CN213602403U - Intelligent centralized low-voltage selective leakage protection device for coal preparation plant - Google Patents
Intelligent centralized low-voltage selective leakage protection device for coal preparation plant Download PDFInfo
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- CN213602403U CN213602403U CN202021924272.8U CN202021924272U CN213602403U CN 213602403 U CN213602403 U CN 213602403U CN 202021924272 U CN202021924272 U CN 202021924272U CN 213602403 U CN213602403 U CN 213602403U
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Abstract
The utility model relates to a centralized low pressure selectivity earth leakage protection device of intelligent of coal preparation plant, it is including being used for gathering transformer neutral point through high resistance ground system's zero sequence voltage and each present the signal acquisition unit of the zero sequence current of being qualified for the next round of competitions, receive zero sequence voltage and the zero sequence current of sampling and carry out data synchronization analysis to it and carry out serial communication and be used for showing the electric leakage fault with this next computer with at least one next computer of being qualified for the next round of competitions of synchronous judgement presenting the line that breaks down, record leakage time and numerical record historical record database of numerical value, zero sequence voltage, the host computer of each branch road zero sequence current, this next computer passes through optical fiber transceiver and fiber switch and ground computer interactive communication, this ground computer can real-time remote monitoring. The utility model discloses a method that the electric leakage information of each branch road of dispersion synchronous acquisition, concentrated and carry out the judgement selects out the trouble circuit, does not influence normal line operation.
Description
Technical Field
The utility model relates to a single-phase earth protection device especially indicates an intelligent centralized low pressure selectivity earth leakage protection device who is used for the ground electric substation of coal preparation factory.
Background
The leakage protection is one of three protection (overcurrent protection, leakage protection and protection grounding) for ensuring safe power supply of a coal mine, and is an important measure for preventing personal electric shock. The ground substation of the coal mine and the underground low-voltage feeder line are provided with leakage detecting protection devices with leakage locks or selective leakage detecting protection devices, and if the leakage detecting protection devices do not exist, the leakage detecting devices for automatically cutting off the leakage feeder lines need to be arranged.
The ground industrial power utilization of coal preparation plants and the like of coal mine enterprises generally adopts a three-phase three-wire system power supply system, the rated voltage is 1140V or 660V, and the neutral point of a transformer of the system is grounded through a high resistance. When electric leakage occurs, if the cable is damaged or reduced in insulation, the shell or the cable of electric equipment such as a motor and the like can be electrified, and if an operator carelessly touches an electrified body, personal electric shock casualty accidents can occur at any time; at the moment, the human body electric shock voltage is equal to the phase voltage of the system, and the electric shock current is higher than 154mA and is far larger than the safety current. When tripping protection is carried out on the current leakage protection device, misoperation often occurs, the line selection accuracy is not high, a fault power supply cannot be effectively and timely cut off, and the safety of mines and workers is threatened. And often causes the accident of large-area power failure of the feed-out wire of the substation due to the false action of electric leakage.
SUMMERY OF THE UTILITY MODEL
In view of this, the main objective of the present invention is to provide an intelligent centralized low-voltage selective leakage protection device for coal preparation plant, which has high accuracy in selecting lines and can avoid large-area power failure caused by the error tripping of normal branch due to leakage.
In order to achieve the above object, the present invention provides an intelligent centralized low-voltage selective leakage protection device for a coal preparation plant, which comprises a signal acquisition unit for acquiring zero-sequence voltage of a transformer neutral point and zero-sequence current of each feeding line, at least one lower computer for receiving the acquired zero-sequence voltage and zero-sequence current and analyzing the data of the zero-sequence voltage and zero-sequence current to judge the feeding line with a fault, and an upper computer for communicating with the lower computer and displaying historical records of leakage fault, zero-sequence voltage and zero-sequence current values, zero-sequence voltage real-time values and zero-sequence current real-time values; the lower computer is in interactive communication with the optical fiber switch and the ground computer through the optical fiber transceiver, and the ground computer can perform real-time remote monitoring.
The signal acquisition unit comprises a zero sequence voltage sampler and a zero sequence current transformer which are respectively used for acquiring zero sequence voltage and zero sequence current.
