A method for implementing a system for regulating the load of a tension roller motor as a function of temperature

Abstract

The present application relates to a kind of system and implementation method for adjusting tension roller motor load according to temperature, including frequency converter, tension roller motor, PLC control module and temperature measuring element;The temperature measuring element is installed on the tension roller motor and is connected to the PLC control module, for the collection of tension roller motor temperature;The control unit of the frequency converter is communicated with the PLC control module by network, for receiving the control word sent by PLC control module, for driving the three-phase asynchronous motor;The tension roller motor is connected to the output end of the frequency converter, for executing the speed and torque instruction issued by frequency converter;The PI controller load coefficient of the tension roller motor is connected to the control word of the PLC control module, for obtaining load distribution coefficient by temperature calculation in the PLC control module, to be fed back to the frequency converter.The present application can avoid the problem that individual motor temperature rises faster, causing production line to be unable to normal production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cold rolling equipment, in particular to a system for adjusting motor load of tension roller according to temperature and an implementation method. BACKGROUND

[0002] The tension roller is an important part of the continuous cold rolling production line, and each set of tension roller is generally composed of 2 to 4 frequency conversion motors. The temperature of each motor is not the same due to the influence of external environment. In the continuous cold rolling production line, the load coefficient of the tension roller motor in the frequency conversion transmission system is defaulted as 1, and cannot be dynamically distributed according to the actual temperature of the motor. When the temperature of one of the motors reaches the alarm temperature, the production line cannot continuously produce at high speed, especially in the process of producing high-strength steel strips. When there is a motor with poor heat dissipation in the same set of tension rollers, the temperature rise of the motor will be significantly higher than that of other motors, which seriously restricts the stability of the continuous production of the production line. SUMMARY

[0003] The present application aims to provide a system for adjusting motor load of tension roller according to temperature, which can avoid the problem of rapid temperature rise of individual motors and cause the production line to be unable to produce normally.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a system for adjusting motor load of tension roller according to temperature, characterized by comprising a frequency converter, a tension roller motor, a PLC control module and a temperature measuring element.

[0005] The temperature measuring element is installed on the tension roller motor and connected to the PLC control module, and is used for collecting the temperature of the tension roller motor.

[0006] The control unit of the frequency converter is connected to the PLC control module through a network, and is used for receiving the control word sent by the PLC control module and driving the three-phase asynchronous motor.

[0007] The tension roller motor is connected to the output end of the frequency converter, and is used for executing the speed and torque instructions sent by the frequency converter.

[0008] The PI controller of the tension roller motor is connected to the control word of the PLC control module at the load coefficient, and is used for calculating the load coefficient through the temperature in the PLC control module, and feeding back to the frequency converter.

[0009] Further, one temperature measuring element is installed on the front bearing of the tension roller motor, three temperature measuring elements are installed on different parts of the stator of the tension roller motor, and one temperature measuring element is installed on the rear bearing of the tension roller motor.

[0010] Further, the PLC control module comprises an RTD module, a setting variable module, a temperature calculation module and a load coefficient calculation module, the RTD module is used for interfacing with the temperature measuring element and receiving temperature data, the setting variable module is used for setting input, output and intermediate variables, the input variables include whether the load automatic adjustment function is put into operation, the number of tension roller motors, motor temperature detection values and load coefficient limits, the output variables include the load coefficient of each three-phase asynchronous motor, and the intermediate variables include the calculation temperature intermediate process quantity; the motor temperature detection values in the setting variable module are filled in the temperature data received by the RTD module, the motor temperature detection values in the setting variable module and the number of tension roller motors are calculated by the temperature calculation module to obtain the calculation temperature intermediate process quantity, and the calculation temperature intermediate process quantity is calculated by the load coefficient calculation module to obtain the load coefficient of the tension roller motor.

[0011] Further, the tension roller motor is a three-phase asynchronous motor.

[0012] Another object of the present application is to provide an implementation method capable of better facilitating the operation of the system for adjusting the load of the tension roller motor according to the temperature.

