CN117595745A - Variable-frequency bucket opening control system and method - Google Patents
Variable-frequency bucket opening control system and method Download PDFInfo
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- CN117595745A CN117595745A CN202311311384.4A CN202311311384A CN117595745A CN 117595745 A CN117595745 A CN 117595745A CN 202311311384 A CN202311311384 A CN 202311311384A CN 117595745 A CN117595745 A CN 117595745A
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- 238000005065 mining Methods 0.000 abstract description 2
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- 238000004804 winding Methods 0.000 description 9
- 230000007246 mechanism Effects 0.000 description 8
- 229910000831 Steel Inorganic materials 0.000 description 5
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- 238000010586 diagram Methods 0.000 description 3
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- 238000007664 blowing Methods 0.000 description 1
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- 238000003825 pressing Methods 0.000 description 1
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/10—Greenhouse gas [GHG] capture, material saving, heat recovery or other energy efficient measures, e.g. motor control, characterised by manufacturing processes, e.g. for rolling metal or metal working
Abstract
The invention discloses a variable-frequency bucket opening control system and a variable-frequency bucket opening control method, and belongs to the technical field of mining equipment. The power supply control unit is used for responding to the power supply running state, triggering a guy rope signal and outputting the guy rope signal; the main command control unit responds to the opening operation instruction, triggers and outputs an opening signal, and the output time of the opening signal is later than that of the guy rope signal; the frequency converter receives the guy rope signal, responds to the guy rope signal, starts and outputs a preset first torque to the bucket opening motor until receiving the bucket opening signal; the frequency converter receives the opening signal, responds to the opening signal to increase the first torque to the second torque in a preset time period and outputs the second torque to the opening motor so as to control the torque of the opening motor and open the hopper bolt. The impact of moment mutation on machinery can be avoided, the working efficiency is improved, and the problem that components in a direct current control system are prone to failure to influence the bucket opening efficiency is solved.
Description
Technical Field
The invention relates to the technical field of mining equipment, in particular to a variable-frequency bucket opening control system and a variable-frequency bucket opening control method.
Background
The statements in this section merely relate to the background of the present disclosure and may not necessarily constitute prior art.
The WK-10B electric shovel is a third generation improved model of the WK-10 electric shovel, the existing bucket opening mechanism is a direct current control system, and main components (from control to execution mechanism) of the existing bucket opening mechanism comprise a main command controller, an intermediate relay, a direct current contactor, a resistor group, a direct current motor and the like.
The motor is mainly series excited and shunt excited, and has the characteristic of series excited motor without the danger of no-load flying speed, and when the load torque suddenly increases, the electromagnetic torque is promoted to increase faster due to the increase of current in the series winding and the increase of magnetic flux, so as to overcome the suddenly increased load torque. When the motor is powered on for a long time, RK1 is a shunt winding, RK2 is a series winding, RK3 is a complementary pole, when the motor is not in a bucket opening state, a large resistor R28 is connected in series with an armature loop, so that the torque generated by the motor can only tension a bucket opening rope, the motor is not overheated due to small armature current, and when the motor is in a bucket opening state, a direct current contactor KM15 is short-circuited with the series resistor, so that the bucket opening motor instantaneously emits large pulling force, and a bucket door is opened.
However, when the series connection is reversed during debugging, the motor becomes a differential-excitation motor, so that the motor feels weak, and even cannot be used for opening a bucket, and the mode is widely applied to WK-10B excavators. In the direct current control system, the KM15 direct current contactor is often not provided with a secondary bucket or is normally opened (the bucket door is not closed) due to the burning of the main contact. In the main loop, the WK-10B electric shovel is not opened once, is not opened twice or is opened once/twice or is opened twice or is not opened twice frequently due to the damage or the blowing of the R27/R28/R29 resistor group. The resistor bank may have a large amount of heat dissipated during normal operation, and sometimes the resistor may be hot red. The ceramic frame in the center of the resistor can also cause other electrical appliance faults due to long-time baking, so that troubleshooting fault points are increased when faults occur, the overhaul efficiency is low, and the daily production overhaul arrangement is seriously influenced.
