A belt conveyor for main inclined shaft in a mine and its power balance adaptive control method

Abstract

This invention relates to a belt conveyor for a main inclined shaft in a mine and its power balance adaptive control method. The belt conveyor includes a head unloading drum, an intermediate unloading drum, and a tail drum. A conveying belt is wound around the head unloading drum, the intermediate unloading drum, and the tail drum. A head conveying section is formed between the head unloading drum and the intermediate unloading drum, and a tail conveying section is formed between the intermediate unloading drum and the tail drum. Downstream of the intermediate unloading drum, a first intermediate drive drum, a second intermediate drive drum, and a third intermediate drive drum are sequentially arranged below the tail conveying section. Downstream of the head unloading drum, a first head drive drum and a second head drive drum are sequentially arranged below the head conveying section. This invention can collaboratively control and maintain the power balance of the belt conveyor at over 95% throughout its entire life cycle.

Description

Technical Field

[0001] This invention relates to the field of belt conveyor technology, specifically to a main inclined shaft belt conveyor for mining and its power balance adaptive control method. Background Technology

[0002] The main inclined shaft belt conveyor is the main transportation artery in the coal mine. It is a high-power belt conveyor, and its transport capacity directly determines the output of the entire coal mining enterprise.

[0003] However, multi-point, multi-machine belt conveyors may experience limited conveying capacity due to excessively high or low operating current of a single motor, which could lead to equipment damage and affect production.

[0004] Excessive or insufficient operating current of the motor indicates power imbalance. After the conveyor drive rollers have been in operation for a period of time, one or more drive rollers may experience varying degrees of wear, leading to a significant difference in operating current between individual motors and other motors. This difference tends to widen as the conveying volume increases. Current technology can only ensure power balance during the commissioning of new equipment and cannot achieve power balance throughout the entire lifecycle of the belt conveyor. Summary of the Invention

[0005] In view of this, the present invention provides a main inclined shaft belt conveyor for mining and its power balance adaptive control method, thereby solving or at least alleviating one or more of the above-mentioned problems and other problems existing in the prior art.

[0006] To achieve the aforementioned objectives, a first aspect of the present invention provides a main inclined shaft belt conveyor for mining, wherein the belt conveyor includes a head unloading drum, an intermediate unloading drum, and a tail drum, and a conveying belt is wound on the head unloading drum, the intermediate unloading drum, and the tail drum. A head conveying section is formed between the head unloading drum and the intermediate unloading drum, and a tail conveying section is formed between the intermediate unloading drum and the tail drum. A first intermediate drive drum, a second intermediate drive drum, and a third intermediate drive drum are sequentially arranged downstream of the intermediate unloading drum and below the tail conveying section. A first head drive drum and a second head drive drum are sequentially arranged downstream of the head unloading drum and below the head conveying section.

[0007] In the belt conveyor as described above, optionally, the first head drive roller is located upstream of the second head drive roller, and the first head drive roller and the second head drive roller adopt a 2:1 power distribution arrangement, while the first intermediate drive roller, the second intermediate drive roller and the third intermediate drive roller adopt a 1:1:1 power distribution arrangement.

[0008] Optionally, in the belt conveyor described above, the belt conveyor has a control system, which includes a head control master station, a middle control substation, and a tail control substation. The head control master station, the middle control substation, and the tail control substation achieve control and signal acquisition through bus communication.

[0009] In the belt conveyor described above, optionally, the first head drive roller and the second head drive roller are located on the ground, while the first intermediate drive roller, the second intermediate drive roller, and the third intermediate drive roller are located underground in the coal mine. A belt scale is installed at the tail of the belt conveyor. The analog input / output module of the tail control substation reads the coal quantity from the belt scale through the belt scale controller. A tensioning device is installed at the head of the belt conveyor. The analog input / output module of the head control master station controls the tensioning device through the tensioning device controller. Furthermore, the head control master station adjusts the tension of the tensioning device according to a preset rule based on the coal quantity from the belt scale, the tension value of the tensioning device, and the current data of the motors at the first head drive roller, the second head drive roller, the first intermediate drive roller, the second intermediate drive roller, and the third intermediate drive roller. It also sends a speed compensation signal to the frequency converter with the largest current difference among the motors and maintains the power balance above 95%.

