Mining flame-proof and intrinsically safe high-voltage combined vacuum power distribution device and power distribution method

Abstract

The invention belongs to the technical field of mining area electrical explosion prevention, and particularly relates to a mining flame-proof and intrinsically safe high-voltage combined vacuum power distribution device and method, and the device comprises a power distribution loop compartment, a bus compartment, a centralized control compartment, and a secondary independent wiring compartment. Wherein the power distribution loop compartment is an independent explosion-proof compartment, the bus compartment adopts an upper-layer and lower-layer reserved door structure and corresponds to the power distribution loop compartment, and the centralized control compartment is connected with a circuit breaker of the power distribution loop compartment and a mutual inductor of the bus compartment through a control cable, receives various sensor signals and sends out control instructions; the centralized control compartment is used for completing power distribution control, voltage, current and temperature signal acquisition, network communication, operation display and power supply control. The device is reasonable in layout, installation, maintenance and overhaul of each compartment are facilitated, the safety of the device is enhanced, the maintenance workload and the maintenance cost of the equipment are reduced, and an operator can conveniently know the operation state of the equipment in time and find potential faults in advance.

Description

Technical Field

[0001] The invention relates to the technical field of electrical explosion-proof in mining areas, and in particular to a flameproof and intrinsically safe high-voltage combined vacuum power distribution device for mining. Background Art

[0002] The explosion-proof and intrinsically safe high-voltage combined vacuum distribution device for mining is a power distribution device used in special environments such as underground coal mines. It integrates explosion-proof and intrinsically safe characteristics and is mainly used to control, protect and distribute electric energy to high-voltage circuits in underground coal mines to ensure that various electrical equipment in the mines can operate safely and stably. The explosion-proof function is used to prevent arcs and sparks generated inside the equipment from causing explosions in external explosive environments; the intrinsic safety characteristics ensure that in normal operation or specified fault conditions, the generated electric sparks or thermal effects will not ignite the surrounding explosive gas mixture.

[0003] The main structures of the explosion-proof and intrinsically safe high-voltage combined vacuum distribution device for mining include casing, circuit breaker, protection device, control power supply, etc. The casing needs to be able to withstand a certain pressure without leakage, structural damage and permanent deformation that affects the explosion-proof performance. The circuit breaker is used to connect and disconnect the circuit. Vacuum circuit breakers are generally used to avoid arc damage to the equipment. The protection functions of the protection device, including overcurrent protection, short-circuit protection, insulation monitoring protection, leakage protection, etc., need to be able to detect faults in the circuit in time and take corresponding protection measures. Control circuit: used to control the closing and opening operations of the circuit breaker, and to monitor the operating status of the circuit. The isolation mechanism is responsible for the electric closing and opening functions,

[0004] The current vacuum power distribution device is large in size, which is not conducive to installation in the limited space underground, and often does not have an independent explosion-proof compartment. In the environment where there are flammable and explosive gases such as gas underground, once a fault occurs inside the power distribution device and sparks or arcs are generated, it is easy to cause an explosion accident, and the fault area cannot be effectively isolated, posing a threat to the safety of the mine. In addition, it is difficult to achieve real-time detection, transmission and corresponding control of signals such as voltage, current, and temperature, and it is difficult to detect potential faults in time, which increases the probability of sudden equipment failures and is not conducive to the intelligent management and remote control of the mine power supply system. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a mine-use explosion-proof and intrinsically safe high-voltage combined vacuum power distribution device.

[0006] The complete technical solution of the present invention includes:

[0007] A mine-use explosion-proof and intrinsically safe high-voltage combined vacuum power distribution device, comprising a power distribution circuit compartment, a busbar compartment, a centralized control compartment, and a secondary independent wiring compartment;

[0008] The power distribution circuit compartment is an independent flameproof compartment, and the busbar compartment adopts a two-layer reserved door structure, corresponding to the power distribution circuit compartment. The centralized control compartment is connected to the circuit breaker of the power distribution circuit compartment and the mutual inductor of the busbar compartment through control cables, receiving various sensor signals and issuing control instructions;

[0009] The centralized control compartment is used to complete power distribution control, voltage, current, temperature signal acquisition, network communication, operation display, and control power supply.

