CN117833721A - Full-variable-frequency-driven coal mining machine electrical system and frequency converter control method - Google Patents
Full-variable-frequency-driven coal mining machine electrical system and frequency converter control method Download PDFInfo
- Publication number
- CN117833721A CN117833721A CN202410017719.XA CN202410017719A CN117833721A CN 117833721 A CN117833721 A CN 117833721A CN 202410017719 A CN202410017719 A CN 202410017719A CN 117833721 A CN117833721 A CN 117833721A
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- Prior art keywords
- motor
- frequency converter
- contactor
- traction
- converter
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- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- 239000003245 coal Substances 0.000 title claims abstract description 31
- 238000005065 mining Methods 0.000 title claims abstract description 16
- 238000000034 method Methods 0.000 title claims description 9
- 238000006243 chemical reaction Methods 0.000 claims abstract description 5
- 238000002955 isolation Methods 0.000 claims 3
- 238000012544 monitoring process Methods 0.000 claims 1
- 238000005299 abrasion Methods 0.000 abstract description 4
- 238000010586 diagram Methods 0.000 description 7
- 230000004048 modification Effects 0.000 description 4
- 238000012986 modification Methods 0.000 description 4
- 230000001133 acceleration Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000004134 energy conservation Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Classifications
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21C—MINING OR QUARRYING
- E21C31/00—Driving means incorporated in machines for slitting or completely freeing the mineral from the seam
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21C—MINING OR QUARRYING
- E21C31/00—Driving means incorporated in machines for slitting or completely freeing the mineral from the seam
- E21C31/02—Driving means incorporated in machines for slitting or completely freeing the mineral from the seam for cutting or breaking-down devices
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P1/00—Arrangements for starting electric motors or dynamo-electric converters
- H02P1/02—Details of starting control
- H02P1/022—Security devices, e.g. correct phase sequencing
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P1/00—Arrangements for starting electric motors or dynamo-electric converters
- H02P1/16—Arrangements for starting electric motors or dynamo-electric converters for starting dynamo-electric motors or dynamo-electric converters
- H02P1/54—Arrangements for starting electric motors or dynamo-electric converters for starting dynamo-electric motors or dynamo-electric converters for starting two or more dynamo-electric motors
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P29/00—Arrangements for regulating or controlling electric motors, appropriate for both AC and DC motors
- H02P29/02—Providing protection against overload without automatic interruption of supply
- H02P29/032—Preventing damage to the motor, e.g. setting individual current limits for different drive conditions
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P5/00—Arrangements specially adapted for regulating or controlling the speed or torque of two or more electric motors
- H02P5/46—Arrangements specially adapted for regulating or controlling the speed or torque of two or more electric motors for speed regulation of two or more dynamo-electric motors in relation to one another
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Mining & Mineral Resources (AREA)
- Mechanical Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Geology (AREA)
- Computer Security & Cryptography (AREA)
- Control Of Multiple Motors (AREA)
Abstract
The invention provides a full-frequency-conversion-driven coal mining machine electrical system, which comprises: the contactor comprises a left cutting contactor, a pump contactor, a traction contactor and a right cutting contactor, the frequency converter comprises a left cutting frequency converter, a pump frequency converter, a traction frequency converter and a right cutting frequency converter, the motor comprises a left cutting motor, a pump motor, a traction motor and a right cutting motor, the disconnecting switch is sequentially connected with the left cutting contactor, the left cutting frequency converter and the left cutting motor, the disconnecting switch is further sequentially connected with the pump contactor, the pump frequency converter and the pump motor, the disconnecting switch is further sequentially connected with the traction contactor, the traction frequency converter and the traction motor, and the disconnecting switch is further sequentially connected with the right cutting contactor, the right cutting frequency converter and the right cutting motor. The motor is driven based on full frequency conversion, so that soft start of the cutting motor, the traction motor and the pump motor can be realized; meanwhile, the motor can smoothly run when starting and stopping through the arrangement of the frequency converter, and the generated vibration and abrasion are reduced.