[0010] In the belt conveyor described above, optionally, the preset rule is:

[0011] Step S1: The machine head control master station controls the motor frequency converters of the first machine head drive roller, the second machine head drive roller, the first intermediate drive roller, the second intermediate drive roller and the third intermediate drive roller at a given standard speed;

[0012] Step S2: Real-time acquisition of the coal quantity of the belt scale, the tension value of the tensioning device, and the current value of the motor inverter;

[0013] Step S3: Using the average current value of the motor inverter as the reference current, compare the current value of each inverter with the reference current, save the data of the inverter with the worst power balance, and determine whether its ratio exceeds the preset power balance. If yes, proceed to step S4; otherwise, repeat step S3.

[0014] Step S4: Determine whether to adjust the belt tension based on the amount of coal on the belt scale and the tension of the tensioning device. If yes, proceed to step S5; otherwise, proceed to step S6.

[0015] Step S5: The analog input / output module of the machine head control master station outputs an analog transmission current signal to the tension controller of the tensioning device for tension adjustment;

[0016] Step S6: Perform speed setpoint compensation on the inverter with the worst power balance, and determine whether the power balance of the inverter with the worst power balance is better than the previous power balance. If yes, proceed to step S7; otherwise, proceed to step S9.

[0017] Step S7: Determine whether the power balance of the inverter with the worst power balance meets the balance requirements. If yes, complete this adjustment; otherwise, proceed to step S8.

[0018] Step S8: Repeat step S6 until the power balance of the inverter with the worst power balance meets the power balance requirement or the power balance is worse than the previous data.

[0019] Step S9: The machine head control master station controls the inverter with the worst power balance according to the given standard speed plus compensation speed, and restores the previous adjustment.

[0020] In the belt conveyor as described above, optionally, in step S6, the speed setpoint compensation is controlled by the head control master station according to the given standard speed minus the compensation speed, and the frequency converter with the worst power balance is controlled for 20 seconds.

[0021] To achieve the aforementioned objectives, a second aspect of the present invention provides a power balance adaptive control method for a belt conveyor, wherein the belt conveyor includes a head unloading roller, an intermediate unloading roller, and a tail roller; a conveying belt is wound around the head unloading roller, the intermediate unloading roller, and the tail roller; a head conveying section is formed between the head unloading roller and the intermediate unloading roller; a tail conveying section is formed between the intermediate unloading roller and the tail roller; a first intermediate drive roller, a second intermediate drive roller, and a third intermediate drive roller are sequentially arranged downstream of the intermediate unloading roller and below the tail conveying section; a first head drive roller and a second head drive roller are sequentially arranged downstream of the head unloading roller and below the head conveying section; the first head drive roller is located upstream of the second head drive roller; a belt scale is provided at the tail of the belt conveyor; and a tensioning device is provided at the head of the belt conveyor.

[0022] Furthermore, the belt conveyor has a control system, which includes a head control master station, a mid-machine control substation, and a tail control substation. The head control master station, the mid-machine control substation, and the tail control substation communicate to achieve control and signal acquisition. The analog input / output module of the tail control substation reads the coal quantity from the belt scale through the belt scale controller. The analog input / output module of the head control master station controls the tensioning device through the tensioning device controller.