The difficulty of applying the variable-frequency speed-regulating bucket opening device on the WK-10B electric shovel is larger than that of the variable-frequency shovel, firstly, the WK-10B electric shovel is not provided with a PLC controller, and a given signal of the frequency converter cannot be controlled in real time through the PLC controller; secondly, the main controller of the WK-10B electric shovel does not push and recover signals, and the frequency converter cannot adjust given signals according to the direction of the pushing mechanism.
Disclosure of Invention
In order to solve the defects in the prior art, the invention provides a variable-frequency bucket opening control system and a variable-frequency bucket opening control method, which are combined with the existing direct-current control system of an electric shovel, and the variable-frequency bucket opening control system of the electric shovel is modified by adopting a variable-frequency technology, so that variable-frequency bucket opening control can be realized without a plc controller.
In a first aspect, the present invention provides a variable frequency hopper opening control system;
a variable frequency hopper opening control system comprising:
the power supply control unit is used for responding to the power supply running state, triggering a guy rope signal and outputting the guy rope signal;
the main command control unit is used for responding to a bucket opening operation instruction, triggering a bucket opening signal and outputting the bucket opening signal, wherein the output time of the bucket opening signal is later than that of the guy rope signal;
the frequency converter is electrically connected with a bucket opening motor and is used for receiving a guy rope signal, starting the frequency converter in response to the guy rope signal and outputting a preset first torque to the bucket opening motor until the bucket opening signal is received;
the frequency converter receives a bucket opening signal, responds to the bucket opening signal, increases the first torque to the second torque in a preset time period, and outputs the second torque to the bucket opening motor; so as to control the moment of the bucket opening motor and open the bucket bolt.
Further, the power supply control unit comprises a three-phase rectifier bridge power supply and a contactor, wherein the three-phase rectifier bridge power supply is electrically connected with a coil of the contactor, and an auxiliary contact of the contactor is electrically connected with the first end of the frequency converter.
Preferably, the auxiliary contact of the contactor is a normally open contact.
Further, the master control unit comprises a master switch, a first relay and a second relay, the master switch is electrically connected with the coil of the first relay, the auxiliary contact of the first relay is electrically connected with the coil of the second relay, and the auxiliary contact of the second relay is electrically connected with the second end of the frequency converter.
Preferably, the auxiliary contacts of the first relay and the second relay are normally open contacts.
Further, an encoder is arranged in the bucket opening motor and is used for collecting the speed and the direction of the bucket opening motor and transmitting the speed and the direction to the frequency converter.
Further, the frequency converter further comprises a brake resistor, wherein the first end of the brake resistor is electrically connected with the third end of the frequency converter, and the fourth end of the frequency converter is electrically connected with the second end of the brake resistor.
In a second aspect, the invention provides a variable frequency bucket opening control method;
a variable frequency hopper opening control method, comprising:
acquiring a guy rope signal, responding to the guy rope signal, starting a frequency converter and outputting a preset first torque to the bucket opening motor until receiving the bucket opening signal;
responding to the first torque increased to the second torque by the bucket opening signal in a preset time period and outputting the second torque to the bucket opening motor so as to control the torque of the bucket opening motor and open a bucket bolt;
the guy rope signal is output by the power supply control unit in response to the power supply running state, and the bucket opening signal is triggered by the main control unit in response to the bucket opening running instruction.
Further, the frequency converter controls the bucket opening motor to output a first moment and a second moment according to the first moment, the second moment is larger than the first moment, and the first moment is larger than a moment threshold value.
Further, the preset time period is 1 s-2 s, the first torque is 4-6% of the torque, and the second torque is 55-65% of the torque.
Compared with the prior art, the invention has the beneficial effects that:
1. the technical scheme provided by the invention is improved on the basis of the WK-10B electric shovel direct current control system, and components which are easy to fail in the existing direct current control system are abandoned, so that the normal control of the bucket opening is prevented from being influenced by the failure.