[0013] The method comprises the following steps:

[0014] Step S1, the temperature measuring element collects the temperature of the tension roller motor and uploads to the PLC control module;

[0015] Step S2, the PLC control module performs temperature calculation on the temperature data collected by the temperature measuring element, obtains the load coefficient and feeds back to the frequency converter;

[0016] Step S3, the frequency converter executes the speed and torque instructions issued according to the load coefficient to the tension roller motor.

[0017] Further, the temperature calculation in step S2 is specifically weighted average calculation of the temperature of each tension roller motor according to the feedback values of the temperature measuring element to obtain the calculation temperature.

[0018] The calculation temperature formula is: t = [(T1+T2+T3+…+Tn)*50%+T1*30%+T2*20%] / n. n n+1 n+2

[0019] Wherein, t represents the temperature of the tension roller motor, n represents the number of temperature measuring elements distributed on the stator of the tension roller motor; Tn represents the temperature collected by the temperature measuring element at the nth position of the stator of the tension roller motor; T1 represents the temperature collected by the temperature measuring element at the front bearing of the tension roller motor. n n+1 n+2 ​​​​​Temperature collected by temperature measuring element in front bearing of tension roller motor.

[0020] Further, the load coefficient in the step S2 is specifically obtained by adjusting the load coefficient through the proportion of the calculated temperature deviation between each tension roller motor.

[0021] The load coefficient calculation formula is: C n =1+1 / n-t n / (t1+t2+……+t n );

[0022] Wherein, C n represents the load coefficient of the nth tension roller motor; n represents n tension roller motors; t n represents the temperature of the nth tension roller motor.

[0023] The beneficial effects of the present application: the present application aims at the frequent alarm of the tension roller motor temperature during the continuous high-strength work of the production line, which affects the stable operation of the production line and the service life of the motor. According to the difference of the temperature of each tension roller motor, the load distribution of each tension roller motor is adjusted, so that the temperature reaches dynamic balance, and the ability of the production line to continuously produce high-strength products for a long time is improved, so as to avoid the problem that the temperature of individual motor rises too fast, causing the production line to be unable to produce normally. After increasing the automatic adjustment function of the motor load, the temperature of each tension roller motor reaches dynamic relative balance, which greatly reduces the influence of the temperature imbalance of each tension roller motor on the production line during long-time and high-strength production process, improves the stability of the cold rolling mill production line, and provides strong guarantee for the production of high-strength products. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is the system connection block diagram of the present application;

[0025] Figure 2 It is the method flow chart of the present application;

[0026] Figure 3 It is the side view of the tension roller motor;

[0027] Figure 4 It is the temperature and load curve of 2# tension roller before using the present application;

[0028] Figure 5 It is the temperature and load curve of 2# tension roller after using the present application;

[0029] Figure 6 It is the temperature and load curve of 4# tension roller before using the present application;

[0030] Figure 7 It is the temperature and load curve of 4# tension roller after using the present application;

[0031] Figure 8 The internal module connection diagram of the PLC control module.

[0032] Wherein, 1, front bearing of tension roller motor, 2, first part of stator of tension roller motor, 3, second part of stator of tension roller motor, 4, third part of stator of tension roller motor, 5, rear bearing of tension roller motor, 6, temperature of No.1 motor before using the application for 2# tension roller, 7, temperature of No.2 motor before using the application for 2# tension roller, 8, temperature of No.3 motor before using the application for 2# tension roller, 9, actual torque of No.1 motor before using the application for 2# tension roller, 10, actual torque of No.2 motor before using the application for 2# tension roller, 11, actual torque of No.3 motor before using the application for 2# tension roller, 12, temperature of No.1 motor after using the application for 2# tension roller, 13, temperature of No.2 motor after using the application for 2# tension roller, 14, temperature of No.3 motor after using the application for 2# tension roller, 15, actual torque of No.1 motor after using the application for 2# tension roller, 16, actual torque of No.2 motor after using the application for 2# tension roller, 17, actual torque of No.3 motor after using the application for 2# tension roller, 18, temperature of No.4 motor before using the application for 4# tension roller, 19, temperature of No.5 motor before using the application for 4# tension roller, 20, actual torque of No.4 motor before using the application for 4# tension roller, 21, actual torque of No.5 motor before using the application for 4# tension roller, 22, temperature of No.4 motor after using the application for 4# tension roller, 23, temperature of No.5 motor after using the application for 4# tension roller, 24, actual torque of No.4 motor after using the application for 4# tension roller, 25, actual torque of No.5 motor after using the application for 4# tension roller. DETAILED DESCRIPTION