[0010] Furthermore, a trolley-type circuit breaker and a camera are placed in the power distribution circuit compartment.

[0011] Furthermore, the busbar compartment is provided with a busbar, a main circuit terminal, a grounding switch, a load cable, a varistor, a current transformer, a three-phase five-column transformer, and a PT transformer.

[0012] Furthermore, the centralized control compartment is equipped with integrated protection devices for each unit, PLC, circuit breaker trolley controller, industrial switch, 15.6-inch touch screen, miniature circuit breaker, relay, switching power supply, intrinsically safe power supply, and intrinsically safe keyboard.

[0013] Furthermore, the secondary wiring compartment reserves 20 A1 bell mouths and 4 A3 bell mouths for the outside, and its internal wiring connects the centralized control compartment with the external control lines and communication lines, and the lines are led out through the bell mouths to connect with other automation equipment.

[0014] Furthermore, when the vacuum distribution device is supplying power, high voltage electricity is distributed to the main circuit terminals of each distribution circuit compartment through the busbar in the busbar compartment, the trolley-type circuit breaker is in the working position and closed, and the electric energy is transmitted to the load; the current transformer collects the current signal in the main circuit, the three-phase voltage transformer collects the voltage signal, and the wireless temperature sensor monitors the temperature signal, and transmits it to the comprehensive protection device in the centralized control compartment for monitoring and analysis.

[0015] Furthermore, the vacuum power distribution device performs overcurrent protection, short-circuit protection, insulation monitoring, grounding (leakage) protection, voltage protection, phase balance, wind power interlocking, fault recording and anti-overtripping according to current and voltage signals.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. This device adopts a combined power distribution structure, and the upper and lower unit design makes the layout of the entire device reasonable. This structure is convenient for the installation, maintenance and overhaul of each compartment. The power distribution circuit compartment and the secondary wiring compartment are independent flameproof compartments, which enhances the safety of the device. In environments such as underground where flammable and explosive gases may exist, the flameproof compartment can effectively prevent the explosion caused by internal faults from spreading outward, protecting the safety of surrounding equipment and personnel.

[0018] 2. The trolley-type circuit breaker adopts a sealed pole type, which reduces the equipment maintenance workload and maintenance cost. Its high segmentation capacity can quickly cut off the circuit when a fault occurs, effectively protecting downstream equipment from damage by fault current. The circuit breaker is equipped with an electric chassis, and the combination of motor drive and manual drive facilitates the conversion of the circuit breaker between the working position and the maintenance test position. And when the electric trolley drive motor is blocked, it can brake in time and reverse drive the motor to release the stuck state, which improves the reliability and service life of the equipment.

[0019] 3. Equipped with a complete voltage and current signal measurement system, it provides accurate electrical signals for metering and protection, and can display the operating parameters of each circuit in real time, such as voltage, current, insulation monitoring, circuit breaker opening and closing status, fault records, temperature, etc., so that operators can understand the equipment operation status in time and discover potential faults in advance.

[0020] 4. The video signal can be uploaded to the ground control center through the underground network to realize the visualization of remote operation. The reserved high-voltage cable connector installation interface and secondary horn mouth meet the needs of automated wiring, facilitate connection with other automated equipment, realize data upload, remote meter reading and other functions, and help improve the level of automated management of mine power supply systems.

[0021] 5. The present invention aims at the complex and changeable load conditions of electrical equipment in mines, where intermittent overloads often occur. A reasonable inverse time algorithm is adopted, which can calculate the overload energy according to the ratio of the overload current to the rated current and the duration of the overload. By calculating the overload energy to simulate the heat accumulation process inside the equipment, the normal load fluctuation and the real overload fault can be effectively distinguished. The sensitivity to environmental factors is low, and it can well adapt to the complex load change scenarios in mines. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the appearance diagram of the mine-use explosion-proof and intrinsically safe high-voltage combined vacuum distribution device of the present invention.

[0023] Figure 2 This is a control interface diagram of the mine-use explosion-proof and intrinsically safe high-voltage combined vacuum power distribution device of the present invention. DETAILED DESCRIPTION

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only for illustration and are not intended to limit the present application.

