Multi-motor transmission straightener load distribution control method

Abstract

The invention discloses a multi-motor transmission straightener load distribution control method, which comprises the following steps of: correcting the speed of a rear motor on a straightener through a load balancer, and keeping the speed of the rear motor consistent with the speed of a front motor on the straightener; the load balancer takes the torque of the front motor as a reference value, the reference value is compared with an actual value of the torque of the rear motor, a speed correction value of the rear motor is obtained, and the speed correction value limits the speed of the rear motor in a speed window of the load balancer; and when the parameters of the front motor are the same as the parameters of the rear motor, the load distribution ratio of the load balancer is set to be 1. The problem of load distribution of straightening machine double-motor transmission is solved, and the speed stability of the straightening machine is guaranteed when abnormal conditions such as slipping occur.

Description

Technical Field

[0001] The invention relates to a 2050 hot rolling intensive heat treatment line technology, and more specifically to a load distribution control method for a multi-motor driven straightening machine. Background Art

[0002] The straightening machine at the entrance of the existing steel enterprise's 2050 hot rolling intensive heat treatment line is driven by dual motors, among which the front motor controls the 5 rollers at the entrance and the rear motor controls the 6 rollers at the exit. When the front and rear motors are both speed controlled, the uneven wear of the roller surface of the straightening rollers and uncontrollable factors such as the wave shape of the strip will cause the speed of the front and rear motors to mismatch, accelerate the wear of some working rollers, and even squeeze the working rollers in severe cases. The speed mismatch will also cause the front and rear motors to load each other, reduce the equipment capacity, and lead to mechanical decoupling of the entrance straightening machine.

[0003] In addition, since different incoming materials require different straightening roller gaps, if the roller gap difference at the entrance and exit is large, the torque distribution difference between the front and rear motors will also be large. If the control is not good, slight slippage may also occur. Summary of the invention

[0004] In view of the defects existing in the prior art, the purpose of the present invention is to provide a load distribution control method for a straightening machine with multi-motor transmission, so as to solve the load distribution problem of the straightening machine with dual motor transmission and ensure the speed stability of the straightening machine when abnormalities such as slipping occur.

[0005] To achieve the above object, the present invention adopts the following technical solution:

[0006] A load distribution control method for a straightening machine driven by multiple motors:

[0007] Correcting the speed of the rear motor on the straightener by means of a load balancer so that the speed of the rear motor is consistent with the speed of the front motor on the straightener;

[0008] The load balancer uses the torque of the front motor as a reference value and compares it with the actual value of the torque of the rear motor to obtain a speed correction value of the rear motor, and the speed correction value limits the speed of the rear motor within the speed window of the load balancer;

[0009] When the parameters of the front motor are the same as the parameters of the rear motor, the load distribution ratio of the load balancer is set to 1.

[0010] Preferably, the load balancer adopts a proportional control method.

[0011] Preferably, the input of the proportional control method of the load balancer is the actual torque of the front motor and the actual torque of the rear motor, and the output is the speed correction value of the rear motor.

[0012] Preferably, when the speed main setting of the rear motor + the speed correction value of the rear motor is greater than the actual speed value of the rear motor, the output of the rear motor = (torque setting - torque feedback) * proportional coefficient;

[0013] Otherwise, the output of the rear motor maintains the current value.

[0014] The present invention provides a load distribution control method for a straightening machine with multi-motor drive, which solves the load distribution problem of the dual-motor drive of the straightening machine and ensures the speed stability of the straightening machine when anomalies such as slippage occur (due to uneven wear of the roll necks of the straightening rolls and uncontrollable factors such as the wave shape of the strip, the front and rear speeds may not match, causing some working rolls to wear quickly, and in severe cases, the working rolls may be squeezed and damaged. The speed mismatch may also cause the front and rear motors to load each other, reducing the capacity of the equipment. Different incoming materials require different straightening roll gaps. If the difference in the inlet and outlet roll gaps is large, the torque distribution difference of the front and rear motors will also be large, and slight slippage may occur if the control is not good). At the same time, the roll consumption is effectively reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the principle of the load distribution control method of the straightening machine of the present invention;

