CN206945928U - Fault detect positioner is scurried into a kind of Portable exchange - Google Patents

Abstract

At present, most of the equipment for AC channeling fault detection are sampling and fixed installation, but the fixed installation cannot judge and locate the specific fault point. There are also some mobile ground fault finding instruments that treat AC intrusion faults as ordinary ground faults, and perform fault troubleshooting by injecting a low-frequency signal. The utility model belongs to the technical field of electric power detection, in particular to a portable mobile AC intrusion fault detection and positioning device, which includes a host signal source and a hand-held detector. The host signal source is used to monitor whether there is AC intrusion in a DC system and display System voltage and AC component components, and send data information to the handheld detector; the handheld detector conducts AC intrusion fault point troubleshooting based on the received data information. The utility model adopts a non-fixed installation method, and uses a portable and mobile installation structure to move to find the fault point and locate the specific fault location where the AC breaks in.

Description

A portable mobile AC break-in fault detection and positioning device

technical field

The utility model belongs to the technical field of electric power detection, in particular to a portable mobile AC break-in fault detection and positioning device.

Background technique

The DC power supply system is a system that provides power for protection, and its stability and reliability directly affect the working conditions of protection. Among them, the AC intrusion into the DC power system is one of the main faults that affect the stability and reliability of the DC power system. It can directly lead to protection malfunctions, resulting in serious system failures. At present, there are many domestic technical solutions for alarming and line selection devices, patents, and journals for AC intrusion into DC power supply systems, such as: AC intrusion into DC power supply alarm device for substations (CN201220534548.0), a DC power supply system for substations The AC intrusion warning monitoring device (201310698981.7), the non-injection DC system ground fault finding method and its device (201310513399.9), etc., but most of the existing products and technical solutions do not have insulation monitoring devices for DC power systems. AC intrusion detection function; a small number of DC system insulation monitoring devices have the functions of AC intrusion alarm and line selection, and can also record AC waveforms, but they simply have the ability to monitor AC intrusion into DC system faults, and The alarm and line selection function are just functions, and the line selection function can only determine that the AC channeling fault occurs on a certain feeder, and there is no way to determine the specific location of the fault on the feeder line, which will bring a lot of trouble to the on-site troubleshooting and processing. Difficulties. Although there are some portable ground fault finding devices with similar functions at present, they basically use the method of injecting signals.

From the above description, it can be seen that the main disadvantages of existing products and technologies are:

First, most of the current products or technical solutions only have the functions of monitoring and line selection for the faults of AC into DC power systems, and they are all fixed installations, and there is no way to determine the specific fault point.

Second, some portable ground fault finding equipment basically adopts the principle of injecting signals, and treats AC intrusion faults as ordinary ground faults.

Contents of the invention

In order to solve the above problems, the utility model provides a portable mobile AC break-in fault detection and positioning device, the specific technical solution is as follows:

A portable mobile AC break-in fault detection and positioning device, characterized in that it includes a host signal source and a hand-held detector; the host signal source includes a voltage dividing sampling unit, an isolation unit, an amplification circuit unit, an AD sampling unit, and an MCU processing unit, a data storage unit, and an output unit; the divided voltage sampling unit includes an AC signal source, a resistor R1, a resistor R2, and a resistor R3; the frequency of the AC signal source is 50 Hz, and is used to generate an AC signal; the isolation unit includes a capacitor C, photoelectric isolation circuit; the photoelectric isolation circuit includes an isolation linear optocoupler; the isolation linear optocoupler is an 8-fold amplification relationship; the amplifying circuit unit includes a low-pass amplifier; the AC signal is divided by a resistor R1 and a resistor R2 After being pressed, it is input to the capacitor C, and then input to the photoelectric isolation circuit, amplifier circuit unit, AD sampling unit, and MCU processing unit in sequence after being sampled by the resistor R3; the AC signal is divided into two signals after being processed and output by the MCU processing unit, one The signal is input to the storage unit for storage, and another signal is input to the output unit; the handheld detector includes a clamp transformer, an amplification filter circuit module, an AD sampling module, a wireless receiving module, a main processor MCU module, a display module, an alarm Output module; the clamp transformer detects the AC fault point and the detected signal is sequentially input to the amplification filter circuit module, AD sampling module, and main processor MCU module; The data information sent by the signal source is output and input to the main processor MCU module; the main processor MCU module calculates the data information output from the wireless receiving module and the signal output from the AD sampling module and judges whether there is an AC break-in fault , and display the current waveform of the signal through the display module, and at the same time output whether there is an AC break-in fault through the alarm output module.