[0023] The method includes the following steps:

[0024] Step S1: The machine head control master station controls the motor frequency converters of the first machine head drive roller, the second machine head drive roller, the first intermediate drive roller, the second intermediate drive roller and the third intermediate drive roller at a given standard speed;

[0025] Step S2: Real-time acquisition of the coal weighing amount of the belt scale, the tension value of the tensioning device, and the current value of the motor frequency converter;

[0026] Step S3: Using the average current value of the motor inverter as the reference current, compare the current value of each inverter with the reference current, save the data of the inverter with the worst power balance, and determine whether its ratio exceeds the preset power balance. If yes, proceed to step S4; otherwise, repeat step S3.

[0027] Step S4: Determine whether to adjust the belt tension based on the amount of coal on the belt scale and the tension value of the tensioning device. If yes, proceed to step S5; otherwise, proceed to step S6.

[0028] Step S5: The analog output of the machine head control master station is 4-20mA current signal to the tension controller of the tensioning device for tension adjustment;

[0029] Step S6: Perform speed setpoint compensation on the inverter with the worst power balance, and determine whether the power balance of the inverter with the worst power balance is better than the previous power balance. If yes, proceed to step S7; otherwise, proceed to step S9.

[0030] Step S7: Determine whether the power balance of the inverter with the worst power balance meets the balance requirements. If yes, complete this adjustment; otherwise, proceed to step S8.

[0031] Step S8: Repeat step S6 until the power balance of the inverter with the worst power balance meets the power balance requirement or the power balance is worse than the previous data.

[0032] Step S9: The machine head control master station controls the inverter with the worst power balance according to the given standard speed plus compensation speed, and restores the previous adjustment.

[0033] In the method described above, optionally, in step S6, the speed setpoint compensation is controlled by the machine head control master station according to the given standard speed minus the compensation speed, and the frequency converter with the worst power balance is controlled for 20 seconds.

[0034] Optionally, in the method described above, the first head drive roller is located upstream of the second head drive roller, and the first head drive roller and the second head drive roller are arranged in a 2:1 power distribution ratio, while the first intermediate drive roller, the second intermediate drive roller and the third intermediate drive roller are arranged in a 1:1:1 power distribution ratio.

[0035] In the aforementioned method, optionally, the head control master station adjusts the tension value of the tensioning device according to the coal weighing amount of the belt, the tension value of the tensioning device, and the current data of the motors at the first head drive roller, the second head drive roller, the first intermediate drive roller, the second intermediate drive roller, and the third intermediate drive roller, according to a preset rule, and sends a speed setpoint compensation signal to the frequency converter with the largest current difference among the motors, and keeps the power balance above 95%.

[0036] This invention provides a main inclined shaft belt conveyor for mining and its power balance adaptive control method. The control system adjusts the tension of the tensioning device and compensates for the worst-balanced speed of the frequency converter according to preset rules based on the acquired coal weighing volume, tension value of the tensioning device, and current value of the high-voltage frequency converter, achieving a motor power balance of no less than 95%. This power balance adaptive method for the belt conveyor is applied throughout the entire equipment lifecycle, effectively ensuring the coal mine output of the belt conveyor. Attached Figure Description

[0037] The disclosure of this invention will become more apparent from the accompanying drawings. It should be understood that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. In the drawings:

[0038] Figure 1 This is a schematic diagram of a structure of an embodiment of the main inclined shaft belt conveyor of the present invention;

[0039] Figure 2 This is a flowchart illustrating an embodiment of the power balance adaptive control method of the present invention.

[0040] Reference numerals: 1-Unloading roller at the machine head, 2-First machine head drive roller, 3-Second machine head drive roller, 4-First redirecting roller, 5-Second redirecting roller, 6-Intermediate unloading roller, 7-Second intermediate drive roller, 8-First intermediate drive roller, 9-Third intermediate drive roller, 10-Tail roller, 11-Belt scale, 12-Tensioning device. Detailed Implementation

[0041] Referring to the accompanying drawings and specific embodiments, the structure, composition, features, and advantages of the mine main inclined shaft belt conveyor and its power balance adaptive control method of the present invention will be described below by way of example. However, all descriptions should not be construed as limiting the present invention in any way.

