CN110061471A - A kind of method for detecting short circuit of long range electric current - Google Patents

Abstract

The invention discloses a short-circuit detection method for long-distance current, which is characterized by comprising a power supply module, an acquisition module, a central processing module, a mathematical model library, and a man-machine interface, the output end of the power supply module, the output end of the acquisition module, the mathematical The output end of the model library is respectively connected with the input end of the central processing module, and the central processing module and the man-machine interface are connected bidirectionally. The rate of change of the current in the power grid is quickly collected and processed through the high-speed processing single chip microcomputer, which solves the problem of the traditional overcurrent protection with low sensitivity, The problem of long action time.

Description

A short-circuit detection method for long-distance current

technical field

The invention relates to a short-circuit detection method for long-distance current.

Background technique

The problem of electricity safety restricts the rapid development of productive forces, and it is particularly prominent to solve the problem of electricity safety, especially the problem of safe production in coal mines. The continuous introduction of new materials and new devices has laid the foundation for the development of new electrical equipment and the solution of electricity safety issues. However, the development of new equipment requires the support of new technologies. From the perspective of the development trend of safe electricity consumption, new theories are also needed to solve the current electricity safety protection problems. The main content of this project is to study a new electricity safety protection theory to make up for the deficiencies of the existing protection technology.

The existing technology in China does not have a very effective detection and protection measure for the overcurrent fault with long power supply distance and large line impedance. It is very necessary to improve the safety of power supply to develop an overcurrent detection technology that is less affected by line parameters, sensitive to action, and reliable. It is very necessary to improve the safety of power supply. The existing short-circuit protection technology has special requirements. There are great limitations in performance, and the existing technology cannot fully meet the safety production requirements of modern mines. It is of great significance to study new short-circuit detection technology and safety protection technology.

The existing short-circuit protection detection technology at home and abroad can be roughly divided into the following main methods:

(1) Overcurrent protection based on the detection of short-circuit current. This overcurrent protection method is set according to the principle of avoiding the maximum starting current of the motor. When the power supply line is long and the end of the line is short-circuited, the short-circuit current is very small and the protection Sensitivity is difficult to achieve.

(2) Overcurrent protection based on the principle of phase sensitivity has been researched at home and abroad, and it is relatively mature. Although the problem of protection sensitivity has been solved, this technology can only protect three-phase short-circuit, and two-phase short-circuit protection does not operate.

(3) The overcurrent protection based on the carrier frequency principle is widely used in the comprehensive protection device for coal electric drills in coal mines in China. However, this kind of protection has strict requirements on line parameters (cable cross-sectional area, length and transformer impedance, etc.), and the line parameters are out of range and refuse to move, and the reliability is poor.

For example, the publication number is CN107807585A "A Power Equipment Monitoring System", the system includes a DC/DC adaptive power supply module, an environmental data acquisition module, a data detection module, a central control module, a power distribution protection module, an overload protection module, and a module alarm. The system still uses the traditional method to monitor and operate the short-circuit current, the structure is also more complicated, and the processing speed of the module is relatively slow.

SUMMARY OF THE INVENTION

In order to solve the above technical problems, the present invention provides a short-circuit detection method for long-distance current.

The present invention is achieved through the following technical solutions.

A short-circuit detection method for long-distance current provided by the present invention is characterized in that: the current rate-of-change short-circuit detection method includes a power supply module, an acquisition module, a central processing module, a mathematical model library, a display module, and an operation platform, and the power supply The output end of the module, the output end of the acquisition module, and the output end of the mathematical model library are respectively connected with the input end of the central processing module, and the central processing module is respectively connected with the display module and the operation platform in two directions.

The power supply module is a 220V DC power supply, which provides corresponding voltages for each electronic device in the central processing module.

The acquisition module is a module composed of 89C52 single-chip microcomputer and LPC2132 chip, receives the current from the power grid in real time, and outputs different control signals to the central processing module according to the current change rate.

The mathematical model library stores the mathematical model of the circuit fault system and its current waveform.

The central processing module receives the signal from the acquisition module, retrieves the corresponding mathematical model of the circuit fault system from the mathematical model library, and feeds the result back to the man-machine interface.

The central processing module can directly perform the power grid circuit power-off operation according to the retrieved mathematical model of the circuit fault system.

The central processing module has a fault memory function, which can memorize the latest five fault information.

The display and display module displays the circuit fault information fed back by the central processing module in real time.

