CN107543982A - Towards the non-intruding Fault Identification device of low-voltage customer - Google Patents

Abstract

The invention discloses a low-voltage user-oriented non-invasive fault identification device, which comprises a current transmitter unit, a multifunctional data acquisition unit, an industrial computer unit, a power supply system unit and a data transmission unit. The current transmitter unit converts the high-current signal of the user's home cable into a weak voltage signal, and the multi-function data acquisition unit collects the voltage signal and sends it to the main board program of the industrial computer for data processing to complete real-time signal monitoring, fault waveform recording and display, The fault type judgment and data communication function, and the communication function with the main station adopt GPRS technology to realize the real-time monitoring of the main station. The non-intrusive fault identification device has the characteristics of simple structure, low construction cost, and easy maintenance. It can realize the function of short-circuit accident monitoring and has obvious technical advantages. The focus of work is to overcome the technical problems of short-circuit current detection and positioning under non-intrusive fault identification.

Description

Non-intrusive fault identification device for low-voltage users

technical field

The invention relates to the field of electricity safety monitoring, in particular to a non-invasive fault identification device for low-voltage users.

Background technique

The monitoring methods of power load status and safety accidents can be divided into two categories: intrusive and non-intrusive. At present, the non-intrusive monitoring framework is mainly applied to the monitoring and decomposition of electric loads, and there is no application case in the monitoring of electricity safety. Non-intrusive load monitoring (NILM) only needs to install a monitoring device at the entrance of the power supply, and through the modeling of the monitored power grid and supporting advanced algorithms, online monitoring of the operation status of the entire power grid can be realized .

At present, there are few reports at home and abroad that are used for user hidden danger investigation and accident analysis automation system. Non-intrusive fault identification device is a new technical field. There is no special software in my country that can realize the functions of user power accident action protection and safety hazard investigation. , but there are many related theories, especially the rapid development of distribution line safety monitoring technology provides a lot of technical basis for power safety. The distribution network safety monitoring and early warning system already has the function of monitoring load data, harmonic data, insulation status and other real-time data of the line, and automatically saving the monitoring data. It can also compare monitoring and setting data, and automatically provide early warning or alarm information. Line maintenance personnel carry out line maintenance according to data records, effectively avoiding safety accidents caused by line failures. In addition, the fault diagnosis technology and power safety management technology of power equipment such as transformers and motors also provide a rich theoretical basis for the investigation of power safety hazards and accident action analysis. Transformer online monitoring system, intelligent power monitoring equipment, fault monitoring and diagnosis system, etc. are constantly developing.

Therefore, the non-intrusive fault identification device can be widely used in places where it is difficult to install distributed measurement and control devices. It will have a wide range of applications in the future and a broad market prospect.

Contents of the invention

The technical problem to be solved by the present invention is to provide a low-voltage user-oriented non-invasive fault identification device with simple structure, low construction cost and easy maintenance.

In order to solve the above technical problems, the present invention includes

The current transmitter unit is used to convert the large current signal of the user's home cable into a weak voltage signal, and provide the original current sampling signal for the analysis program of the device;

The multi-function data acquisition unit is used to collect weak voltage signals and convert weak voltage signals into binary data. Using the high-speed acquisition function of its own core unit, digital trigger and synchronous bus are used to store the converted binary data into the industrial computer disk. , to provide an undistorted data source for the industrial computer unit;

The industrial computer unit is used to run the fault detection and positioning program, read the data signal obtained by the multi-function data acquisition unit from the industrial computer disk, and perform analysis and calculation to complete real-time signal monitoring, fault waveform recording and display, fault type judgment and Data communication function;

a data transmission unit for transmitting the analysis and calculation results of the fault detection and location program to the grid main station; and

The power system unit is used to provide power to the various units of the device.

The beneficial effects of the present invention are:

(1) The intrusive fault identification method needs to install a large number of detection equipment and communication lines inside the user grid. For example, installing electrical quantity acquisition sensors and communication interfaces on each branch to be monitored will consume a lot of manpower and material resources. Purchase, install and maintain these devices. Non-intrusive measurement only needs to install a monitoring device at the main incoming line, mainly relying on advanced algorithms to identify accident protection actions inside the user's power grid, greatly reducing hardware costs and maintenance.

(2) The non-intrusive fault identification device can be installed without interrupting the power supply of the equipment, which is easy to be accepted by users.

Description of drawings

Fig. 1 is a functional block diagram of the low-voltage user-oriented non-intrusive fault identification device of the present invention.

detailed description

Below in conjunction with accompanying drawing and specific embodiment the present invention will be described in further detail:

Referring to Fig. 1, the non-intrusive fault identification device for low-voltage users of the present invention includes a current transmitter unit, a multifunctional data acquisition unit, an industrial computer unit (embedded industrial motherboard unit), a power supply system unit, and a data transmission unit and related interface circuits. The device of the present invention is mainly deployed at the general gate of the low-voltage circuit. In addition to being able to identify the internal fault area and fault type of the low-voltage circuit, it also has a wave recording function, a real-time current waveform display function and a data storage function, which enriches the functions of low-voltage power distribution terminal products. .

The device internally adopts a high-efficiency switching power supply scheme to realize AC~DC, which can reduce its own power consumption to the greatest extent. The current transmitter unit can collect 0-2500A current, rated output 5V voltage signal, and the response time is less than 20us. The multi-function data acquisition unit provides analog input, analog output, digital I/O and counter/timer I/O usage. The selected model of industrial motherboard is MITX-6936, based on Intel NM10 chipset, onboard Intel Atom N2800/D2500/D2550 processor; 1 SO-DIMM slot supports DDR3 800/1066MHz, maximum support 4GB; VGA/DVI-D/LVDS , support independent dual display; 2 Gigabit Ethernet; 2x SATAII/6x USB2.0/2x COM/2x PCI/1x LPC. Quectel's M72D is used as the data transmission unit, with a real-time operating system as the software support platform, a large memory, and a TCP/IP protocol stack embedded with independent intellectual property rights. Provide users with a high-speed, stable and reliable virtual private network with data terminals always online and multiple protocol conversions. For users of network traffic control, the product supports the functions of voice, SMS, and data triggering online and automatic disconnection after timeout. At the same time, it also supports dual data center backup, and multiple data centers receive data synchronously.