Further, the AD sampling unit uses a 12-bit AD chip for sampling, and the reference voltage is 2.5V.

Further, the output unit includes a wireless output module and a liquid crystal display module.

Further, the value parameters of the resistors R1 and R2 are 500k/1W, the value parameters of the resistor R3 are 190 ohms, the value parameters of the capacitor C are 105/400V, and the amplification factor of the amplifying circuit unit is 40 times.

Further, what the MCU processing unit and the main processor MCU module select is the STM32 series single-chip microcomputer of ST Company as the CPU; the MCU processing unit uses the FFT algorithm to perform Fourier transform on the sampled digital signal sequence.

Further, the display module includes a liquid crystal display; the alarm output module includes voice prompts.

Further, the hand-held detector receives data information sent from the host signal source through the wireless receiving module, and the hand-held detector and the host signal source only need to communicate once, and the communication range of the communication is within 10 meters. The distance between the hand-held detector and the host signal source during the fault point is not limited.

Further, the MCU processing unit and the main processor MCU module adopt STM32 series single-chip microcomputer as the CPU, the system clock is 72M, and the minimum single instruction cycle is 13.9nS; the AC signal of 50Hz collects 40 data per cycle, and each sampling data interval is 0.5 mS, can record the incoming AC signal waveform within 60mS, and the warning time is less than 0.2S.

The beneficial effects of the utility model are:

1. The utility model is suitable for DC power supply systems of different voltage levels such as 220V/110V/48V in substations or power plants;

2. The utility model can detect AC break-in faults with various amplitudes within 0V to 285V;

3. The utility model can monitor and alarm the AC instantaneously entering the DC power supply system for less than 0.2 seconds, and record the AC waveform;

4. The utility model can locate the fault branch and the specific fault point that have entered the AC, and the mobile search method can find the fault point more quickly and deal with the fault in time;

5. The utility model adopts the principle of non-injection signal to directly detect the incoming AC signal without any influence on the DC power system;

6. In the case of resistive AC intrusion, the utility model automatically selects a suitable capacitive load between the DC power bus and the earth according to the amplitude of the intruded AC voltage, so that the AC power supply can be reduced. The AC amplitude of the intrusion into the DC power system can reduce the risk of protection malfunction caused by the intrusion of AC power in the DC power system.

7. The utility model is conducive to improving the operation and management level of the DC power supply system of the substation or power plant, and is conducive to improving the operation reliability of the substation or power plant equipment, preventing misoperation, reducing the occurrence of major accidents, and making investment funds create higher economic benefits and social benefits.

Description of drawings

Fig. 1 is a schematic structural diagram of the host signal source principle of the present utility model;

Fig. 2 is the concrete structural representation of host signal source of the present utility model;

Fig. 3 is a schematic diagram of the principle structure of the hand-held detector of the present invention.

detailed description

In order to better understand the utility model, the utility model will be further described below in conjunction with the accompanying drawings and embodiments:

A portable mobile AC break-in fault detection and positioning device includes a host signal source and a hand-held detector. The host signal source is used to monitor whether there is AC break-in in the DC system, display the DC system voltage and AC components, and send data information to the Hand-held detectors: Hand-held detectors communicate and enter fault points to troubleshoot according to the received data information.

As shown in Figure 1, the host signal source includes a voltage division sampling unit, an isolation unit, an amplifier circuit unit, an AD sampling unit, an MCU processing unit, an output unit, and a data storage unit. The output unit includes a wireless output module and an LCD display module. The 50Hz AC power signal is input to the capacitor C after being divided by the resistor R1 and the resistor R2, and then input to the photoelectric isolation circuit in sequence after being sampled by the resistor R3, and then the signal is amplified by the amplifier circuit, and then sampled by the 12-bit high-precision AD chip After conversion, the data is analyzed and processed by the MCU. If an AC with an amplitude greater than 10V breaks into the DC system, it will output an alarm message, select a branch line, and store the AC signal waveform data.