[0025] The following is a detailed description of the mine-use explosion-proof and intrinsically safe high-voltage combined vacuum power distribution device disclosed in the present invention.

[0026] The vacuum power distribution device of the present invention has the following appearance: Figure 1 As shown, a combined power distribution structure is adopted with an upper and lower unit design, including a power distribution circuit compartment, a busbar compartment, a centralized control compartment, and a secondary independent wiring compartment.

[0027] The power distribution circuit compartment is an independent explosion-proof compartment, which is used to place trolley-type circuit breakers and cameras. The front door of the chamber is equipped with a 4.3-inch LCD screen, a high-voltage live display, parameter setting buttons, electric opening, electric closing, manual opening, manual closing, leakage test buttons, a front door locking handle, and an observation window. The power distribution circuit compartment is electrically connected to the centralized control compartment through internal wiring to achieve signal transmission and control command reception. The observation window can view the circuit breaker opening and closing status and energy storage status, etc. Various buttons can perform electric or manual opening and closing operations on the circuit breaker and parameter setting, etc. The LCD screen can display the operating parameters of each circuit, such as voltage, current, insulation monitoring, circuit breaker opening and closing status, fault records, etc.

[0028] The busbar compartment adopts an upper and lower reserved door structure, corresponding to the distribution circuit compartment, and is used to place busbars, main circuit terminals, grounding switches, load cables, varistors, current transformers, three-phase five-column transformers, PT transformers, etc.

[0029] The busbar is connected to the main circuit terminals of each distribution circuit compartment to achieve the distribution and transmission of electric energy. The grounding switch is electrically connected to the grounding device on the output cable side of the distribution circuit compartment, and a grounding loop can be formed during maintenance. Current transformers, three-phase five-column transformers, PT transformers, etc. are connected to the integrated protection devices in the centralized control compartment through cables to provide them with electrical signals required for measurement and protection.

[0030] The busbar compartment provides the main line for power transmission for the entire power distribution system, and also realizes functions such as grounding protection, voltage and current signal collection, etc. The PT transformer provides voltage signals for measurement and protection to ensure the accuracy of fault judgment.

[0031] The centralized control compartment is equipped with integrated protection devices for each unit, PLC, circuit breaker trolley controller, industrial switch, 15.6-inch touch screen, intrinsically safe keyboard, miniature circuit breaker, relay, switching power supply, intrinsically safe power supply, intrinsically safe keyboard, etc. The centralized control compartment is connected to the circuit breaker in the distribution circuit compartment, the transformer in the bus compartment and other equipment through control cables, receives various sensor signals and issues control instructions. The integrated protection device receives signals from the current transformer and voltage transformer for fault judgment and protection action, and can control the movement of the circuit breaker trolley through the circuit breaker trolley controller. It is connected to the secondary wiring compartment through a reserved interface to realize the lead-out of the control line and communication line and the connection with external equipment.

[0032] The centralized control compartment realizes functions such as power distribution control, voltage, current, temperature and other signal acquisition, network communication, operation display, and control power supply. The 15.6-inch touch screen and intrinsically safe keyboard can be used for human-computer interaction, and the industrial switch can realize underground network communication, upload data to the ground centralized control center or communicate with other underground equipment.

[0033] The secondary wiring compartment is an independent explosion-proof compartment, with 20 A1 bell mouths and 4 A3 bell mouths reserved for the outside. The internal wiring connects the centralized control compartment with the external control lines and communication lines, and the lines are led out through the bell mouths to connect with other automation equipment. The secondary wiring compartment provides a safe and reliable explosion-proof channel for the lead-out of control lines and communication lines, meeting the needs of automation wiring, and wiring and maintenance are safe and convenient.

[0034] In addition, the trolley-type circuit breaker of the vacuum distribution device of the present invention adopts a sealed pole type, is maintenance-free, has a high segmentation capacity, and is equipped with an electric chassis. The circuit breaker is installed in the distribution circuit compartment, and its electric chassis cooperates with the mechanical structure of the distribution circuit compartment to realize the conversion of the circuit breaker between the working position and the maintenance test position. The circuit breaker and the front door locking handle of the distribution circuit compartment have a mechanical and electrical locking relationship to ensure safe operation. The grounding device is located on the output cable side of the distribution device and is electrically connected to the grounding knife switch of the busbar compartment. In the maintenance state, the output load cable can be grounded for cable discharge and grounding protection, and the position status of the grounding switch can be monitored by video.

