Load balance control system for double roller grinding device

Abstract

The present application discloses a load balancing control system for a double-roll grinding device, which includes a fixed roller and a floating roller, and the load balancing control system includes: a fixed roller driving device, which includes a fixed roller driving inverter and a fixed roller driving motor, wherein the fixed roller driving inverter is configured as a speed control mode; a floating roller driving device, which includes a floating roller driving inverter and a floating roller driving motor, wherein the floating roller driving inverter is configured as a speed control mode; a controller sends a main speed set value to the fixed roller driving inverter and the floating roller driving inverter respectively; a speed compensator obtains a current speed correction value based on a PID algorithm according to the current torque of the fixed roller driving motor and the current torque of the floating roller driving motor, and outputs the current speed correction value to the floating roller driving inverter; the floating roller driving inverter obtains a current adjustment speed based on the sum of the current speed correction value and the main speed set value Vset.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of double-roller grinding, and in particular to a load balancing control system for a double-roller grinding device. Background Art

[0002] Roller press is a grinding equipment for brittle materials, suitable for grinding cement clinker, cement raw materials (limestone, sandstone, etc.), gypsum, coal, quartz sand, iron ore, blast furnace slag and other materials. Roller press is mainly composed of feeding device, double roller grinding device, hydraulic system, lateral leakage prevention device and other parts. Double roller grinding device consists of two grinding rollers, one of which is fixed roller and the other is floating roller that can move in the horizontal direction, so that the gap between the two rollers can be controlled. Through the action of the hydraulic system, the floating roller can form a very high pressure between the two rollers, so as to crush and squeeze out the material. At present, the control method of double roller grinding device has the following problems:

[0003] 1) When the hydraulic system applies a large pressure to the floating roller or the system is stuck, the output of the two rollers will be unbalanced;

[0004] 2) The unbalanced force output of the two rollers will cause different wear on the rollers, and the different wear conditions will cause different roller diameters, which will further aggravate the difference in the linear speed of the two rollers.

[0005] 3) The output of the two rollers is unbalanced, resulting in uneven discharge, reduced grindability of the material, and increased energy consumption of subsequent equipment grinding mills.

[0006] 4) The unbalanced output of the two rollers will greatly increase the electrical noise of the roller press. Utility Model Content

[0007] In order to solve the above technical problems, the utility model provides a load balancing control system for a double-roller grinding device.

[0008] The present application provides a load balancing control system for a double-roll grinding device, wherein the double-roll grinding device comprises a fixed roller and a floating roller, and the load balancing control system comprises:

[0009] A fixed roller driving device, comprising a fixed roller driving inverter and a fixed roller driving motor, wherein the fixed roller driving inverter is configured in a speed control mode, and the fixed roller driving inverter outputs a current torque of the fixed roller driving motor to a speed compensator;

[0010] A floating roller driving device, comprising a floating roller driving inverter and a floating roller driving motor, wherein the floating roller driving inverter is configured in a speed control mode, and the floating roller driving inverter outputs a current torque of the floating roller driving motor to the speed compensator;

[0011] The controller sets the speed main given value V set The signals are sent to the fixed roller drive inverter and the floating roller drive inverter respectively;

[0012] The speed compensator obtains a current speed correction value based on the PID algorithm according to the current torque of the fixed roller drive motor and the current torque of the floating roller drive motor, and outputs the current speed correction value to the floating roller drive inverter; the floating roller drive inverter is based on the current speed correction value and the speed main setting value V set The sum of the values ​​obtained is the current adjustment speed, which makes the output torque of the floating roller drive motor consistent with the output torque of the fixed roller drive motor.

[0013] Optionally, the speed compensator outputs the speed correction value to an additional setpoint channel of a speed loop of a floating roller drive frequency converter.

[0014] Optionally, the current torque of the fixed roller output by the fixed roller drive inverter is the current torque setting value output by the speed loop controller of the fixed roller drive inverter, and the current torque of the floating roller output by the floating roller drive inverter is the current torque setting value output by the speed loop controller of the floating roller drive inverter.