The specific structural diagram of the host signal source is shown in Figure 2. Connect the sampling line of the DC system to the sampling terminal shown in Figure 2. When there is AC power entering the DC system, the voltage is divided and sampled through resistors R1 and R2. Finally, the sampling signal has AC and DC components at the same time, and then utilizes the characteristics of the capacitor to pass AC and block DC to isolate the DC component, and only the AC component passes through the capacitor C. Then the high-voltage and low-voltage parts are separated by the resistance R3 sampling and the photoelectric isolation circuit, thereby improving the safety and stability of the system and the device; the amplifying circuit unit is designed as a low-pass amplifier, which improves the hardware of the system for high-order Harmonic anti-interference ability. The amplified signal directly enters the 12-bit high-speed AD converter, converts it into a digital signal and inputs it to the CPU for processing. The CPU uses the FFT algorithm to perform Fourier transform on the sampled digital signal sequence, extracts the frequency spectrum of the 50Hz AC signal, and calculates the amplitude characteristic value of the AC signal, thereby realizing the judgment of the intrusion AC voltage, and at the same time Avoid the influence of other interfering signals. The host signal source samples and monitors the safe operation of the DC power system in real time. It can detect the instantaneous intrusion of AC within 285V, record the waveform of the intrusion AC signal within 60 milliseconds, and the warning time is less than 0.2 seconds, and send the data to the handheld detector.

The AD sampling unit uses a 12-bit high-precision AD conversion chip, and its reference voltage is 2.5V, so the resolution of the 12-bit AD conversion chip is 0.6mV. The parameters of resistor R1 and resistor R2 are both 500k/1W, capacitor C is 105/400V, that is, the capacitive reactance is 3.18k, resistor R3 is 190 ohms, and the isolation linear optocoupler of the photoelectric isolation circuit is 8 times the amplification relationship, and the amplification circuit adopts 40 times The amplifying circuit ensures that the effective value of the 285V AC signal at the AD sampling site is not greater than 2.5V after being processed by the circuit. Then, according to the ideal ratio, the effective value of the AC signal with an effective value of 0.1V at the AD sampling site is 0.877 mV. Therefore, the AC within 285V breaks into the DC system, which can be completely captured by the AD sampling chip with a resolution of 0.6mV.

The MCU processing unit selects ST's STM32 series single-chip microcomputer as the CPU. The CPU analyzes and processes the measurement data uploaded by the MCU to determine whether there is an AC intrusion into the DC power supply system. If there is an AC intrusion fault, the CPU reports the fault through the alarm circuit. The clock unit circuit provides time information for the device, and sends parameters to the handheld detector through the wireless module of the output unit. The system clock of STM32 series chips is up to 72M, and the minimum single instruction cycle is 13.9nS. The cycle of the 50Hz AC signal is 20mS, and its amplitude can be calculated by the Fourier transform method only by collecting a complete cycle signal. Each cycle collects 40 data, and the interval of each sampling data is 0.5mS. Use the sampling interval of 0.5mS to calculate and accumulate the data, so the calculation of the AC voltage amplitude can be completed within a period of 20mS, and the data waveform will be stored and processed after the alarm output, so for STM32 series chips with a system clock up to 72M For example, it is guaranteed to measure and calculate the AC signal with a period of 20mS and output an alarm within 200mS.

As shown in Figure 3, the hand-held detector includes a clamp transformer, an amplification filter circuit module, an AD sampling module, a wireless receiving module, a main processor MCU module, a display module, and an alarm output module, wherein the display module includes a liquid crystal display unit, The alarm output module includes voice prompts. First, the hand-held detector receives the data from the host signal source through the wireless receiving module, and starts the hand-held detector to detect AC intrusion into the fault point. Only one data communication between the handheld detector and the host signal source is required, and the communication is within 10 meters. After the communication is completed, there is no need to communicate and find the distance between the handheld detector and the host signal source during the process of finding the AC fault point. Unrestricted. Use the clamp transformer to detect whether there is AC signal current on the feeder, after amplification and filtering, then carry out AD sampling, and then the main processor MCU will calculate and judge whether there is an AC break-in fault, and display the current on the feeder on the display The signal current waveform, and at the same time voice output prompt information, whether there is an AC break-in fault.

The main processor MCU module of the hand-held detector selects the STM32 series single-chip microcomputer of ST Company as the CPU, detects in real time whether there is an AC signal current in the feeder of the DC power system through the clamp transformer, and then judges whether there is an AC signal current through the technology of the main processor MCU module There is an AC break-in fault.

