128 single-chip microcomputer has 4 pins, which are respectively the main input and slave output pins MISO, and the main input and slave pins. Output pin MOSI, serial clock pin SCK, slave chip select pin SS. When the CS signal line is low, the host starts all bus transfers. The data is synchronously input from the MOSI pin of the microcontroller to the DA pin of the Micro SD card, the return data of the Micro SD card is synchronously input to the MISO pin of the microcontroller through the DO line, and the data is input and output synchronously on the rising edge of the CLK signal. The digital sensor is a highly integrated open-type digital sensor. The detection results are processed by a signal processor, which urges the signal to perform anti-interference and error-prevention processing and amplify it to the most sensitive level that can reflect the original signal. The processed signal is collected by the AD collector, converted into an electronic signal that can be recognized, and then fed back to the CPU, and finally the result is input to the man-machine exchange module and the storage module.

The amplifier circuit chip is AD620, which has the advantages of low price, high precision, high common mode rejection ratio, low noise, etc. It only needs to set an external gain resistor on the feedback circuit to set the circuit amplification factor to 1-10000 times, and its 8 The leaded SOIC package makes it small and suitable for small measurement circuits. Its highest common mode rejection ratio is 100dB, while the common mode rejection ratio of other commonly used op amp chips such as LM358 and LM353 is 80dB, so AD620 has better ability to suppress common mode and differential mode signals than common op amp chips. More suitable for the needs of this application.

One end of the secondary DC power source intelligent line seeker is merged into the DC circuit on the feeder side, and the other end is grounded, and the resistance value of the DC feeder branch to ground changes through precise and intelligent resistance adjustment, and an early warning prompt is given. When the leakage current or voltage of the power supply device changes and an audible and visual alarm is issued, the direction of the DC power supply of the branch can be judged. Then measure the DC voltage of the secondary line through the receiving measurement module, and the cable where the line where the measured voltage is too large or too small is the DC power cable.

Example 2

The present embodiment provides an intelligent tracer for the secondary DC power source without interruption of the substation, which is an improvement on the basis of Embodiment 1. In the present embodiment, the method for measuring the ground resistance is:

1. Put the detection branch including the detection resistance RT+ into the DC circuit, and measure the current on the detection resistance;

2. Put the detection branch including the detection resistance RT- into the DC circuit, and measure the current on the detection resistance. By adding the detection resistance to the bus bar twice, two different circuit relationships can be obtained, so as to calculate the resistance of the resistance to ground. value.

The voltage measurement method is:

1. Connect two voltage divider resistors and a sampling resistor in series between the positive and negative poles of the DC line; the value of the voltage divider resistor should be selected according to the amplifier circuit to avoid a large current on the sampling resistor and exceed the input limit of the subsequent circuit; while sampling The value of the resistor should not be too large. If the value of the sampling resistor is too large, the current flowing through it will be too small, the signal will be weak, and the measurement accuracy will be reduced;

2. Process the voltage signal at both ends of the acquisition resistor and input it into the signal processor, that is, perform anti-interference and error prevention processing and amplify the signal. The amplification process is to adjust the voltage across the acquisition resistor to the voltage range that can be recognized by the processor AD, and in this Amplify the signal within the range to reflect the most sensitive degree of the original signal;

3. The processed signal is input into the AD collector for collection; after the signal is processed, it is input into the AD collector for collection, so that the electrical signal is converted into an electronic signal that can be identified.

Example 3

As shown in FIG. 2 , this embodiment provides an intelligent tracer for a secondary DC power supply without power interruption in a substation, which is an improvement on the basis of Embodiment 2. The main control module further includes a modulation module, and the modulation module connected with the monitoring module and the CPU. The modulation module includes a low-pass filter connected with the AD collector and an operational amplifier connected with the low-pass filter. The low-pass filter removes the interference signal from the signal, and the signal is amplified by the operational amplifier, and then the result is transmitted to the CPU for recording, analysis and storage.

The above are the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the principles of the present invention, several improvements and modifications can be made. It should be regarded as the protection scope of the present invention.

Claims (6)

1. A substation uninterrupted secondary direct current power source intelligent line finder, is characterized in that: comprise main control module, measurement module, man-machine exchange module, storage module; Described main control module comprises CPU, and described CPU respectively phase The monitoring module and the resistance switching module are connected, and the resistance switching module inputs resistance when the measurement is completed; the measurement module, the man-machine exchange module and the storage module are all connected with the CPU. 2 . The intelligent tracer for uninterrupted secondary DC power supply in a substation according to claim 1 , wherein the monitoring module comprises a signal processor connected to the resistance switching module, and a signal processor connected to the resistance switching module. 3 . AD collector connected to the signal processor. 3. The intelligent tracer for uninterrupted secondary DC power supply in a substation according to claim 2, wherein the resistance switching module comprises an input voltage dividing resistor, a sampling resistor and a detection resistor. 4 . The intelligent tracer for uninterrupted secondary DC power supply in a substation according to claim 3 , wherein the measurement module comprises a digital sensor, and the output end of the digital sensor is connected to the signal processor. 5 . . 5 . The intelligent line hunter for a secondary DC power source without power interruption in a substation according to claim 4 , wherein the man-machine exchange module comprises a display screen and an alarm connected to the main control module. 6 . 6 . The intelligent line hunter for a secondary DC power supply without power failure in a substation according to claim 5 , wherein the storage module comprises a single-chip microcomputer, an interface circuit connected to the single-chip microcomputer, and an interface circuit connected to the single-chip microcomputer. 7 . connected SD card.

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