[0042] Furthermore, for any single technical feature described or implied in the embodiments mentioned herein, or any single technical feature shown or implied in the various figures, the present invention still allows for any combination or deletion of these technical features (or their equivalents) without any technical obstacle, and thus these further embodiments according to the present invention should also be considered within the scope of this description.

[0043] It should also be noted that the terms "below" and "downstream" indicate the orientation or positional relationship based on the orientation or positional relationship of the main inclined shaft belt conveyor shown in the accompanying drawings and the direction of belt operation. They are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this disclosure.

[0044] Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of those features.

[0045] Figure 1 This is a schematic diagram of a structure of an embodiment of the main inclined shaft belt conveyor of the present invention.

[0046] like Figure 1As shown, the main inclined shaft belt conveyor may include a head unloading drum 1, a first head drive drum 2, a second head drive drum 3, a first redirecting drum 4, a second redirecting drum 5, an intermediate unloading drum 6, a first intermediate drive drum 8, a second intermediate drive drum 7, a third intermediate drive drum 9, a tail drum 10, a belt scale 11, and a tensioning device 12. The head drive section, consisting of the first head drive drum 2 and the second head drive drum 3, can be located on the ground, while the intermediate drive section, consisting of the first intermediate drive drum 8, the second intermediate drive drum 7, and the third intermediate drive drum 9, can be located underground in the coal mine. This arrangement allows the distance between the head drive section and the intermediate drive section to be greater than 2000 meters, making it suitable for complex terrain applications and enabling long-distance transport. In this embodiment, the distance is approximately 2100 meters. In other optional embodiments, those skilled in the art can set the distance between the head drive section and the intermediate drive section according to the actual working environment.

[0047] Specifically, belts for conveying coal are wound around the head unloading drum 1, the intermediate unloading drum 6, and the tail drum 10. The head conveying section is formed between the head unloading drum 1 and the intermediate unloading drum 6, and the tail conveying section is formed between the intermediate unloading drum 6 and the tail drum 10.

[0048] Downstream of the intermediate unloading roller 6, a first intermediate drive roller 8, a second intermediate drive roller 7, and a third intermediate drive roller 9 are sequentially arranged below the tail conveyor section. Downstream of the head unloading roller 1, a first redirecting roller 4, a first head drive roller 2, a second head drive roller 3, and a second redirecting roller 5 are sequentially arranged below the head conveyor section. The first redirecting roller 4 and the second redirecting roller 5 are located below the head conveyor section. Specifically, the first redirecting roller 4 is located downstream of the head unloading roller 1, the first head drive roller 2 is located downstream of the first redirecting roller 4, the second head drive roller 3 is located downstream of the first head drive roller 2, and the second redirecting roller 5 is located downstream of the second head drive roller 3.

[0049] In this embodiment, two motors can be connected to both sides of the first head drive roller 2 via shafts, and one motor can be connected to the second head drive roller 3 via a shaft. The first intermediate drive roller 8, the second intermediate drive roller 7, and the third intermediate drive roller 9 can each be connected to a motor via a shaft, resulting in a total of six motors in the entire belt conveyor. Each motor is equipped with its own frequency converter, and all six frequency converters have the same initial power. Furthermore, the first head drive roller 2 and the second head drive roller 3 are arranged in a 2:1 power distribution ratio, while the first intermediate drive roller 8, the second intermediate drive roller 7, and the third intermediate drive roller 9 are arranged in a 1:1:1 power distribution ratio. It should be noted that in this embodiment, frequency converters with the same power but different numbers are used to achieve the power distribution arrangement. In other optional embodiments, those skilled in the art can implement the power distribution arrangement in other ways, and the specific power distribution ratio can be set according to actual working needs.