2. According to the technical scheme provided by the invention, the control of the frequency converter signal is realized by only utilizing the frequency converter and the contactor and the relay in the existing direct current control system; the frequency converter outputs 5% torque in the guy rope stage by adopting a 2-gear torque slope setting mode, and the frequency converter increases the output torque to 60% in a slope within 1.5s when the bucket is opened, so that the bucket bolt is smoothly opened, and the impact of moment abrupt change on machinery is avoided.
3. According to the technical scheme provided by the invention, the braking resistor consumes the energy fed back to the DC bus of the frequency converter when the motor is in a power generation state, so that the overhigh voltage of the DC bus is avoided.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention.
FIG. 1 is a schematic diagram of a system architecture according to an embodiment of the present invention;
FIG. 2 is a schematic circuit diagram of an embodiment of the present invention;
fig. 3 is a schematic diagram of a 2-speed torque ramp setting mode according to an embodiment of the present invention.
Detailed Description
It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the invention. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular forms also are intended to include the plural forms, and furthermore, it is to be understood that the terms "comprises" and "comprising" and any variations thereof are intended to cover non-exclusive inclusions, such as, for example, processes, methods, systems, products or devices that comprise a series of steps or units, are not necessarily limited to those steps or units that are expressly listed, but may include other steps or units that are not expressly listed or inherent to such processes, methods, products or devices.
Embodiments of the invention and features of the embodiments may be combined with each other without conflict.
Example 1
In the prior art, a direct current control system applied to the WK10B electric shovel has complex components and parts and faults in the application process, so that a bucket is opened to cause faults, and the daily maintenance operation is influenced; accordingly, the present invention provides a variable frequency hopper opening control system.
Next, a variable frequency hopper opening control system disclosed in this embodiment will be described in detail with reference to fig. 1 to 3. The variable-frequency bucket opening control system comprises a power supply control unit, a main command control unit and a frequency converter, wherein the power supply control unit is used for responding to the running state of a power supply, triggering a guy rope signal and outputting the guy rope signal; the main command control unit is used for responding to the opening operation command, triggering and outputting an opening signal, and the output time of the opening signal is later than that of the guy rope signal; the frequency converter is electrically connected with the bucket opening motor and is used for receiving the guy rope signal, responding to the guy rope signal, starting and outputting a preset first torque to the bucket opening motor until receiving the bucket opening signal; the frequency converter receives a bucket opening signal, responds to the bucket opening signal, increases the first torque to the second torque in a preset time period, and outputs the second torque to the bucket opening motor; so as to control the moment of the bucket opening motor and open the bucket bolt.
Further, the power supply control unit comprises a three-phase rectifier bridge power supply and a contactor KM9, the three-phase rectifier bridge power supply is electrically connected with a coil of the contactor KM9, a DC24V power supply is electrically connected with an auxiliary contact of the contactor KM9, the auxiliary contact of the contactor KM9 is electrically connected with a first end DI0 of the frequency converter, and the auxiliary contact of the first contactor is a normally open contact.
The main control unit comprises a main switch, a first relay K14 and a second relay K571, a DC24V power supply is electrically connected with the main switch, the main switch is electrically connected with a coil of the first relay K14, a DC220V power supply is electrically connected with an auxiliary contact of the first relay K14, an auxiliary contact of the first relay K14 is electrically connected with a coil of the second relay K571, the DC24V power supply is electrically connected with an auxiliary contact of the second relay K571, an auxiliary contact of the second relay K571 is electrically connected with a second end DI12 of the frequency converter, and the auxiliary contacts of the first relay K14 and the second relay K571 are normally open contacts.
An encoder is arranged in the bucket opening motor, and is used for collecting the speed and the direction of the bucket opening motor and transmitting the speed and the direction to the frequency converter, so that the output of the frequency converter approaches to a more accurate set value infinitely, and closed-loop control is realized. Further, the frequency converter further comprises a brake resistor, wherein the first end of the brake resistor is electrically connected with the third end of the frequency converter, and the fourth end of the frequency converter is electrically connected with the second end of the brake resistor.