Description
Technical Field
The invention relates to the technical field of engineering machinery electricity, in particular to a full-variable-frequency driving technology for a coal mining machine.
Background
Existing shearer generally use motor drive. The coal cutter comprises a cutting motor, a traction motor and a pump motor, wherein the cutting motor usually operates at power frequency, and the rotating speed of the motor is a fixed value, so that the rotating speed of a roller driven by the cutting motor is fixed; the traction motor is driven by the frequency converter, so that the control of the traction speed and direction is realized; the pump motor also typically operates at power frequency, with the motor speed being a fixed value.
The cutting efficiency of the coal cutter is reduced along with the increase of the drum rotation speed, the lump coal rate in the coal mining process is reduced along with the increase of the drum rotation speed, and the coal charging rate in the coal mining process is improved along with the increase of the drum rotation speed. However, the drum rotation speed of the coal cutter is fixed, the drum rotation speed cannot be adjusted according to the condition change of the coal mining working condition, and the requirements on cutting efficiency, quick coal rate and coal loading rate cannot be met under the condition change. In addition, the cutting motor of the coal cutter is directly driven by a power supply, the starting current can reach 7 times of the rated current of the motor, the power stress of a motor winding can be increased, and the heating of the motor is increased; meanwhile, voltage fluctuation of a power supply network is caused by the surge of starting current, so that operation of other equipment is influenced; meanwhile, when the motor is started and stopped at the power frequency, the motor, the mechanical shaft and the gear generate intense vibration, the vibration can aggravate the abrasion and loss of mechanical parts, and the service lives of the motor and mechanical equipment are shortened. Thirdly, the cutting motor and the pump motor generally operate at power frequency, the rotating speed of the motor cannot be dynamically adjusted according to the load condition, unnecessary energy waste can be caused during operation, and the energy consumption is high. In addition, the cutting motor and the pump motor are directly driven by a power supply, and can only detect parameters such as motor current, motor temperature, electric leakage and the like to realize a simple protection function, so that rapid overcurrent protection cannot be realized, and protection such as power supply overvoltage, power supply undervoltage, motor phase loss, motor locked rotor and the like cannot be realized.
Disclosure of Invention
In view of the above-mentioned drawbacks of the prior art, an object of the present invention is to provide a fully variable frequency drive electric system for a coal mining machine, which can adjust the speed of a motor, reduce the current and the applied stress when the motor is started, reduce the heat of the motor, and realize the protection of the current and the voltage.
The invention provides a full-variable-frequency-driven coal mining machine electric system which comprises an isolating switch, wherein the isolating switch is sequentially connected with a contactor, a frequency converter and a motor, the contactor comprises a left cutting contactor, a pump contactor, a traction contactor and a right cutting contactor, the frequency converter comprises a left cutting frequency converter, a pump frequency converter, a traction frequency converter and a right cutting frequency converter, the motor comprises a left cutting motor, a pump motor, a traction motor and a right cutting motor, the isolating switch is sequentially connected with the left cutting contactor, the left cutting frequency converter and the left cutting motor, the isolating switch is sequentially connected with the pump contactor, the pump frequency converter and the pump motor, the isolating switch is sequentially connected with the traction contactor, the traction frequency converter and the traction motor, and the isolating switch is sequentially connected with the right cutting contactor, the right cutting frequency converter and the right cutting motor.
Further, when any one of the left cutting contactor, the pump contactor and the right cutting contactor fails, the isolating switch is directly and sequentially connected with the left cutting frequency converter and the left cutting motor, or the isolating switch is directly and sequentially connected with the pump frequency converter and the pump motor, or the isolating switch is directly and sequentially connected with the right cutting frequency converter and the right cutting motor.
Further, the traction frequency converter comprises a left traction frequency converter and a right traction frequency converter, the traction motor comprises a left traction motor and a right traction motor, the left traction frequency converter is connected with the left traction motor, and the right traction frequency converter is connected with the right traction motor.
Further, the contactor is the same as the contactor, and the frequency converter connected with the contactor is the same frequency converter
Further, when the frequency converter is connected with the contactor, the three-phase power supply is input to the frequency converter from the contactor, and then the motor is controlled to work through the frequency converter.