[0050] The redirecting rollers 4 and 5 are mainly used to change the running direction of the conveyor belt. Additionally, they can be used to tighten the conveyor belt, increasing the wrap angle between it and the drive rollers 2 and 3. Because slippage easily occurs between the conveyor belt and the drive rollers 2 and 3, it can cause wear on the conveyor belt's coating, and in severe cases, lead to belt burnout or even a fire. Therefore, in this embodiment, two redirecting rollers 4 and 5 are added near the drive rollers 2 and 3. The belt conveyor can change its conveying direction by changing the rotation of the first redirecting roller 4 and the second redirecting roller 5, effectively preventing belt slippage.

[0051] In this embodiment, the belt conveyor may also have a control system. Specifically, the control system may include a head control master station, a mid-machine control substation, and a tail control substation. The head control master station, the mid-machine control substation, and the tail control substation communicate via a bus to achieve control and signal acquisition. Analog input / output modules are respectively provided in the head control master station, the mid-machine control substation, and the tail control substation. These analog input / output modules are used for data acquisition and control. Each module may include one or more analog input channels, which can convert signals from sensors, such as the belt scale 11 and the tensioning device 12 in this embodiment, into digital signals for processing within the control system. Similarly, the analog output channels can convert digital signals into electrical signals from the control system, outputting controllable analog transmission current and sending it to the frequency converter to control the corresponding actuator, such as the tensioning device 12 or the motor.

[0052] In this embodiment, the three components communicate via a ProfiBus bus and respectively acquire data from the belt scale 11 and the tensioning device 12. In other optional embodiments, those skilled in the art can select other buses for communication according to actual needs.

[0053] Specifically, in such Figure 1 In the illustrated embodiment, the analog input / output module of the tail control substation reads the coal quantity of the belt scale 11 located at the tail of the belt conveyor in real time through the belt scale controller. The analog input / output module of the head control master station controls the tensioning device 12 located at the head of the belt conveyor through the tensioning device controller. In this embodiment, the belt scale 11 is an explosion-proof electronic belt scale. In other optional embodiments, those skilled in the art can adjust the specific deployment positions and selected models of the belt scale 11 and the tensioning device 12 according to the actual working conditions.

[0054] In this embodiment, all six frequency converters are located in a ground-based frequency converter room. The ground-based frequency converter room is approximately 2180 meters away from the intermediate unloading drum 6. The high-voltage frequency converter can provide long-distance power to the first head drive drum 2, the second head drive drum 3, the first intermediate drive drum 8, the second intermediate drive drum 7, and the third intermediate drive drum 9. In this embodiment, the frequency converter is a Siemens Robicon, with an input voltage of 10kV and an output voltage of 6kV. In other optional embodiments, those skilled in the art can adjust the number of high-voltage frequency converters, the model of the frequency converters, and the distance between the ground-based frequency converter room and the intermediate unloading drum 6 according to actual working needs and the environment.

[0055] Furthermore, the high-voltage frequency converter can also adjust the power balance of the six motors mentioned above. Specifically, each motor corresponds to the adjustment and control of the power of one high-voltage frequency converter. The head control station adjusts the tension of the tensioning device 12 according to preset rules based on the coal weighing amount on the belt, the tension value of the tensioning device 12, and the current data of the motors at the first head drive roller 2, the second head drive roller 3, the first intermediate drive roller 8, the second intermediate drive roller 7, and the third intermediate drive roller 9. It also sends a speed compensation signal to the frequency converter with the largest current difference among the motors, minimizing the current difference between the frequency converters and thus achieving power balance among the motors. The specific preset rules and control methods will be explained in detail below and will not be elaborated upon here. The power balance between the motors can be adaptively controlled and maintained above 95% throughout the entire life cycle of the belt conveyor.

[0056] Figure 2 This is a flowchart illustrating an embodiment of the power balance adaptive control method of the present invention.

[0057] The inverters 1#-6# in the diagram are the six inverters corresponding to the six motors mentioned above.