The working mode of this embodiment is as follows:
a rope tightening process:
after the electric shovel is started, the three-phase rectifier bridge power supply is connected, a closed loop is formed by the three-phase rectifier bridge power supply and the coil of the contactor KM9, the coil of the contactor KM9 is powered on, the contactor KM9 is attracted, an auxiliary contact (normally open point) of the contactor KM9 is closed, a guy rope signal is sent to a frequency converter DI0, the frequency converter is started, and the frequency converter outputs a small torque to the bucket opening motor for guying the bucket opening rope tightly, and when the pushing mechanism works, the bucket opening rope is kept to be wound and unwound along with the bucket.
And (3) a bucket opening process:
when the main command is opened to the bucket opening position, namely the main command switch is closed, the coil of the first relay K14 is electrified, the first relay K14 is attracted, the auxiliary contact (normally open point) of the first relay K14 is closed, a closed loop is formed by the DC220V power supply, the coil of the first relay K14 and the coil of the second relay K571, the coil of the second relay K571 is electrified, the auxiliary contact (normally open point) of the second relay K571 is closed, a bucket opening signal is sent to the position of the frequency converter DI2, the frequency converter starts to increase output torque, the torque is slowly (about 1.5 s) increased to the bucket opening torque, and all bolts are pulled open to finish bucket opening.
Example two
The embodiment discloses a variable frequency bucket opening control method, which comprises the following steps:
s1, acquiring a guy rope signal, responding to the guy rope signal, starting a frequency converter and outputting a preset first torque to a bucket opening motor until receiving a bucket opening signal. The guy rope signal is output by the power supply control unit in response to the power supply running state.
Specifically, after the electric shovel is started, the three-phase rectifier bridge power supply is connected, a closed loop is formed by the three-phase rectifier bridge power supply and the coil of the contactor KM9, the coil of the contactor KM9 is electrified, the contactor KM9 is attracted, an auxiliary contact (normally open point) of the contactor KM9 is closed, and a guy rope signal is sent to the position of the frequency converter DI 0.
S2, responding to the opening signal, increasing the first torque to the second torque in a preset time period, and outputting the second torque to the opening motor so as to control the torque of the opening motor and open the hopper bolt; wherein the bucket opening signal is mainly used for enabling the control unit to respond to the bucket opening operation instruction to trigger.
Wherein the preset time period is 1.5s, the first torque is 45% of the torque, the second torque is 60% of the torque, and the torque refers to the maximum torque of the bucket motor.
Specifically, when the main command is opened to the bucket opening position, namely the main command switch is closed, the coil of the first relay K14 is electrified, the first relay K14 is attracted, the auxiliary contact (normally open point) of the first relay K14 is closed, then the DC220V power supply, the coil of the first relay K14 and the coil of the second relay K571 form a closed loop, the coil of the second relay K571 is electrified, the auxiliary contact (normally open point) of the second relay K571 is closed, and the bucket opening signal is sent to the position of the frequency converter DI 2.
Further, the frequency converter controls the bucket opening motor to output a first moment N2 and a second moment N3 according to the first moment and the second moment, the second moment is larger than the first moment, and the first moment is larger than a moment threshold value N1.
Specifically, when the electric shovel works, the winding drum winding and unwinding actions are determined by the following 3 forces in a combined way:
1. the frequency converter controls the bucket opening motor to output a smaller moment threshold value N1;
2. the minimum moment required by the bucket opening motor to drive the winding drum to wind the steel wire rope is a first moment N2;
3. when the pushing mechanism works, the moment of the bucket on the steel wire rope is the second moment N3.
In system design, N1 is adjusted to a fixed value greater than N2.