Further, the input end of the three-phase power supply is connected to a control system of the frequency converter.
Further, the output current of the control system is fed back to the control system.
The invention also provides a control method of the frequency converter, the frequency converter comprises a control system, and after the three-phase power supply is input to the frequency converter from the contactor, the control system monitors the values of the input current and the output current of the frequency converter and the value of the input voltage of the frequency converter.
Further, the overload protection circuit also comprises a step of comparing the output current with the rated current of the motor, and limiting the value of the output current to be the rated current of the motor if the value of the output current is larger than the value of the rated current of the motor, so that overload and overcurrent protection of the motor is realized.
Further, the control system monitors three phases of the output current, such as whether the three phases are balanced or not, whether the motor is in shortage or not, and the like.
Further, the control system also comprises a step of setting the maximum limit and the minimum limit of the input voltage, a step of comparing the input voltage with the maximum limit and the minimum limit, and a step of setting the input voltage as the maximum limit or the minimum limit if the value of the input voltage P1 is larger than the maximum limit or smaller than the minimum limit so as to realize the protection of the overvoltage and the undervoltage of the power supply.
In summary, in the invention, the traction transformer is removed on the basis of the original main loop of the coal mining machine, and the isolating switch is reserved, and each motor is connected with a frequency converter and a contactor, so that the speed of the motor is adjusted, the invention is suitable for the dynamic adjustment of cutting efficiency, lump coal rate and coal loading rate under the condition of changing working surfaces and working conditions of different coal qualities, improves the cutting efficiency, and meets the requirements of green energy conservation. All motors are driven by the frequency converter, so that soft start of the motors can be realized, the current for starting the motors is reduced, the electric stress and the electric loss of the motors are reduced, and the impact on a power grid is reduced; meanwhile, the setting of the acceleration time and the deceleration time of the running working condition of the coal mining machine is realized through the setting of the frequency converter, so that the motor can run smoothly when starting and stopping, and the generated vibration and abrasion are reduced. In addition, according to the control system in the frequency converter, the protection functions of overcurrent, overload, overvoltage, undervoltage, phase loss of the motor, locked rotor of the motor and the like can be realized.
Drawings
Fig. 1 shows a schematic structural diagram of the electrical system of the coal mining machine of the present invention.
Fig. 2 shows a schematic diagram of the operation of the frequency converter.
Fig. 3 shows a second schematic structural diagram of the electrical system of the shearer of the present invention.
Description of element reference numerals
100-coal cutter electrical system
01-isolating switch
02-contactor
021-left cutting contactor
022-pump contactor
023-traction contactor
024-right cutting contactor
03-frequency converter
031-left cutting frequency converter
032-pump frequency converter
033-traction frequency converter
0331-left traction frequency converter
0332-right traction frequency converter
034-right cutting frequency converter
04-motor
041-left cutting motor
042-pump motor
043-traction motor
0431-left traction motor
0432-right traction motor
044-right cutting motor
C-control system
I1-input Current
I2-output current
P-three phase power supply
V-input voltage
Detailed Description
Further advantages and effects of the present invention will become apparent to those skilled in the art from the disclosure of the present invention, which is described by the following specific examples.
Please refer to fig. 1-2. It should be understood that the structures, proportions, sizes, etc. shown in the drawings are for illustration purposes only and should not be construed as limiting the invention to the extent that it can be practiced, since modifications, changes in the proportions, or otherwise, used in the practice of the invention, are not intended to be critical to the essential characteristics of the invention, but are intended to fall within the spirit and scope of the invention. Also, the terms such as "upper," "lower," "left," "right," "middle," and "a" and the like recited in the present specification are merely for descriptive purposes and are not intended to limit the scope of the invention, but are intended to provide relative positional changes or modifications without materially altering the technical context in which the invention may be practiced.
Fig. 1 shows a schematic structural diagram of the electrical system of the coal mining machine of the present invention. Fig. 2 shows a schematic diagram of the operation of the frequency converter. Fig. 3 shows a second schematic structural diagram of the electrical system of the shearer of the present invention.