[0035] The circuit breaker can be opened and closed electrically. The control command is issued through the circuit breaker trolley controller in the centralized control compartment to drive the electric operating mechanism inside the circuit breaker to realize the opening and closing action. It can also be opened and closed manually. The manual opening and closing buttons on the front door of the distribution circuit compartment are used to directly operate the mechanical mechanism of the circuit breaker for opening and closing. There is a reliable mechanical and electrical interlock between the chassis and the circuit breaker closing and opening states. When the circuit breaker is in the closed state, the mechanical interlocking mechanism prevents the chassis from moving, and the electrical interlocking signal is transmitted to the chassis control circuit, making it unable to be operated. Only when the circuit breaker is opened can the chassis be rocked in and out to the test position or working position.

[0036] The circuit breaker is equipped with an electric chassis trolley, which uses a motor or a manually driven screw to drive the circuit breaker to switch between the working position and the maintenance test position. When the operation of the electric trolley driving motor is blocked (improper installation or mechanism stuck) and reaches the protection condition, the motor is braked immediately and the motor is driven in reverse to release the stuck state.

[0037] The three-phase voltage transformer provides voltage signals for metering and protection. It is installed in the busbar compartment and connected to the integrated protection device in the centralized control compartment. The control transformer provides centralized power supply for the control circuit in the device. It is also installed in the busbar compartment and connected to various control and protection devices in the centralized control compartment to ensure safe and reliable control power supply.

[0038] The high-voltage live display is installed on the front door of the distribution circuit compartment. Once each distribution circuit is energized, the corresponding indicator light will light up to remind the operator to pay attention to safety and avoid electric shock accidents. At the same time, it has a signal connection with the 4.3-inch display screen in the distribution circuit compartment, and the live status information can be displayed on the display screen.

[0039] High-definition industrial-grade micro cameras are installed in the power distribution circuit compartment to monitor the positions of the moving contacts and grounding switches of each circuit breaker. Video signals can be uploaded to the ground control center through the underground network to achieve visualization of remote operation. The camera is connected to the industrial switch in the centralized control compartment and transmits video signals through the network. The control process is as follows: Figure 2 shown.

[0040] Wireless temperature sensors are installed at the main circuit terminals of each distribution circuit of the power distribution device. Each circuit has 6 temperature measurement channels, which monitor the temperature of key points online in real time and generate temperature curves. The temperature data can be displayed locally on the 4.3-inch display screen in the distribution circuit compartment, or remotely monitored, and the temperature data can be transmitted through the wireless communication module connected to the relevant equipment in the centralized control compartment.

[0041] The functions of the explosion-proof and intrinsically safe high-voltage combined vacuum power distribution device of the present invention include:

[0042] (1) Overcurrent protection

[0043] The high-voltage combined vacuum power distribution device performs overcurrent inverse time protection for current changes during the working process. When intermittent overload occurs, the overload energy is released and accumulated based on the ratio of the overload current to the rated working current and the duration of the overload, and inverse time protection is performed. In the high-voltage combined vacuum power distribution device, since the resistance of the device can be regarded as a constant under normal operating conditions, only the relationship between current and time is considered. Specifically, the following two methods can be used:

[0044] 1) Rated current is I e, the overload current is I0, first calculate the overload multiple k = I0 / I e Then calculate the overload energy accumulation value E a : Where n is the number of sampling times, k i is the overload multiple of the i-th sampling, and Δt is the sampling interval. When the overload disappears, calculate the energy release. First, set the energy release coefficient α, and the energy release calculation method is: Where E r is the energy after release, t r It is the duration after the overload disappears. α can be determined through experiments in engineering practice.

[0045] During intermittent overload, the above method is used to calculate the accumulated and released energy. When the sum E accumulates to the preset threshold, the inverse time protection action is triggered. The protection action time E is the sum of the accumulated and released energies exceeding a preset threshold, and the accumulated and released energies are preset constants.