[0033] The application will be further described below in conjunction with the drawings.

[0034] Please refer to Figure 1 The application provides an embodiment: a system for adjusting tension roller motor load according to temperature, characterized in that: comprising a frequency converter, a tension roller motor, a PLC control module and a temperature measuring element;

[0035] The temperature measuring element is installed on the tension roller motor and connected to the PLC control module, and is used for collecting tension roller motor temperature;

[0036] The control unit of the frequency converter is connected to the PLC control module through a network, and is used for receiving control words sent by the PLC control module and driving the three-phase asynchronous motor;

[0037] The tension roller motor is connected to the output end of the frequency converter, and is used for executing speed and torque instructions sent by the frequency converter;

[0038] The PI controller load coefficient of the tension roller motor accesses the control word of the PLC control module, and is used for feeding back to the frequency converter through temperature calculation and load coefficient calculation of the PLC control module.

[0039] The system is composed of a Siemens S120 frequency converter, a three-phase asynchronous motor, a Siemens PLC control module and a temperature measuring element PT100. The temperature measuring element accesses the RTD module of the PLC control module for motor temperature acquisition. The control unit CU320 of the frequency converter communicates with the PLC control module through a Profinet network, receives the control word sent by the PLC and drives the motor. The motor accesses the output end of the frequency converter for executing the speed and torque instructions sent by the frequency converter, and the load coefficient of each motor is calculated in real time through control calculation and sent to the frequency converter.

[0040] Please continue to refer to Figure 3 As shown in the drawings, in an embodiment of the present application, the front bearing of the tension roller motor is provided with one temperature measuring element, different parts of the stator of the tension roller motor are provided with three temperature measuring elements, and the rear bearing of the tension roller motor is provided with one temperature measuring element. Five temperature measuring elements PT100 are installed on each tension roller motor, one (such as Figure 3 No. 1 in the drawings) in the front bearing, one (such as Figure 3 No. 2 in the drawings) in the front end of the stator, one (such as Figure 3 No. 3 in the drawings) in the middle of the stator, one (such as Figure 3 No. 4 in the drawings) in the rear end of the stator, and one (such as Figure 3 No. 5 in the drawings) in the rear bearing, which are connected to the RTD module of the PLC system for temperature acquisition

[0041] Please continue to refer to Figure 8As shown, in an embodiment of the present application, the PLC control module comprises an RTD module, a setting variable module, a temperature calculation module and a load coefficient calculation module, the RTD module is used for interfacing with the temperature measuring element to receive temperature data, the setting variable module is used for setting input, output and intermediate variables, the input variables include whether the load automatic adjustment function is put into use (manually set according to actual conditions), the number of tension roller motors (manually set according to actual conditions), the motor temperature detection value (the feedback value of the temperature measuring element input into the RTD module, used for calculating the load coefficient), the load coefficient limit (manually set according to actual conditions), the output variables include the load coefficient of each three-phase asynchronous motor (calculated by the load coefficient calculation module), and the intermediate variables include the calculation temperature intermediate process quantity (calculated by the temperature calculation module); the temperature data received by the RTD module is filled into the motor temperature detection value in the setting variable module, the motor temperature detection value in the setting variable module and the number of tension roller motors are calculated by the temperature calculation module to obtain the calculation temperature intermediate process quantity, and the calculation temperature intermediate process quantity is calculated by the load coefficient calculation module to obtain the load coefficient of the tension roller motor. By setting the load coefficient limit, when the calculation coefficient exceeds the corresponding limit, the output is performed according to the limit to prevent the phenomenon of overshoot; the temperature setting value at which the automatic adjustment load coefficient function starts to work is set (manually set according to actual conditions), that is, when the calculation temperature of any one motor reaches the set temperature, the function starts to work.