N3 varies with the operation of the pressing mechanism:
when the pushing mechanism does not work, N3=0, N1 is larger than N2, and the winding drum normally winds the rope until the steel wire rope is tensioned;
when pushing forwards, N3 is far greater than N2, and the winding drum starts to passively unwind the rope until pushing stops;
when pushing backwards, N3<0, the steel wire rope starts to loosen, and the winding drum normally winds the rope until the steel wire rope is tensioned because N1> N2; thereby keeping the bucket opening rope to be rolled and unrolled along with the bucket.
The foregoing embodiments are directed to various embodiments, and details of one embodiment may be found in the related description of another embodiment.
The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A variable frequency hopper opening control system, comprising:
the power supply control unit is used for responding to the power supply running state, triggering a guy rope signal and outputting the guy rope signal;
the main command control unit is used for responding to a bucket opening operation instruction, triggering a bucket opening signal and outputting the bucket opening signal, wherein the output time of the bucket opening signal is later than that of the guy rope signal;
the frequency converter is electrically connected with a bucket opening motor and is used for receiving a guy rope signal, starting the frequency converter in response to the guy rope signal and outputting a preset first torque to the bucket opening motor until the bucket opening signal is received;
the frequency converter receives the opening signal, responds to the opening signal to increase the first torque to the second torque in a preset time period, and outputs the second torque to the opening motor so as to control the torque of the opening motor and open the hopper bolt.
2. The variable frequency hopper control system of claim 1 wherein the power control unit comprises a three-phase rectifier bridge power supply and a contactor, the three-phase rectifier bridge power supply being electrically connected to a coil of the contactor, an auxiliary contact of the contactor being electrically connected to a first end of the frequency converter.
3. The variable frequency hopper control system of claim 2 wherein the auxiliary contacts of the contactor are all normally open contacts.
4. The variable frequency hopper control system of claim 1, wherein the master control unit comprises a master switch, a first relay and a second relay, the master switch is electrically connected with a coil of the first relay, an auxiliary contact of the first relay is electrically connected with a coil of the second relay, and an auxiliary contact of the second relay is electrically connected with a second end of the frequency converter.
5. The variable frequency hopper control system of claim 4 wherein the auxiliary contacts of the first relay and the second relay are both normally open contacts.
6. The variable frequency hopper opening control system of claim 1 wherein an encoder is disposed within the hopper opening motor, the encoder being configured to collect the speed and direction of the hopper opening motor and transmit to the frequency converter.
7. The variable frequency hopper control system of claim 1 further comprising a braking resistor, a first end of the braking resistor being electrically connected to a third end of the frequency converter, a fourth end of the frequency converter being electrically connected to a second end of the braking resistor.
8. A variable frequency hopper opening control method, comprising:
acquiring a guy rope signal, responding to the guy rope signal, starting a frequency converter and outputting a preset first torque to the bucket opening motor until receiving the bucket opening signal;
responding to the first torque increased to the second torque by the bucket opening signal in a preset time period and outputting the second torque to the bucket opening motor so as to control the torque of the bucket opening motor and open a bucket bolt;
the guy rope signal is output by the power supply control unit in response to the power supply running state, and the bucket opening signal is triggered by the main control unit in response to the bucket opening running instruction.
9. The variable frequency hopper control method of claim 8 wherein the frequency converter controls the hopper motor to output a first torque and a second torque based on the first torque, the second torque being greater than the first torque, the first torque being greater than a torque threshold.
10. The variable frequency bucket opening control method of claim 8 wherein the preset time period is 1s to 2s, the first torque is 4% to 6% and the second torque is 55% to 65% torque.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311311384.4A CN117595745A (en) | 2023-10-10 | 2023-10-10 | Variable-frequency bucket opening control system and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311311384.4A CN117595745A (en) | 2023-10-10 | 2023-10-10 | Variable-frequency bucket opening control system and method |
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| Publication Number | Publication Date |
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| CN117595745A true CN117595745A (en) | 2024-02-23 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311311384.4A Pending CN117595745A (en) | 2023-10-10 | 2023-10-10 | Variable-frequency bucket opening control system and method |
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| CN (1) | CN117595745A (en) |
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2023
- 2023-10-10 CN CN202311311384.4A patent/CN117595745A/en active Pending
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