The lower computer comprises a CT/PT signal conditioning unit, an ARM operation processing unit and a relay output unit, wherein the CT/PT signal conditioning unit is sequentially connected and can convert a zero-sequence current signal and a zero-sequence voltage signal into a voltage signal which can be directly processed by an ARM, the ARM operation processing unit is used for carrying out A/D conversion on the voltage signal and processing the converted digital signal to judge a feed-out line with a fault, the relay output unit is used for controlling the relay to be attracted, the signal acquisition unit is used for directly sending the sampled zero-sequence voltage and zero-sequence current into the CT/PT signal conditioning unit, and the ARM operation processing unit is communicated with the upper computer through an RS-485 bus.
The CT/PT signal conditioning unit comprises a signal isolator, a signal filter and a signal synchronous conditioner.
Each ARM operation processing unit of the lower computer is provided with a first connecting terminal, a second connecting terminal and a third connecting terminal, each connecting terminal is an RS485 communication interface, the first connecting terminal of one ARM operation processing unit is communicated with the upper computer, the other two adjacent ARM operation processing units are connected with the first connecting terminal through the third connecting terminal, and the third connecting terminal of the last-stage ARM operation processing unit is connected with a 1/4W resistor with the precision of 0.1% of 120 ohms in series.
Each ARM operation processing unit of the lower computer is provided with a first wiring terminal, a second wiring terminal, a third wiring terminal and a fourth wiring terminal, each wiring terminal is an RS485 communication interface, the first wiring terminal of one ARM operation processing unit is communicated with the upper computer, the rest two adjacent ARM operation processing units are connected with the first wiring terminal through the fourth wiring terminal, and the fourth wiring terminal of the last-stage ARM operation processing unit is connected with a 1/4W resistor with the precision of 0.1% of 120 ohms in series.
The upper computer is a liquid crystal display.
The utility model discloses an earth leakage protection device that uses in intelligence leak hunting ground resistance protection device and the various switches in current colliery has fundamental difference, the utility model discloses a scattered formula method that carries out the judgement is gathered in the dispersion, and the exactness of route selection reaches 100%, has really realized the selectivity tripping operation, can reduce the influence of accident to the minimum. Meanwhile, due to the rapidity of action, when a human body electric shock accident occurs, a safety parameter of 30mA.s can be ensured, the human body is protected from death caused by electric shock, the power failure range can be narrowed, the accident loss is reduced, and the safety protection device is advanced and reliable.
Drawings
Fig. 1 is a schematic block diagram of the intelligent centralized low-voltage selective leakage protection device of the coal preparation plant of the present invention;
fig. 2 is a schematic block diagram of the intelligent centralized low-voltage selective earth leakage protection device of the coal preparation plant of the present invention, in which the specific structure of the lower computer is shown;
fig. 3 is a schematic block diagram of another embodiment of the intelligent centralized low-voltage selective earth leakage protection device of the coal preparation plant of the present invention.
Detailed Description
In order to facilitate a further understanding of the structure and the achieved effects of the present invention, the following detailed description of the preferred embodiments is made with reference to the accompanying drawings.
As shown in fig. 1, the utility model discloses a centralized low pressure selectivity earth leakage protection device of intelligent of coal preparation plant is including host computer 3, at least one next machine 2 that carries out the communication with host computer 3 reaches signal acquisition unit 1 of being connected with next machine 2, this signal acquisition unit 1 gathers the zero sequence voltage of transformer neutral point and the zero sequence current of each feeder line, this signal acquisition unit 1 carries the zero sequence voltage and the zero sequence current of gathering to next machine 2, this next machine 2 is handled the signal of gathering and is judged which feeder line is out of order and fault or the trunk line is out of order and is out the trip signal, show electric leakage fault, zero sequence voltage and zero sequence current electric leakage fault numerical value record, zero sequence voltage and zero sequence current on host computer 3 simultaneously. The upper computer 3 can be a liquid crystal display, and the lower computers 2 are connected in sequence.