[0046] 2) Set the digital integral filter. The input of the filter is the overload multiple and time interval. The output of the filter is the overload energy accumulation value E. a .

[0047] E a (n) = E a (n-1)+k 2 (n)Δt

[0048] Where n is the sampling time, E a (n) is the accumulated overload energy value at the moment, E a (n-1) is the accumulated overload energy value at the previous moment, and k(n) is the overload multiple at the nth moment.

[0049] When the overload disappears, calculate the released energy, E a (n) = E a (n-1)×e -βΔt , where β is the preset attenuation coefficient. It can also be determined through experiments in engineering practice. a When the set threshold is exceeded, the inverse time protection action is triggered, and the action time is also determined in an inverse relationship. C is a constant. This method effectively filters out the influence of short-term interference and noise on overload energy calculation and improves the accuracy of protection.

[0050] (2) Short circuit protection

[0051] The operating current of the short-circuit protection can be set arbitrarily within 1.5-10 times of the rated current value, and the setting value error shall not exceed ±10%. The short-circuit protection operating time shall be less than 0.1s.

[0052] (3) Insulation monitoring protection, the operating characteristics are shown in Table 1.

[0053] Table 1 Insulation monitoring protection action characteristics

[0054] Protect working status Reliable action Allow Actions Action not allowed Loop resistance between monitoring line and ground wire >1.5K 0.8～1.5K <0.8K Insulation resistance between monitoring line and ground wire ＜3.0K 3.0～5.5K ＞5.5K

[0055] (4) Grounding (leakage) protection, including:

[0056] ① Zero-sequence power directional grounding (leakage) protection, its characteristics are shown in Table 2.

[0057] Table 2 Zero-sequence power directional grounding (leakage) protection characteristics

[0058]

[0059] ②Zero-sequence current type grounding (leakage) protection

[0060] The zero-sequence current type grounding (leakage) protection has a primary zero-sequence current of 0.5, 1.0, 2.0, 4.0, and 6.0 A. The action time is 0.1s, and the error value is less than ±10%.

[0061] (5) Voltage protection, including:

[0062] Low voltage protection: Reliable protection when the grid voltage drops below 75% of the rated value, and the low voltage protection action time is ≤ 5 seconds.

[0063] Overvoltage protection: Reliable protection when the grid voltage rises to more than 115% of the rated value, and the overvoltage protection action time is ≤5 seconds.

[0064] The action values ​​of low voltage and overvoltage protection can also be preset as specified.

[0065] (6) Phase balance: When any phase power supply is disconnected and the load current is 50% lower or higher than the other two phases, the protection will be activated after a delay of 5 to 30 seconds. The phase balance function has an on and off menu, and the user can freely choose to turn it on or off.

[0066] (7) Wind power interlock: Used in conjunction with the gas power cut-off device. After the gas power cut-off device is activated, it will output and display that the gas is out of limit.

[0067] (8) The system has a password function to prevent unauthorized operation. The password function can be turned on or off.

[0068] (9) Fault recording function:

[0069] The international standard recording file format is used to store the fault recording data of 37 cycles before the fault and 20 cycles after the fault, which can be queried at any time to facilitate the analysis of the cause of the fault. A variety of fault recording start modes are convenient for finding and analyzing the cause of the fault after the accident, and can also guide users to set the fixed value. The switch closing recording function is added to analyze the changes in voltage and current signals at the moment of switch closing.

[0070] (10) Anti-over-tripping function: multiple high-voltage power installation devices are networked through optical fiber lines to achieve anti-over-tripping function underground and above ground; system fault information is shared, with fault selectivity and speed; it is not affected by the operating mode; it is easy to install and debug, and only needs to connect the optical fiber according to the diagram; the system is easy to expand and will not have any impact on the original system; the protection device and optical fiber hub have optical fiber fault self-detection function, and can transmit the optical fiber fault signal to the system platform.