[0015] Optionally, the speed compensator comprises a PID controller and a multiplier, wherein:

[0016] The PID controller obtains a current initial speed correction value based on a PID algorithm according to the current torque of the fixed roller drive motor and the current torque of the floating roller drive motor, and outputs the current initial speed correction value to the multiplier;

[0017] The multiplier multiplies the received current initial speed correction value by a preset proportionality coefficient to obtain the current speed correction value and outputs it to the speed loop additional set value channel of the floating roller drive inverter.

[0018] Optionally, the proportionality coefficient is between 1% and 10%.

[0019] Optionally, the speed compensator is disposed in the floating roller drive frequency converter.

[0020] Optionally, the analog output interface of the fixed roller driving inverter is connected to the analog input interface of the floating roller driving inverter via a twisted pair cable.

[0021] The positive and progressive effects of the utility model are:

[0022] The load balancing control system for a double-roll grinding device provided in the present application obtains a current speed correction value according to the difference between the current torque of the fixed roller drive motor and the current torque of the floating roller drive motor, and the speed correction value is used to be superimposed on the speed main setting value V of the floating roller drive inverter. set , thereby adjusting the speed of the floating roller drive motor to make the output torque of the floating roller drive motor consistent with the output torque of the fixed roller drive motor, thereby balancing the loads of the two rollers while ensuring the stable operation of the double-roller grinding device. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The following drawings are only intended to illustrate and explain the present application, and do not limit the scope of the present application.

[0024] Figure 1 A schematic diagram showing the principle of a load balancing control system of a double-roll grinding device according to an embodiment of the present application is shown;

[0025] Figure 2 A control schematic diagram of a load balancing control system for a double-roll grinding device according to an embodiment of the present application is shown;

[0026] Figure 3 A control schematic diagram of a load balancing control system for a double-roll grinding device according to another embodiment of the present application is shown.

[0027] Description of reference numerals:

[0028] 10: Controller;

[0029] 211: Fixed roller drive inverter;

[0030] 2111: Ramp function generator for fixed roller drive inverter;

[0031] 2112: Speed ​​loop controller for fixed roller drive inverter;

[0032] 2113: Current loop controller for fixed roller drive inverter;

[0033] 2114: PWM output of fixed roller drive inverter;

[0034] 212: fixed roller drive motor;

[0035] 221: floating roller drive inverter;

[0036] 2211: Ramp function generator for the floating roller drive inverter;

[0037] 2212: Speed ​​loop controller for floating roller drive inverter;

[0038] 2213: Current loop controller for floating roller drive inverter;

[0039] 2214: PWM output of the floating roller drive inverter;

[0040] 222: floating roller driving motor;

[0041] 31: fixed roller;

[0042] 32: floating roller;

[0043] 40: Hydraulic cylinder;

[0044] 50: feed hopper;

[0045] 60: Materials;

[0046] 70: speed compensator;

[0047] 71: PID controller;

[0048] 72: multiplier;

[0049] 911: Main given value V set ;

[0050] 912: Correcting the rotation speed of the floating roller drive motor according to the current torque of the fixed roller drive motor and the current torque of the floating roller drive motor;

[0051] 913: Current torque of the fixed roller drive motor;

[0052] 914: current torque of the floating roller drive motor;

[0053] 915: initial speed correction value;

[0054] 916: speed correction value; DETAILED DESCRIPTION

[0055] In order to have a clearer understanding of the technical features, purposes and effects of the embodiments of the present application, the specific implementation methods of the embodiments of the present application are now described with reference to the accompanying drawings.