The operating platform issues control instructions to the central processing module.

The beneficial effect of the invention is that the change rate of the current in the power grid is quickly collected and processed by the high-speed processing single chip computer, and the problems of low sensitivity and long operation time of the traditional overcurrent protection are solved.

Description of drawings

FIG. 1 is a system structure diagram of the present invention.

Detailed ways

The technical solutions of the present invention are further described below, but the claimed scope is not limited to the description.

As shown in FIG. 1 is an embodiment of the present invention: a short-circuit detection method for long-distance current, the current rate of change short-circuit detection method includes a power supply module, an acquisition module, a central processing module, a mathematical model library, a display module, The operation platform, the output end of the power supply module, the output end of the acquisition module, and the output end of the mathematical model library are respectively connected with the input end of the central processing module, and the central processing module is respectively connected with the display module and the operation platform in both directions.

The power supply module is a 220V DC power supply, which provides corresponding voltage for each electronic device in the central processing module to ensure the normal operation of each device.

The acquisition module is a module composed of 89C52 single-chip microcomputer and LPC2132 chip. Compared with the traditional 51 single-chip microcomputer, the 89C52 single-chip microcomputer has a more flexible CPU and can be more flexibly linked with the LPC2132 control chip. The LPC2132 is a 128-bit wide memory interface and unique. The chip of the acceleration structure can process the current rate of change information received in real time at the maximum clock rate and output different control signals to the central processing module.

The mathematical model library stores a large number of experimentally obtained mathematical models of circuit fault systems and their current waveforms.

The central processing module receives the signal from the acquisition module, retrieves the corresponding mathematical model of the circuit fault system from the mathematical model library, and feeds the result back to the man-machine interface. At the same time, the central processing module will judge whether to cut off the power grid directly according to the comparison result. In the operation of the circuit, when the central processing module directly performs the power-off operation, the short-circuit protection action time does not exceed 5 milliseconds, and the effective distance can reach more than 300 meters; at the same time, the latest five fault information can be recorded, including the fault time, the fault occurred. Power grid area, fault type, and can be queried from the HMI.

The display module and the operation platform, the display module displays the circuit fault information fed back by the central processing module in real time, such as the peak current, the current change rate, the waveform diagram within a period of time when the current is short-circuited, etc. The processing module issues control commands and makes corresponding strategies according to different circuit fault conditions.

Claims (9)

1. a kind of method for detecting short circuit of long range electric current, it is characterised in that: the short circuit current detection method includes power supply mould Block, acquisition module, central processing module, Mathematic Model Library, display module, operating platform, the power module outlet, acquisition Module output end, Mathematic Model Library output end are connect with central processing module input terminal respectively, central processing module respectively with it is aobvious Show that module, operating platform are bi-directionally connected respectively.

2. a kind of method for detecting short circuit of long range electric current as described in claim 1, it is characterised in that: the power module is 220V DC power supply provides relevant voltage for electronic equipment each in central processing module.

3. a kind of method for detecting short circuit of long range electric current as described in claim 1, it is characterised in that: the acquisition module is The module of 89C52 single-chip microcontroller and LPC2132 chip composition, the electric current that real-time reception power grid transmits, according to the feelings of current changing rate Condition exports different control signals to central processing module.

4. a kind of method for detecting short circuit of long range electric current as described in claim 1, it is characterised in that: the Mathematic Model Library Store fault system mathematic model and its current waveform.

5. a kind of method for detecting short circuit of long range electric current as described in claim 1, it is characterised in that: the central processing mould Block receives the signal that acquisition module transmits, and corresponding fault system mathematic model is retrieved from Mathematic Model Library, will be tied Fruit feeds back to man-machine interface.

6. a kind of method for detecting short circuit of long range electric current as claimed in claim 5, it is characterised in that: the central processing mould Block can directly execute mains-power circuit power operation according to the fault system mathematic model retrieved.

7. a kind of method for detecting short circuit of long range electric current as described in claim 1, it is characterised in that: the central processing mould Block has the function of trouble and managing, can remember nearest five fault messages.

8. a kind of method for detecting short circuit of long range electric current as described in claim 1, it is characterised in that: the display shows mould Block real-time display goes out the fault information of central processing module feedback.

9. a kind of method for detecting short circuit of long range electric current as described in claim 1, it is characterised in that: the operating platform pair Central processing module issues control instruction.