The utility model provides a signal acquisition unit 1 is used for gathering the zero sequence voltage of transformer neutral point and each presents the zero sequence current of being qualified for the next round of competitions including zero sequence voltage sampler and zero sequence current transformer respectively. As shown in fig. 2, the utility model provides a lower computer 2 is including the CT/PT (Current Transformer/Potential Transformer, Current is mutual inductance/voltage is mutual inductance) signal synchronization regulation unit 20 that connects gradually, ARM (Advanced RISC machine, RISC microprocessor) operation processing unit 21 and relay output unit 22, zero sequence voltage and the zero sequence Current that signal acquisition unit 1 will be sampled directly send into CT/PT signal synchronization regulation unit 20, communicate through the RS-485 bus between ARM operation processing unit 21 and the host computer 3, relay output unit 22 directly outputs trip signal. The CT/PT signal synchronous conditioning unit 20, the ARM operation processing unit 21 and the relay output unit 22 are plugged on a motherboard, and the motherboard is also plugged with a power panel for supplying power to the units, and the power panel provides an external alternating current power interface. The basic task of the CT/PT signal synchronous conditioning unit 20 is to convert the analog current signal and voltage signal sampled by the zero-sequence current transformer and the zero-sequence voltage sampler into an analog voltage signal that can be directly processed by the ARM, and perform necessary signal conditioning, amplification, and the like; the ARM operation processing unit 21 is mainly responsible for A/D conversion of the analog voltage signal transmitted by the CT/PT signal conditioning unit, operation processing of the converted digital signal to judge a feed-out line with a fault, control of the relay output unit 22 and communication with the upper computer 3; the relay output unit 22 receives the signal from the ARM arithmetic processing unit 21 to control the actuation of the relay, i.e. to output a trip signal. The CT/PT signal conditioning unit 20 further includes a signal isolator 200, a signal filter 201, and a signal synchronization conditioner 202 (as shown in fig. 2) connected in sequence, and can isolate and filter signals.
The utility model discloses a low pressure selectivity earth-leakage protection device ARM arithmetic processing unit 21 has first binding post when controlling 28 branches, second binding post and third binding post, each binding post is RS485 communication interface, one of them ARM arithmetic processing unit's first binding post communicates with host computer 3, be connected with first binding post through third binding post between all the other two adjacent ARM arithmetic processing units, last ARM arithmetic processing unit's third binding post concatenates the 1/4W resistance of a 120 ohmic 0.1% precision. If the utility model discloses an earth resistance protection device ARM arithmetic processing unit 21 has first binding post when controlling 56 branches, second binding post, third binding post and fourth binding post, each binding post is RS485 communication interface, one of them ARM arithmetic processing unit's first binding post communicates with host computer 3, be connected with first binding post through fourth binding post between all the other two adjacent ARM arithmetic processing units, last ARM arithmetic processing unit's fourth binding post concatenates the 1/4W resistance of a 120 ohmic 0.1% precision.
After the zero sequence current of each branch circuit and the zero sequence voltage of the neutral line of the transformer are sampled by a zero sequence current transformer and a zero sequence voltage sampler of the neutral line which are arranged on each branch circuit, the zero sequence current and the zero sequence voltage of the neutral line of the transformer are conditioned by signals, and the conditioned zero sequence current and the conditioned zero sequence voltage are sent to an ARM operation processing unit 21 for calculation and judgment, and then are output to a relay output end element 22 for alarming. Meanwhile, real-time data are also sent into a 10.4-hour liquid crystal display through a serial port bus, corresponding software is installed on the upper computer 3, zero-sequence current and neutral zero-sequence voltage of each branch circuit are displayed in real time, the functions of data query and fault query are achieved, and meanwhile, data can be set for a CPU of an ARM operation processing unit 21 of the lower computer through the software.
As shown in fig. 3, the utility model provides an ARM arithmetic processing unit 21 passes through optical fiber transceiver 4 and optical fiber switch 5 and the interactive communication of ground computer 6, communicates through fiber interface between ARM arithmetic processing unit 21 and the optical fiber transceiver 4 and between optical fiber transceiver 4 and the optical fiber switch 5, and this optical fiber switch 5 passes through optic fibre and the communication of ground computer 6. The utility model provides an optical fiber transceiver 4, optical fiber switch 5 are mainly responsible for and carry out the communication with ground computer 6, realize remote computer's real-time demonstration and operation.
The utility model provides a ground computer 4 is mainly used for remote monitoring, and optical fiber transceiver 4 passes through giga net twine network and realizes ground computer 4's real-time remote data communication, can realize the modification of data, settlement, long-range resetting and control, historical data and fault information's inquiry.