As shown in fig. 1, the coal mining machine electrical system 100 includes: the isolating switch 01 is respectively connected with 4 contactors 02, the left cutting contactor 021, the pump contactor 022, the traction contactor 023 and the right cutting contactor 024 are sequentially arranged from left to right, any contactor 02 is respectively connected with a frequency converter 03, the left cutting frequency converter 031, the pump frequency converter 032, the traction frequency converter 033 and the right cutting frequency converter 034 are sequentially arranged from left to right, any frequency converter 03 is respectively connected with a motor 04, and the left cutting motor 041, the pump motor 042, the traction motor 043 and the right cutting motor 044 are sequentially arranged from left to right. Wherein, traction inverter 033 includes left traction inverter 0331 and right traction inverter 0332, traction motor 043 includes left traction motor 0431 and right traction motor 0432, left traction inverter 0331 connects left traction motor 0431, right traction inverter 0332 connects right traction motor 0432. Thus, 4 control paths were formed, in order: the path from the disconnecting switch 01 to the left cutting motor 041 sequentially passes through the left cutting contactor 021 and the left cutting frequency converter 031, the path from the disconnecting switch 01 to the pump motor 042 sequentially passes through the pump contactor 022 and the pump frequency converter 032, the path from the disconnecting switch 01 to the traction contactor 023 is divided into 2 paths from the left traction frequency converter 0331 to the left traction motor 0431 and from the right traction frequency converter 0332 to the right traction motor 0432, and the path from the disconnecting switch 01 to the right cutting motor 044 sequentially passes through the right cutting contactor 024 and the right cutting frequency converter 034.
In a preferred embodiment, the left cut inverter 031, the pump inverter 032, the left traction inverter 0331, the right traction inverter 0332 and the right cut inverter 034 are all the same kind of inverter 03, and the left cut contactor 021, the pump contactor 022, the traction contactor 023 and the right cut contactor 023 are all the same kind of contactor 02. When any contactor 02 is connected with the corresponding frequency converter 03 and the corresponding motor 04 in turn, a connection schematic diagram as shown in fig. 2 is adopted.
As shown in fig. 2, the three-phase power P is input from any contactor 02 to the corresponding inverter 03, and the inverter 03 drives the corresponding motor 04 to operate. The control system C in the frequency converter 03 detects the input current I1 and the output current I2, compares the value of the output current I2 with the value of the rated current of the motor, and limits the value of the output current I2 to the value of the rated current of the motor if the value of the output current I2 is larger than the value of the rated current of the motor, so that overload and overcurrent protection of the motor is realized; the control system C can also monitor whether the three phases of the value of the output current I2 are balanced or not and whether the motor is in open phase or not; meanwhile, the control system C detects the input voltage V of the three-phase power supply P, compares the maximum limit value and the minimum limit value of the input voltage V, and if the value of the input voltage V is larger than the maximum limit value or smaller than the minimum limit value, sets the input voltage V as the maximum limit value or the minimum limit value, so as to realize the protection of the overvoltage and the undervoltage of the power supply.
In another embodiment, as shown in fig. 3, when any one or more of the left cut contactor 021, the pump contactor 022, and the right cut contactor 024 fails, the disconnector 01 is directly connected in sequence to the left cut inverter 031 and the left cut motor 041, or the disconnector 01 is directly connected in sequence to the pump inverter 032 and the pump motor 042, or the disconnector 01 is directly connected in sequence to the right cut inverter 034 and the right cut motor 044.
In summary, in the invention, the isolating switch 01 is sequentially connected with the contactor 02 and the frequency converter 03 and then reaches the motor 04, and the frequency converter drives the motor to work, so that the speed of the motor can be adjusted, the cutting efficiency, the lump coal rate and the coal loading rate can be dynamically adjusted under the condition of changing working surfaces and working conditions of different coal qualities, the cutting efficiency is improved, and the environment-friendly energy conservation is satisfied.