[0058] This invention provides a power balance adaptive control method for belt conveyors, wherein the components and connections between the belt conveyor components are shown in [the following text is incomplete and requires further context]. Figure 1 The embodiments have been described in detail and will not be repeated here.

[0059] The power balance adaptive control method for belt conveyors, namely the preset rules mentioned above, can specifically include the following steps:

[0060] Step S1: The machine head control master station controls the motor frequency converters of the first machine head drive roller 2, the second machine head drive roller 3, the first intermediate drive roller 8, the second intermediate drive roller 7 and the third intermediate drive roller 9 at a given standard speed;

[0061] Step S2: Real-time acquisition of the coal weighing volume of the belt scale 11, the tension value of the tensioning device 12, and the current value of the motor frequency converter;

[0062] Step S3: Using the average current value of the motor inverter as the reference current, compare the current value of each inverter with the reference current, save the data of the inverter with the worst power balance, and determine whether its ratio exceeds the preset power balance. If yes, proceed to step S4; otherwise, repeat step S3.

[0063] Step S4: Determine whether to adjust the belt tension based on the amount of coal weighed by the belt scale 11 and the tension force of the tensioning device 12. If yes, proceed to step S5; otherwise, proceed to step S6.

[0064] Step S5: The analog input / output module of the machine head control master station outputs an analog transmission current signal to the tension controller of the tensioning device 12 for tension adjustment;

[0065] Step S6: Perform speed setpoint compensation on the inverter with the worst power balance, and determine whether the power balance of the inverter with the worst power balance is better than the previous power balance. If yes, proceed to step S7; otherwise, proceed to step S9.

[0066] Step S7: Determine whether the power balance of the inverter with the worst power balance meets the balance requirements. If yes, complete this adjustment; otherwise, proceed to step S8.

[0067] Step S8: Repeat step S6 until the power balance of the inverter with the worst power balance meets the power balance requirement or the power balance is worse than the previous data.

[0068] Step S9: The machine head control master station controls the inverter with the worst power balance according to the given standard speed plus compensation speed, and restores the previous adjustment.

[0069] In this embodiment, step S1 is initiated at 100% standard speed, and the frequency converter adjusts the power balance according to its own "droop control" function. The preset power balance mentioned in step S3 can be set differently by those skilled in the art in other optional embodiments, depending on different circumstances.

[0070] In this embodiment, in step S5, the analog output current of the generator head control master station is between 4-20mA, and the corresponding current value is compensated based on the current value of the inverter with the worst power balance. In this embodiment, the range of analog output current used is to reduce the error caused by the power balance adjustment of the inverter. In other optional embodiments, those skilled in the art can set the range of analog output current according to actual needs.

[0071] In step S6, the speed compensation is sent from the main control station of the generator head to the inverter with the worst power balance by subtracting the compensation speed from the given standard speed, with a delay of 20 seconds. In this embodiment, the compensation speed is set to 0.1% of the standard speed. In other optional embodiments, those skilled in the art can select different percentages of the standard speed and the delay duration for sending the compensation according to different situations.

[0072] In summary, this invention uses controllers such as belt scale controllers and tensioning device controllers to coordinate with tensioning device 12 to control and adjust the given speeds of multiple frequency converters, thereby achieving a power balance of over 95% for the belt conveyor. It also employs long-distance power supply technology for frequency converters, which is used throughout the entire life cycle of the belt conveyor, thus improving the conveying capacity of the belt conveyor.

[0073] The technical scope of this invention is not limited to the contents of the above specification. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this invention, and all such modifications and variations should fall within the scope of this invention.