The intelligent centralized low-voltage selective leakage protection device of the coal preparation plant adopts the zero-sequence power direction principle and the zero-sequence current group ratio-amplitude phase principle to judge the fault line; when the judgment is carried out by adopting a zero sequence power direction principle, the lower computer synchronously acquires the neutral point voltage of the transformer, namely zero sequence voltage and the zero sequence current of each feed-out line through a zero sequence voltage transformer and a current transformer, and calculates the amplitude and the phase after filtering and A/D conversion; the CPU compares the magnitude of the collected zero sequence voltage and zero sequence current with each fixed value, and compares the phase positions of the two, when the circuit is determined to have the leakage fault, the fault outlet can be accurately judged, the outlet relay is started to trip, and the leakage fault, the zero sequence voltage and the zero sequence current are displayed on the liquid crystal display screen of the computer; when the zero-sequence current group amplitude-to-phase ratio principle is adopted, the relation between the amplitude and the phase of each zero-sequence current is compared by using the real part and the imaginary part of the current phasor through the current collected by the zero-sequence current transformer, if the sum of the product of the real part and the product of the imaginary part between one branch mutual inductor current and the other two currents is less than zero, the fact that single-phase leakage happens on the branch can be judged, and the branch switch performs leakage protection action; if the sum of the products of the real part and the imaginary part between any two currents is larger than zero, it can be judged that single-phase leakage must occur on the main line, and the main switch performs leakage protection action.
When the system has no single-phase earth fault, the device is in a monitoring state, the liquid crystal screen displays the current date and time, when the zero-sequence voltage is greater than a setting value (100V), the system is indicated to generate single-phase earth, at the moment, the CPU filters, sorts and judges the acquired zero-sequence voltage data and all the zero-sequence current data, sends earth fault information (such as earth initial time, fault line number, fault accumulated time and the like) to the liquid crystal screen for display after multiple times of comprehensive analysis, and sends the judgment result to the relay for outputting and alarming.
The utility model discloses a liquid crystal display real-time display system in each ARM operation processing unit in the zero sequence voltage value and each branch zero sequence current value; once a certain branch circuit has an electric leakage fault, the liquid crystal display displays the electric leakage protection action of the certain branch circuit, and meanwhile, the fault lamp and the protection lamp can be lightened until the fault is relieved, and the system recovers to operate normally; the liquid crystal display has specific functions of resetting/closing a certain branch, modifying a setting value, modifying gain and the like.
The technical parameters of the utility model:
56 branches of a branch can be monitored simultaneously;
the grounding mode is as follows: suitable for high-resistance grounding system;
wire outlet mode: a cable or overhead line;
when the voltage of the voltage relay is more than 60V (150mA), the device gives out sound and light alarm; tripping a transformer low-voltage incoming cabinet with the voltage of more than or equal to 100V (300 mA);
when the current of the leakage current relay is more than or equal to 150mA, the resistor cabinet gives out sound and light alarm; when the current is more than or equal to 300mA, the transformer low-voltage incoming cabinet trips;
zero-sequence current input range: 0-1000 mA;
zero-sequence voltage input range: 0-999V;
alarm output contact capacity: AC 250V 5A; DC 12V 1A;
rated operating voltage: AC/DC 220V +/-20%;
rated operating frequency: 50 Hz;
the power consumption of the whole machine is as follows: < 25W;
a communication interface: RS232/485, Baud rate 9600 bps.
The utility model adopts a distributed method of scattered collection of leakage information, centralized discrimination, centralized management and independent control, the accuracy of line selection reaches 100 percent, thereby really realizing selective tripping and reducing the influence of accidents to the minimum; and the device also monitors the neutral line of the transformer, and can perform sound-light alarm when reaching an alarm value, thereby performing double monitoring on the branch line and the neutral line. Meanwhile, due to the rapidity of action, when a personal electric shock accident occurs, the safety parameter of 30mAs can be guaranteed, the personal electric shock cannot be caused to die, the power failure range can be narrowed, the accident loss is reduced, meanwhile, a fault line is convenient to find, and the safety protection device is advanced and reliable. The grounding line selection device can accurately and rapidly select a grounding line or a bus when the system is in single-phase grounding. The intelligent monitoring system is simple and convenient to use, does not need maintenance, can transmit related information to a superior monitoring system through a communication interface according to user requirements, and is suitable for an unattended transformer substation.