[0056] Roller press is a grinding equipment for brittle materials, suitable for grinding cement clinker, cement raw materials (limestone, sandstone, etc.), gypsum, coal, quartz sand, iron ore, blast furnace slag and other materials. Roller press is mainly composed of feeding device, double roller grinding device, hydraulic system, lateral leakage prevention device and other parts. The double roller grinding device is composed of two grinding rollers, one of which is a fixed roller and the other is a floating roller that can move in the horizontal direction, so that the gap between the two rollers can be controlled. Through the action of hydraulic cylinder 40, the floating roller can form a very high pressure between the two rollers, so as to crush and extrude the material. The current control method of the double roller grinding device has the following problems:

[0057] 1) When the hydraulic system applies a large pressure to the floating roller or the system is stuck, the output of the two rollers will be unbalanced;

[0058] 2) The unbalanced force output of the two rollers will cause different wear on the rollers, and the different wear conditions will cause different roller diameters, which will further aggravate the difference in the linear speed of the two rollers.

[0059] 3) The output of the two rollers is unbalanced, resulting in uneven discharge, reduced grindability of the material, and increased energy consumption of subsequent equipment grinding mills.

[0060] 4) The unbalanced output of the two rollers will greatly increase the electrical noise of the roller press.

[0061] Based on the above problems, an embodiment of the present application provides a load balancing control system for a double-roller grinding device to at least partially solve the above technical problems.

[0062] The specific implementation of the embodiments of the present application is described in detail below with reference to the accompanying drawings.

[0063] like Figure 1 As shown, the double-roll grinding device includes a fixed roller 31 and a floating roller 32, wherein the floating roller 32 can move in the horizontal direction. During the operation of the double-roll grinding device, the two rollers rotate toward each other, and the hydraulic cylinder 40 acts on the floating roller 32 to form pressure between the two rollers, thereby crushing and squeezing the material. The load balancing control system for the double-roll grinding device includes a controller 10, a fixed roller driving device, a floating roller driving device, and a speed compensator 70. Figure 1 As shown, the fixed roller driving device includes a fixed roller driving inverter 211 and a fixed roller driving motor 212, and the floating roller driving device includes a floating roller driving inverter 221 and a floating roller driving motor 222, wherein the fixed roller driving inverter 211 and the floating roller driving inverter 221 are respectively configured in a speed control mode. Figure 2 As shown, the controller 10 transmits the speed main given value V through communication or analog quantity. setThe fixed roller drive inverter 211 and the floating roller drive inverter 221 are respectively sent to the fixed roller drive inverter 211 and the floating roller drive inverter 221. The two inverters pass through their respective ramp function generators RFG, speed loops, and current loops, and finally pass through the IGBT inverter output to achieve closed-loop speed control. The fixed roller drive inverter 211 outputs the current torque of the fixed roller drive motor 212 to the speed compensator 70, and the floating roller drive inverter 221 outputs the current torque of the floating roller drive motor 222 to the speed compensator 70. The speed compensator 70 processes the received current torque of the fixed roller and the current torque of the floating roller based on the PID algorithm to obtain the current speed correction value, and then outputs the current speed correction value to the floating roller drive inverter 221; the floating roller drive inverter 221 adjusts the speed based on the current speed correction value and the speed main setting value V set The sum of the values ​​of V and V is the current adjustment speed, which makes the output torque of the floating roller drive motor 222 consistent with the output torque of the fixed roller drive motor 212. The current speed correction value is superimposed on the speed main setting value V of the floating roller drive inverter 221. set The rotation speed of the floating roller driving motor 222 is adjusted so that the output torque of the floating roller driving motor 222 is consistent with the output torque of the fixed roller driving motor 212, thereby balancing the loads of the two rollers.

[0064] In order to improve the effect of the double-roll grinding device, the load of the fixed roller and the floating roller needs to be balanced, that is, the output torque of the floating roller drive motor 222 is consistent with the output torque of the fixed roller drive motor 212. However, there is no mechanical coupling relationship between the fixed roller and the floating roller. If the torque of the floating roller drive motor 222 is only controlled to make the torque of the floating roller drive motor 222 consistent with the torque of the fixed roller drive motor 212, when there is no material 60 between the fixed roller and the floating roller, or when the floating roller drive motor is broken, the torque of the floating roller drive motor 222 is only used for acceleration, and the speed of the floating roller drive motor 222 will suddenly increase, causing runaway, which has a great safety hazard.