The non-intrusive fault identification device is composed of a current transmitter unit, a multifunctional data acquisition function unit, an industrial motherboard unit, a power supply system unit, a data transmission unit and related interface circuits. The current transmitter unit converts the high current signal of the user's home cable into a weak voltage signal. The multi-function data acquisition card collects the voltage signal and sends it to the main board program of the industrial computer for data processing to complete real-time signal monitoring, fault waveform recording and display, The fault type judgment and data communication function, and the communication function with the main station adopt GPRS technology to realize the real-time monitoring of the main station.

Each component unit of the low-voltage user-oriented non-intrusive fault identification device of the present invention is now described in detail:

(1) The current transmitter unit is composed of signal input, signal output and working power supply. The clamp-type current transmitter is selected in the design. The advantage is the detachable structure, which can pass through the power distribution without power failure or disconnection. The AC busbar in the room converts the AC current signal into a DC voltage signal. It is used to measure DC, AC, pulse current and other arbitrary waveform currents, and transmit weak voltage signals to the data acquisition card of PCI interface, so as to provide original current sampling signals for the analysis program of the device. Selected model: JLK-23/2000; installation method: fixed with flat screws.

(2) The multi-function data acquisition unit selects the data acquisition card with PCI interface, the selected model is NI PCI-6010, 16 bits, sampling rate 200kS/s, 16-way analog input multi-function DAQ. The NI PCI-6010 is a low-cost multifunction I/O data acquisition board that provides analog input, analog output, digital I/O, and counter/timer I/O. Using the 37-pin D-Sub connector, you can connect the NI PCI-6010 to many available D-Sub components. This unit converts the signal of the current transmission unit into a binary number, uses the high-speed acquisition function of its own core unit, and uses a digital trigger and synchronous bus (RTSI) to store the converted binary data into the disk of the industrial computer and send it to the industrial computer unit. Provides an undistorted data source.

(3) The selection of industrial computer unit is based on Intel NM10 chipset, with onboard Intel Atom N2800/D2500/D2550 processor; 1 SO-DIMM slot supports DDR3 800/1066MHz and supports up to 4GB; VGA/DVI-D/LVDS, Support independent dual display; 2 Gigabit Ethernet; 2x SATAII/6x USB2.0/2x COM/2x PCI/1x LPC. The board has various interfaces, powerful functions, flexible configuration of peripherals, and excellent on-site anti-interference ability. The computing speed of the CPU can reach 1066MHz, which can easily handle integer floating-point calculations and provide strong support for the realization of non-intrusive algorithms. Run the fault detection and positioning program, read the data signal obtained by the data acquisition card from the industrial computer disk, and perform analysis and calculation.

(4) The power supply system unit includes two parts: 220VAC～5VDC power supply circuit and 220VAC～15VDC power supply circuit. These two parts both adopt the switching power supply scheme, which has the advantages of low power consumption, high efficiency, small size and light weight compared with the power frequency transformer and the traditional LDO scheme.

The 220VAC～5VDC power supply circuit adopts UC3842 non-isolation scheme, the circuit is simple, and the AC-DC conversion from AC80～260V input to DC5V can be realized by using more than a dozen electronic components. Due to the adoption of advanced dynamic self-supply (DSS), the operating voltage of UC3842 can be drawn directly from the drain, thus eliminating the need for auxiliary coils, simplifying the circuit, reducing the volume occupied by the transformer, and reducing the cost.

(5) The data transmission unit mainly transmits the analysis and calculation results of the fault detection and positioning program to the main station of the power grid, and is mainly composed of a communication module circuit and a sim card circuit. The communication module adopts the Quectel M72 module, and the real-time operating system is used as the software support platform , large memory, embedded TCP/IP protocol stack with independent intellectual property rights. Provide users with a high-speed, stable and reliable virtual private network with data terminals always online and multiple protocol conversions. For users of network traffic control, the product supports the functions of voice, SMS, and data triggering online and automatic disconnection after timeout. At the same time, it also supports dual data center backup, and multiple data centers receive data synchronously.

In summary, the content of the present invention is not limited to the above-mentioned embodiments, and those skilled in the art can propose other embodiments within the technical guidance of the present invention, but these embodiments are all included in the scope of the present invention. within range.

Claims (1)

1. A non-intrusive fault identification device for low-voltage users, characterized in that: comprising The current transmitter unit is used to convert the large current signal of the user's home cable into a weak voltage signal, and provide the original current sampling signal for the analysis program of the device; The multi-function data acquisition unit is used to collect weak voltage signals and convert weak voltage signals into binary data. Using the high-speed acquisition function of its own core unit, digital trigger and synchronous bus are used to store the converted binary data into the industrial computer disk. , to provide an undistorted data source for the industrial computer unit; The industrial computer unit is used to run the fault detection and positioning program, read the data signal obtained by the multi-function data acquisition unit from the industrial computer disk, and perform analysis and calculation to complete real-time signal monitoring, fault waveform recording and display, fault type judgment and Data communication function; a data transmission unit for transmitting the analysis and calculation results of the fault detection and location program to the grid main station; and The power system unit is used to provide power to the various units of the device.