Claims

1. A mine main slope belt conveyor, characterized in that, The belt conveyor comprises a head unloading roller (1), an intermediate unloading roller (6), a tail roller (10), a first redirection roller (4) and a second redirection roller (5), a belt is wound on the head unloading roller (1), the intermediate unloading roller (6) and the tail roller (10) for conveying, a head conveying section is formed between the head unloading roller (1) and the intermediate unloading roller (6), a tail conveying section is formed between the intermediate unloading roller (6) and the tail roller (10), and a first intermediate driving roller (8), a second intermediate driving roller (7) and a third intermediate driving roller (9) are sequentially arranged downstream of the intermediate unloading roller (6) and below the tail conveying section, and a first redirection roller (4), a first head driving roller (2), a second head driving roller (3) and a second redirection roller (5) are sequentially arranged downstream of the head unloading roller (1) and below the head conveying section; The belt conveyor has a control system, which comprises a head control master station, an intermediate control substation and a tail control substation, and the head control master station, the intermediate control substation and the tail control substation realize control and signal acquisition through bus communication; The first head driving roller (2) and the second head driving roller (3) are located on the ground, the first intermediate driving roller (8), the second intermediate driving roller (7) and the third intermediate driving roller (9) are located underground, a belt scale (11) is arranged at the tail of the belt conveyor, an analog input and output module of the tail control substation reads the belt scale coal quantity of the belt scale (11) through a belt scale controller, a tensioning device (12) is arranged at the head of the belt conveyor, an analog input and output module of the head control master station controls the tensioning device (12) through a tensioning device controller, and the head control master station adjusts the tensioning force of the tensioning device (12) according to the belt scale coal quantity, the tension value of the tensioning device (12), the current data of the motors at the first head driving roller (2), the second head driving roller (3), the first intermediate driving roller (8), the second intermediate driving roller (7) and the third intermediate driving roller (9), sends a speed given compensation signal to the frequency converter with the largest current difference in the motor and makes the power balance keep above 95%; The preset rule is as follows: Step S1: The head control master station controls the motor frequency converters of the first head driving roller (2), the second head driving roller (3), the first intermediate driving roller (8), the second intermediate driving roller (7) and the third intermediate driving roller (9) according to a given standard speed; Step S2: Real-time acquisition of the belt scale coal quantity of the belt scale (11), the tension value of the tensioning device (12) and the current value of the motor frequency converter is performed. Step S3: comparing the current value of each frequency converter with the average current value of the motor frequency converter as the reference current, saving the frequency converter data with the worst power balance degree, and determining whether the ratio exceeds the preset power balance degree, yes to step S4, otherwise repeat step S3; Step S4: determining whether to adjust the belt tension according to the belt scale coal quantity of the belt scale (11) and the tension of the tensioning device (12), yes to step S5, otherwise to step S6; Step S5: the analog quantity input and output module of the head control master station outputs an analog quantity transmission current signal to the tensioning device controller of the tensioning device (12) for tension adjustment; Step S6: compensating the speed given to the frequency converter with the worst power balance degree, and determining whether the power balance degree of the frequency converter with the worst power balance degree is better than the previous power balance degree, yes to step S7, otherwise to step S9; Step S7: determining whether the power balance degree of the frequency converter with the worst power balance degree meets the balance degree requirement, yes to complete the adjustment, otherwise to step S8; Step S8: repeating step S6 until the power balance degree of the frequency converter with the worst power balance degree meets the power balance requirement or is worse than the previous data; Step S9: the head control master station controls the frequency converter with the worst power balance degree according to the given standard speed plus compensation speed, and restores the previous adjustment.

2. The belt conveyor of claim 1, wherein, The first head drive roller (2) is located upstream of the second head drive roller (3), and the first head drive roller (2) and the second head drive roller (3) adopt a 2:1 power distribution arrangement, and the first intermediate drive roller (8), the second intermediate drive roller (7) and the third intermediate drive roller (9) adopt a 1:1:1 power distribution arrangement.

3. The belt conveyor of claim 1, wherein, In step S6, the speed given compensation is controlled by the head control master station according to the given standard speed minus compensation speed to control the frequency converter with the worst power balance degree, with a delay of 20 seconds.