[0065] The load balancing control system of the present application obtains a current speed correction value based on the difference between the current torque of the fixed roll and the current torque of the floating roll, and the speed correction value is used to be added to the speed main setting value V of the floating roll drive inverter. set, thereby adjusting the speed of the floating roller drive motor, and under the premise of ensuring the stable operation of the double-roller grinding device, making the output torque of the floating roller drive motor consistent with the output torque of the fixed roller drive motor, so that the load of the two rollers is balanced. Load balancing greatly improves the phenomenon of insufficient output on one side when the hydraulic cylinder pressure is high or the system is stuck. And avoids the phenomenon of different degrees of wear of the rollers caused by load imbalance, and different wear conditions will cause different roller diameters, which in turn cause different linear speeds of the two rollers. Therefore, the load balancing control system of the present application can ensure that the linear speeds of the two rollers are consistent, thereby greatly extending the service life of the roller wear-resistant layer. And load balancing, on the one hand, makes the discharge more uniform, improves the grindability of the material, and greatly reduces the energy consumption of the subsequent equipment grinding mill; on the other hand, it greatly reduces the electrical noise of the roller press, making mechanical and electrical maintenance very simple, reducing maintenance costs.

[0066] In one embodiment, the speed compensator 70 outputs the current speed correction value to the speed loop additional set value channel of the floating roller drive inverter 221 .

[0067] The speed compensator 70 outputs the speed correction value to the additional set value channel of the speed loop of the floating roller drive inverter 221, so that the speed correction value does not need to pass through the ramp function generator of the floating roller drive inverter 221. The speed loop of the floating roller drive inverter 221 directly responds after receiving the speed correction value, which greatly improves the response speed, thereby being able to timely correct the output torque of the floating roller drive motor 222.

[0068] In one embodiment, the current torque of the fixed roller output by the fixed roller drive inverter 211 is the current torque setting value output by the speed ring controller of the fixed roller drive inverter 211, and the current torque of the floating roller output by the floating roller drive inverter 221 is the current torque setting value output by the speed ring controller of the floating roller drive inverter 221.

[0069] This embodiment adjusts the speed of the floating roller drive motor based on the current torque setting value of the two rollers. Compared with the actual torque output value, the change frequency of the torque setting value output by the speed loop is lower, thereby reducing the calculation amount of the speed compensator. In addition, the actual torque output value has hysteresis, so the torque setting value output by the speed loop can be used for compensation in advance, thereby improving the control effect.

[0070] In one embodiment, if Figure 3As shown, the speed compensator 70 includes a PID controller 71 and a multiplier 72, wherein the PID controller 71 obtains a current initial speed correction value based on a PID algorithm according to the current torque of the fixed roller drive motor 212 and the current torque of the floating roller drive motor 222, and outputs the current initial speed correction value to the multiplier 72; the multiplier 72 multiplies the received initial speed correction value by a proportional coefficient to obtain a speed correction value and outputs it to the speed loop additional set value channel of the floating roller drive inverter 221.

[0071] In one embodiment, the proportionality factor is between 1% and 10%.

[0072] In this embodiment, through the multiplier 72, the speed compensator 70 fine-tunes the current speed of the floating roller motor based on the difference between the fixed roller torque and the floating roller torque to avoid sudden changes in the speed of the floating roller. Under the premise of ensuring the stable operation of the entire system, the load of the fixed roller and the floating roller is balanced.

[0073] In one embodiment, Figure 3 As shown, the speed compensator 70 is disposed in the floating roller drive inverter 221 .

[0074] The speed compensator 70 is arranged in the floating roller drive inverter 221, which can avoid the need to purchase a separate speed compensator 70, thus greatly saving hardware costs; and the driver has a fast refresh speed, which improves the compensation speed.

[0075] In one embodiment, the analog output interface of the fixed roller driving inverter 211 and the analog input interface of the floating roller driving inverter 221 are connected via a twisted pair cable.