[0071] Each high-voltage distribution device switch transmits faults through optical fiber. There will be a hierarchical delay time between each level. The default hierarchical delay on the comprehensive protection menu is 60ms. The action time of the upper level will be 60ms longer than the action time of the lower level. If leakage or short circuit faults occur between the upper and lower levels at the same time, the lower-level distribution device switch will actively transmit the fault information to the previous-level distribution device switch through optical fiber. The upper-level distribution device switch will add the hierarchical delay time to the original fault delay time, and the fault command will not be issued, and the distribution device switch will not be opened. It can be achieved that the lower-level distribution device switch is opened due to leakage or short circuit faults, and the upper-level distribution device switch is not opened.

[0072] When the whole system is working and the power supply is normal, the high voltage electricity is distributed to the main circuit terminals of each distribution circuit compartment through the busbar in the busbar compartment, the trolley-type circuit breaker is in the working position and closed, and the power is transmitted to the load. The three-phase voltage transformer collects the voltage signal, and the wireless temperature sensor monitors the temperature signal. These signals are transmitted to the integrated protection device and other equipment in the centralized control compartment for monitoring and analysis. If a fault occurs, such as overcurrent, overvoltage or abnormal temperature, the integrated protection device will issue a trip command according to the set protection setting, so that the circuit breaker is opened and the power supply of the fault circuit is cut off. At the same time, the fault information is recorded and can be uploaded to the ground centralized control center through the industrial switch.

[0073] The above applications are only some implementation methods of the present application. For those skilled in the art, several modifications and improvements can be made without departing from the creative concept of the present application, and these all belong to the protection scope of the present application.

Claims

1. A mine-use explosion-proof and intrinsically safe high-voltage combined vacuum power distribution device, characterized in that: It includes power distribution circuit compartment, busbar compartment, centralized control compartment and secondary independent wiring compartment; The power distribution circuit compartment is an independent flameproof compartment, and the busbar compartment adopts a two-layer reserved door structure, corresponding to the power distribution circuit compartment. The centralized control compartment is connected to the circuit breaker of the power distribution circuit compartment and the mutual inductor of the busbar compartment through control cables, receiving various sensor signals and issuing control instructions; The centralized control compartment is used to complete power distribution control, voltage, current, temperature signal acquisition, network communication, operation display, and control power supply.

2. A mine flameproof and intrinsically safe high-voltage combined vacuum power distribution device according to claim 1, characterized in that: The distribution circuit compartment is equipped with a trolley-type circuit breaker and a camera.

3. A mine flameproof and intrinsically safe high-voltage combined vacuum power distribution device according to claim 2, characterized in that: The busbar compartment is equipped with busbars, main circuit terminals, grounding switches, load cables, varistors, current transformers, three-phase five-column transformers, and PT transformers.

4. A mine flameproof and intrinsically safe high-voltage combined vacuum power distribution device according to claim 3, characterized in that: The centralized control compartment is equipped with integrated protection devices for each unit, PLC, circuit breaker trolley controller, industrial switch, 15.6-inch touch screen, miniature circuit breaker, relay, switching power supply, intrinsically safe power supply, and intrinsically safe keyboard.

5. A mine flameproof and intrinsically safe high-voltage combined vacuum power distribution device according to claim 4, characterized in that: The secondary wiring compartment reserves 20 A1 bell mouths and 4 A3 bell mouths for the outside. Its internal wiring connects the centralized control compartment with the external control lines and communication lines, and the lines are led out through the bell mouths to connect with other automation equipment.

6. A mine flameproof and intrinsically safe high-voltage combined vacuum power distribution device according to claim 5, characterized in that: When the vacuum power distribution device is supplying power, high voltage electricity is distributed to the main circuit terminals of each distribution circuit compartment through the busbar in the busbar compartment, the trolley-type circuit breaker is in the working position and closed, and the electric energy is transmitted to the load; the current transformer collects the current signal in the main circuit, the three-phase voltage transformer collects the voltage signal, and the wireless temperature sensor monitors the temperature signal, and transmits it to the comprehensive protection device in the centralized control compartment for monitoring and analysis.

7. A power distribution method using the explosion-proof and intrinsically safe high-voltage combined vacuum power distribution device for mining use according to claim 6, characterized in that: The vacuum power distribution device is used to perform overcurrent protection, short-circuit protection, insulation monitoring, grounding (leakage) protection, voltage protection, phase balance, wind power interlocking, fault recording and anti-over-tripping according to current and voltage signals.

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