The utility model adopts the ARM signal processing technology which has the characteristics of powerful function, high processing speed, strong anti-interference capability and the like, completely meets the severe environment of a coal preparation plant, and explores a new technical approach for developing industrial control products under the environment; the developed zero sequence current transformer adopts a novel material as an iron core, the parameter design is reasonable, the secondary signal has small distortion and strong load capacity in the transmission process of a longer distance, and the zero sequence current transformer is an important device for ensuring the correct line selection of a system and can be popularized as an independent product; the zero sequence voltage acquisition in the utility model is realized by a neutral point current/voltage conversion method, the wiring is simple, the hardware cost is low, no influence is generated on a power supply system, and the method is safe and reliable; the protection range of the utility model is 56 outgoing line loops, which completely meets the capacity requirement of the low-voltage power supply system; the utility model adopts VB programming as the LCD software of the upper computer, has friendly interface, convenient operation and password protection, and can ensure the operation safety; the ARM program is compiled by mixing assembly language and C language, so that the sampling rapidity is guaranteed, and the strong operation judgment capability is realized; the utility model discloses an independent synchronous analog quantity signal acquisition mode of subregion has successfully solved multichannel, high-speed synchronous acquisition in-process, and the operation speed is difficult to satisfy the problem of earth leakage protection action time requirement.
The utility model provides a zero sequence voltage transformer and ARM arithmetic processing unit and relay output unit are the product of selling on the market, do not do here and describe repeatedly.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention.
Claims (7)
1. An intelligent centralized low-voltage selective leakage protection device for a coal preparation plant is characterized by comprising a signal acquisition unit, at least one lower computer and an upper computer, wherein the signal acquisition unit is used for acquiring zero-sequence voltage of a neutral point of a transformer and zero-sequence current of each feed-out line; the lower computer is in interactive communication with the optical fiber switch and the ground computer through the optical fiber transceiver, and the ground computer can perform real-time remote monitoring.
2. The intelligent centralized low-voltage selective leakage protection device of a coal preparation plant as claimed in claim 1, wherein said signal acquisition unit comprises a zero sequence voltage sampler and a zero sequence current transformer for acquiring zero sequence voltage and zero sequence current, respectively.
3. The intelligent centralized low-voltage selective leakage protection device of claim 1, wherein the lower computer comprises a CT/PT signal conditioning unit capable of converting a zero-sequence current signal and a zero-sequence voltage signal into a voltage signal for direct processing by an ARM, an ARM arithmetic processing unit for performing a/D conversion on the voltage signal and processing the converted digital signal to determine a faulty feed-out line, and a relay output unit for controlling the relay to be pulled in, the signal acquisition unit directly sends the sampled zero-sequence voltage and zero-sequence current to the CT/PT signal conditioning unit, and the ARM arithmetic processing unit and the upper computer communicate with each other through an RS-485 bus.
4. The intelligent centralized low-voltage selective leakage protection device of a coal preparation plant as claimed in claim 3, wherein said CT/PT signal conditioning unit comprises a signal isolator, a signal filter and a signal synchronous conditioner.
5. The intelligent centralized low-voltage selective leakage protection device of the coal preparation plant as claimed in claim 3, wherein each of the ARM operation processing units of the lower computers has a first connection terminal, a second connection terminal and a third connection terminal, each connection terminal is an RS485 communication interface, the first connection terminal of one of the ARM operation processing units communicates with the upper computer, the other two adjacent ARM operation processing units are connected with the first connection terminal through the third connection terminal, and the third connection terminal of the last ARM operation processing unit is connected in series with a 1/4W resistor with 0.1% precision of 120 ohms.
6. The intelligent centralized low-voltage selective leakage protection device of the coal preparation plant as claimed in claim 3, wherein each of the ARM operation processing units of the lower computers has a first connection terminal, a second connection terminal, a third connection terminal and a fourth connection terminal, each connection terminal is an RS485 communication interface, the first connection terminal of one of the ARM operation processing units communicates with the upper computer, the other two adjacent ARM operation processing units are connected with the first connection terminal through the fourth connection terminal, and the fourth connection terminal of the last ARM operation processing unit is connected in series with a 1/4W resistor with a precision of 0.1% of 120 ohms.
7. The intelligent centralized low-voltage selective leakage protection device of a coal preparation plant as claimed in claim 1, wherein said upper computer is a liquid crystal display.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202021924272.8U CN213602403U (en) | 2020-09-03 | 2020-09-03 | Intelligent centralized low-voltage selective leakage protection device for coal preparation plant |
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| CN202021924272.8U CN213602403U (en) | 2020-09-03 | 2020-09-03 | Intelligent centralized low-voltage selective leakage protection device for coal preparation plant |
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| CN213602403U true CN213602403U (en) | 2021-07-02 |
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| CN202021924272.8U Active CN213602403U (en) | 2020-09-03 | 2020-09-03 | Intelligent centralized low-voltage selective leakage protection device for coal preparation plant |
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