At present, most of the equipment for the detection of AC channeling faults are sampling and fixed installation methods, which can detect and locate AC channeling faults, but can only determine the fault to a certain feeder line, because the fixed installation cannot be judged and located. specific point of failure. There are also some mobile ground fault finding instruments that treat AC intrusion faults as ordinary ground faults, and perform fault troubleshooting by injecting a low-frequency signal. However, the utility model is a non-fixed installation method, adopts the principle of non-injection signal, directly detects whether there is AC current in the system feeder through the clamp transformer, and uses the portable and mobile installation structure to move to find the fault point and locate the specific occurrence of AC channeling into the fault location.

The utility model is not limited to the above-mentioned specific implementation methods, the above-mentioned is only a preferred implementation case of the utility model, and is not intended to limit the utility model, and all those made within the spirit and principles of the utility model Any modification, equivalent replacement and improvement, etc. shall be included in the protection scope of the present utility model.

Claims (8)

1. A kind of portable mobile AC breaks into fault detection location device, it is characterized in that: comprise host signal source, hand-held detector; Described host signal source comprises voltage dividing sampling unit, isolation unit, amplifying circuit unit, AD sampling unit, MCU processing unit, data storage unit, output unit; said voltage division sampling unit includes AC signal source, resistor R1, resistor R2, resistor R3; said AC signal source frequency is 50Hz, used to generate AC signal; said isolation unit Including capacitor C, photoelectric isolation circuit; the photoelectric isolation circuit includes an isolated linear optocoupler; the isolated linear optocoupler is an 8-fold amplification relationship; the amplifying circuit unit includes a low-pass amplifier; the AC signal passes through a resistor R1, a resistor After R2 divides the voltage, it is input to capacitor C, and then input to the photoelectric isolation circuit, amplifier circuit unit, AD sampling unit, and MCU processing unit after being sampled by resistor R3; the AC signal is divided into two signals after being processed and output by the MCU processing unit , one signal is input to the storage unit for storage, and the other signal is input to the output unit; the hand-held detector includes a clamp transformer, an amplification filter circuit module, an AD sampling module, a wireless receiving module, a main processor MCU module, and a display module , alarm output module; the clamp transformer detects the AC fault point and the detected signal is sequentially input to the amplification filter circuit module, the AD sampling module, and the main processor MCU module; the hand-held detector is received by the wireless receiving module The data information sent from the host signal source is output and input to the main processor MCU module; the main processor MCU module calculates and judges whether there is AC channeling on the data information output from the wireless receiving module and the signal output from the AD sampling module Incoming fault, and the current waveform of the signal is displayed through the display module, and at the same time, whether there is an AC intrusion fault is output through the alarm output module. 2. A portable mobile AC break-in fault detection and positioning device according to claim 1, characterized in that: said AD sampling unit uses a 12-bit AD chip for sampling, and the reference voltage is 2.5V. 3. A portable mobile AC break-in fault detection and location device according to claim 1, wherein the output unit includes a wireless output module and a liquid crystal display module. 4. A portable mobile AC break-in fault detection and positioning device according to claim 1, characterized in that: the value parameter of the resistor R1 and the resistor R2 is 500k/1W, and the value parameter of the resistor R3 is 190 ohm, the value parameter of the capacitor C is 105/400V, and the amplification factor of the amplifier circuit unit is 40 times. 5. a kind of portable mobile AC according to claim 1 intrudes into fault detection and location device, it is characterized in that: what described MCU processing unit, main processor MCU module selects is the STM32 series single-chip microcomputer of ST Company as CPU; The MCU processing unit uses the FFT algorithm to perform Fourier transform on the sampled digital signal sequence. 6. A portable mobile AC break-in fault detection and location device according to claim 1, characterized in that: the display module includes a liquid crystal display; and the alarm output module includes a voice prompt. 7. A portable mobile AC break-in fault detection and positioning device according to claim 1, characterized in that: the hand-held detector receives the data information sent from the host signal source through the wireless receiving module, and the hand-held detector and the host The signal source only needs to communicate once, and the communication range of the communication is within 10 meters. The distance between the handheld detector and the host signal source is not limited during the process of finding the AC channeling fault point. 8. A portable mobile AC break-in fault detection and positioning device according to claim 1 or 5, characterized in that: the MCU processing unit and the main processor MCU module adopt STM32 series single-chip microcomputer as the CPU, and the system clock is 72M , the minimum single instruction cycle is 13.9nS; the 50Hz AC signal collects 40 data per cycle, and the interval of each sampling data is 0.5mS, and the waveform of the incoming AC signal can be recorded within 60mS, and the early warning time is less than 0.2S.