[0016] Figure 2 It is a control schematic diagram of the load distribution control method of the straightening machine of the present invention. DETAILED DESCRIPTION

[0017] In order to better understand the above technical solution of the present invention, the technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0018] Combination Figure 1 , Figure 2 As shown, the present invention provides a multi-motor driven straightening machine load distribution control method:

[0019] The speed of the rear motor 2 on the straightening machine is corrected by the load balancer 1 so that the speed of the rear motor 2 is consistent with the speed of the front motor 3 on the straightening machine.

[0020] The load balancer 1 uses the torque of the front motor 3 as a reference value, and compares it with the actual value of the torque of the rear motor 2 to obtain a speed correction value of the rear motor 2. The speed correction value limits the speed of the rear motor 2 within the speed window of the load balancer 1. When the straightening machine slips, due to the limitation of the speed window, the rear motor 2 will be limited by the speed window to maintain the limited speed. In this way, even if the straightening machine has slipped, the speed of the rear motor 2 is still a stable speed without fluctuations, and will not affect the speed of the front motor 3.

[0021] The load balancer 1 adopts proportional control, because if proportional integral control is adopted, only static error can be eliminated. The output of the load balancer 1 in the present invention is given to the transmission device of the rear motor 2 as the speed added value of the rear motor 2, and the transmission device of the rear motor 2 already has an integral link before the speed adjustment. Therefore, the load balancer 1 in the present invention only needs to adopt proportional control to improve the response.

[0022] The inputs of the proportional control mode of the load balancer 1 are the actual torque of the front motor 3 (as the torque reference value of the rear motor 2), the actual torque of the rear motor 2 (as the actual torque feedback of the rear motor 2), the speed window (used to limit the upper and lower limit windows of the speed additional value of the rear motor 2), the KP value (the amplification factor of the load balancer 1, used to control the response of the load balancer 1), and the load distribution ratio (used to set the power ratio and torque ratio of the front motor 3 and the rear motor 2. If the parameters of the two motors are the same, it is set to 1). The output is the speed correction value of the rear motor 2. The PLC sends this speed additional value to the rear motor 2 as a correction to the speed setting.

[0023] When the speed main setting of the rear motor 2 + the speed correction value of the rear motor 2 is greater than the actual speed value of the rear motor 2, the output of the rear motor 2 = (torque setting - torque feedback) * proportional coefficient;

[0024] Otherwise, the output of the rear motor 2 maintains the current value.

[0025] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention, and are not intended to limit the present invention. As long as they are within the spirit of the present invention, any changes or modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. A load distribution control method for a straightening machine driven by multiple motors, characterized in that: Correcting the speed of the rear motor on the straightener by means of a load balancer so that the speed of the rear motor is consistent with the speed of the front motor on the straightener; The load balancer uses the torque of the front motor as a reference value and compares it with the actual value of the torque of the rear motor to obtain a speed correction value of the rear motor, and the speed correction value limits the speed of the rear motor within the speed window of the load balancer; When the parameters of the front motor are the same as the parameters of the rear motor, the load distribution ratio of the load balancer is set to 1.

2. The load distribution control method for a multi-motor driven straightening machine according to claim 1, characterized in that: The load balancer adopts a proportional control method.

3. The load distribution control method for a multi-motor driven straightening machine according to claim 2, characterized in that: The input of the proportional control method of the load balancer is the actual torque of the front motor and the actual torque of the rear motor, and the output is the speed correction value of the rear motor.

4. The load distribution control method for a straightening machine driven by multiple motors according to claim 3 is characterized in that: When the speed main setting of the rear motor + the speed correction value of the rear motor is greater than the actual speed value of the rear motor, the output of the rear motor = (torque setting - torque feedback) * proportional coefficient; Otherwise, the output of the rear motor maintains the current value.

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