The motor is driven based on full frequency conversion, so that soft start of the cutting motor, the traction motor and the pump motor can be realized, the current for starting the motor is reduced, the electric stress and the electric loss of the motor are reduced, and the impact on a power grid is reduced; meanwhile, the setting of the acceleration time and the deceleration time of the running working condition of the coal mining machine is realized through the setting of the frequency converter, so that the motor can run smoothly when starting and stopping, and the generated vibration and abrasion are reduced.
In addition, according to the control system in the frequency converter, the protection functions of overcurrent, overload, overvoltage, undervoltage, phase loss of the motor, locked rotor of the motor and the like can be realized.
The above embodiments are merely illustrative of the principles of the present invention and its effectiveness, and are not intended to limit the invention. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is intended that all equivalent modifications and variations of the invention be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.
Claims (11)
1. The utility model provides a coal-winning machine electrical system of full frequency conversion drive, its characterized in that, includes isolator, isolator connects gradually contactor, converter and motor, wherein, the contactor includes left cut contactor, pump contactor, traction contactor and right cut contactor, the converter includes left cut converter, pump converter, traction converter and right cut converter, the motor includes left cut motor, pump motor, traction motor and right cut motor, isolator connects gradually left cut contactor left cut converter with left cut motor, isolator still connects gradually pump contactor pump converter with pump motor, isolator still connects gradually traction contactor traction converter with traction motor, isolator still connects gradually right cut contactor right cut converter with right cut motor.
2. The full-frequency drive shearer loader electrical system of claim 1, wherein the isolation switch is connected in sequence to the left cutting frequency converter and the left cutting motor, the isolation switch is further connected in sequence to the pump frequency converter and the pump motor, and the isolation switch is further connected in sequence to the right cutting frequency converter and the right cutting motor.
3. The fully variable frequency drive shearer loader electrical system of claim 1, wherein the traction frequency converter comprises a left traction frequency converter and a right traction frequency converter, the traction motor comprises a left traction motor and a right traction motor, the left traction frequency converter is connected with the left traction motor, and the right traction frequency converter is connected with the right traction motor.
4. A fully variable frequency drive shearer loader electrical system as claimed in claim 1 wherein the contactor is the same and the frequency converter connected to the contactor is the same frequency converter.
5. The fully variable frequency drive shearer loader electrical system of claim 1, wherein when the frequency converter is connected with the contactor, three-phase power is input to the frequency converter from the contactor, and then the motor is controlled to work through the frequency converter.
6. A fully variable frequency drive shearer loader electrical system as in claim 5, wherein the input of the three phase power source is wired to the control system of the frequency converter.
7. The fully variable frequency drive shearer loader electrical system of claim 6, wherein the output current of the control system is fed back to the control system.
8. A method for controlling a frequency converter applied to the full-frequency-conversion-driven electric system of the coal mining machine according to any one of claims 1 to 7, wherein the frequency converter comprises a control system, and the control system monitors the values of the input current and the output current of the frequency converter and the value of the input voltage of the frequency converter after a three-phase power supply is input to the frequency converter from a contactor.
9. The method of claim 8, further comprising the step of comparing the output current to a rated current of the motor.
10. The method of claim 8, further comprising the control system monitoring three phases of the output current.
11. The method of claim 8, further comprising setting maximum and minimum limits for the input voltage in the control system and comparing the input voltage to the maximum and minimum limits.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410017719.XA CN117833721A (en) | 2024-01-05 | 2024-01-05 | Full-variable-frequency-driven coal mining machine electrical system and frequency converter control method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410017719.XA CN117833721A (en) | 2024-01-05 | 2024-01-05 | Full-variable-frequency-driven coal mining machine electrical system and frequency converter control method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117833721A true CN117833721A (en) | 2024-04-05 |
Family
ID=90523953
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202410017719.XA Pending CN117833721A (en) | 2024-01-05 | 2024-01-05 | Full-variable-frequency-driven coal mining machine electrical system and frequency converter control method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117833721A (en) |
-
2024
- 2024-01-05 CN CN202410017719.XA patent/CN117833721A/en active Pending
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