[0076] The analog output interface of the fixed roller drive inverter 211 and the analog input interface of the floating roller drive inverter 221 are connected through a twisted pair cable, so that the torque setting value of the fixed roller drive inverter 211 can be directly sent to the speed compensator in the floating roller drive inverter 221, thereby avoiding the risk of shutdown due to failure of the upper control system or communication failure.

[0077] In other embodiments, the torque setting value of the fixed roller drive inverter can also be sent to the speed compensator in the floating roller drive inverter through a communication link of fixed roller drive inverter→controller→floating roller drive inverter.

[0078] Optionally, the speed compensator 70 may also be disposed in the controller 10 .

[0079] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0080] The above is only an illustrative specific implementation of the embodiment of the present application, and is not intended to limit the scope of the embodiment of the present application. Any equivalent changes, modifications and combinations made by any technician in this field without departing from the concept and principle of the embodiment of the present application should fall within the scope of protection of the embodiment of the present application.

Claims

1. A load balancing control system for a double-roll grinding device, the double-roll grinding device comprising a fixed roller (31) and a floating roller (32), characterized in that: The load balancing control system comprises: A fixed roller driving device, comprising a fixed roller driving inverter (211) and a fixed roller driving motor (212), wherein the fixed roller driving inverter (211) is configured in a speed control mode, and the fixed roller driving inverter (211) outputs a current torque of the fixed roller driving motor (212) to a speed compensator (70); A floating roller driving device, comprising a floating roller driving frequency converter (221) and a floating roller driving motor (222), wherein the floating roller driving frequency converter (221) is configured in a speed control mode, and the floating roller driving frequency converter (221) outputs the current torque of the floating roller driving motor (222) to the speed compensator (70); Controller (10), which sets the speed main given value V set Sending to the fixed roller drive frequency converter (211) and the floating roller drive frequency converter (221); The speed compensator (70) obtains a current speed correction value based on a PID algorithm according to the current torque of the fixed roller drive motor (212) and the current torque of the floating roller drive motor (222), and outputs the current speed correction value to the floating roller drive inverter (221); the floating roller drive inverter (221) adjusts the current speed correction value based on the current speed correction value and the speed main setting value V set The sum of the values ​​obtained is used to obtain the current adjustment speed, which makes the output torque of the floating roller drive motor (222) consistent with the output torque of the fixed roller drive motor (212).

2. The load balancing control system for a double-roll grinding device according to claim 1, characterized in that: The speed compensator (70) outputs the speed correction value to the speed loop additional set value channel of the floating roller drive inverter (221).

3. The load balancing control system for a double-roll grinding device according to claim 2, characterized in that: The current torque of the fixed roller output by the fixed roller drive inverter (211) is the current torque setting value output by the speed ring controller of the fixed roller drive inverter (211), and the current torque of the floating roller output by the floating roller drive inverter (221) is the current torque setting value output by the speed ring controller of the floating roller drive inverter (221).

4. The load balancing control system for a double-roll grinding device according to claim 3, characterized in that: The speed compensator (70) comprises a PID controller (71) and a multiplier (72), wherein: The PID controller (71) obtains a current initial speed correction value based on a PID algorithm according to the current torque of the fixed roller drive motor (212) and the current torque of the floating roller drive motor (222), and outputs the current initial speed correction value to the multiplier (72); The multiplier (72) multiplies the received current initial speed correction value by a preset proportionality coefficient to obtain a current speed correction value and outputs it to the speed loop additional set value channel of the floating roller drive inverter (221).

5. The load balancing control system for a double-roll grinding device according to claim 4, characterized in that: The proportionality factor is between 1% and 10%.

6. The load balancing control system for a double-roll grinding device according to claim 5, characterized in that: The speed compensator (70) is disposed in the floating roller drive frequency converter (221).

7. The load balancing control system for a double-roll grinding device according to claim 6, characterized in that: The analog output interface of the fixed roller driving frequency converter (211) and the analog input interface of the floating roller driving frequency converter (221) are connected via a twisted pair cable.

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