4. A power balance adaptive control method for a belt conveyor, characterized by, The belt conveyor comprises a head unloading roller (1), an intermediate unloading roller (6) and a tail roller (10), a belt for conveying is wound on the head unloading roller (1), the intermediate unloading roller (6) and the tail roller (10), a head conveying section is formed between the head unloading roller (1) and the intermediate unloading roller (6), a tail conveying section is formed between the intermediate unloading roller (6) and the tail roller (10), and a first intermediate driving roller (8), a second intermediate driving roller (7) and a third intermediate driving roller (9) are sequentially arranged downstream of the intermediate unloading roller (6) and below the tail conveying section, a first head driving roller (2) and a second head driving roller (3) are sequentially arranged downstream of the head unloading roller (1) and below the head conveying section, the first head driving roller (2) is upstream of the second head driving roller (3), a belt scale (11) is arranged at the tail of the belt conveyor, and a tensioning device (12) is arranged at the head of the belt conveyor, The belt conveyor has a control system, the control system comprises a head control master station, an intermediate control substation and a tail control substation, the head control master station, the intermediate control substation and the tail control substation realize communication control and signal acquisition, an analog input and output module of the tail control substation reads the belt scale coal quantity of the belt scale (11) through a belt scale controller, and an analog input and output module of the head control master station controls the tensioning device (12) through a tensioning device controller, The method comprises the following steps: Step S1: The head control master station controls motor frequency converters of the first head driving roller (2), the second head driving roller (3), the first intermediate driving roller (8), the second intermediate driving roller (7) and the third intermediate driving roller (9) according to a given standard speed. Step S2: Real-time acquisition of belt scale coal quantity of the belt scale (11), tension value of the tensioning device (12) and current value of the motor frequency converter. Step S3: Taking the average value of the current value of the motor frequency converter as a reference current, comparing the current value of each frequency converter with the reference current, saving frequency converter data with the worst power balance degree, and judging whether the ratio exceeds a preset power balance degree. Step S4: According to the belt scale coal quantity of the belt scale (11) and the tension value of the tensioning device (12), judging whether to adjust the belt tension. Step S5: The head control master station outputs a 4-20mA current signal to the tensioning device controller of the tensioning device (12) to adjust the tension. Step S6: speed given compensation is made to the frequency converter with the worst power balance, and it is determined whether the power balance of the frequency converter with the worst power balance is better than the last power balance, if yes, proceed to step S7, otherwise proceed to step S9; Step S7: it is determined whether the power balance of the frequency converter with the worst power balance meets the balance requirement, if yes, the current adjustment is completed, otherwise proceed to step S8; Step S8: repeat step S6 until the power balance of the frequency converter with the worst power balance meets the power balance requirement or is worse than the last data; Step S9: the head control master station controls the frequency converter with the worst power balance according to the given standard speed plus compensation speed, and restores the previous adjustment.

5. The method of claim 4, wherein, In step S6, the speed given compensation is made by the head control master station controlling the frequency converter with the worst power balance according to the given standard speed minus compensation speed, and the delay is 20 seconds.

6. The method of claim 5, wherein, The first head drive roller (2) is located upstream of the second head drive roller (3), and the first head drive roller (2) and the second head drive roller (3) adopt a power distribution arrangement of 2:1, and the first intermediate drive roller (8), the second intermediate drive roller (7) and the third intermediate drive roller (9) adopt a power distribution arrangement of 1:1:

1.

7. The method of claim 6, wherein, The head control master station adjusts the tension value of the tensioning device (12) according to the belt scale coal quantity, the tension value of the tensioning device (12), the current data of the motors at the first head drive roller (2), the second head drive roller (3), the first intermediate drive roller (8), the second intermediate drive roller (7) and the third intermediate drive roller (9), and sends a speed given compensation signal to the frequency converter with the largest current difference in the motor and keeps the power balance above 95%.

Images