[0042] In an embodiment of the present application, the tension roller motor is a three-phase asynchronous motor.

[0043] Please continue to refer to Figure 2 As shown, the implementation method capable of better facilitating the operation of the system for adjusting the load of the tension roller motor according to the temperature comprises the following steps:

[0044] Step S1, the temperature measuring element collects the temperature of the tension roller motor and uploads it to the PLC control module;

[0045] Step S2, the PLC control module performs temperature calculation on the temperature data collected by the temperature measuring element to obtain the load coefficient and feedback to the frequency converter;

[0046] Step S3, the frequency converter executes the speed and torque instructions issued according to the load coefficient to the tension roller motor.

[0047] The temperature calculation in the step S2 is specifically that the calculation temperature of each tension roller motor is obtained by weighted average according to the feedback value of the temperature measuring element;

[0048] The calculation temperature formula is: t = [(T1+T2+T3+……+Tn) / n]*50%+T1*30%+T2*30%+T3*30%+……+Tn*30% (n is the number of tension roller motors, T1, T2, T3, …, Tn are the feedback values of the temperature measuring elements of the tension roller motors, and t is the calculation temperature of each tension roller motor). n n+1 *30%+T​n+2 20%;

[0049] Wherein, t represents the temperature of the tension roller motor, n represents the number of temperature measuring elements distributed on the stator of the tension roller motor; T n represents the temperature collected by the temperature measuring element at the nth position of the stator of the tension roller motor; T n+1 represents the temperature collected by the temperature measuring element at the front bearing of the tension roller motor; T n+2 represents the temperature collected by the temperature measuring element at the front bearing of the tension roller motor.

[0050] The temperature of each motor is obtained by weighted average of the feedback values of the five temperature measuring points, the three stator temperatures are T1, T2 and T3, the front bearing temperature is T4, and the rear bearing temperature is T5, and the calculation temperature t = [(T1+T2+T3) / 3]*50%+T4*30%+T5*20%.

[0051] The load coefficient in the step S2 is specifically adjusted by the proportion of the calculation temperature deviation between each tension roller motor;

[0052] The load coefficient calculation formula is: C n =1+1 / n-t n / (t1+t2+……+t n );

[0053] Wherein, C n represents the load coefficient of the nth tension roller motor; n represents n tension roller motors; t n represents the temperature of the nth tension roller motor.

[0054] According to the actual number of tension roller motors, it is divided into three cases: two motors, three motors and four motors, and according to the specific situation, the load coefficient is adjusted by the proportion of the calculation temperature deviation between each motor.

[0055] When the number of motors is two, the calculation temperatures are t1 and t 2, The load coefficients are C1 and C2

[0056] C1=1+1 / 2-t1 / (t 1+ t2)

[0057] C2=1+1 / 2-t2 / (t 1+ t2)

[0058] When the number of motors is three, the calculation temperatures are t1, t2 and t3, and the load coefficients are C1, C2 and C3

[0059] C1=1+1 / 3-t1 / (t1+t2+t3)

[0060] C2 = 1 + 1 / 3 - t2 / (t1 + t2 + t3)

[0061] C3 = 1 + 1 / 3 - t3 / (t1 + t2 + t3)

[0062] When the number of motors is 4, the calculated temperatures are t1, t2, t3, t4, and the load coefficients are C1, C2, C3, C4, respectively

[0063] C1 = 1 + 1 / 4 - t1 / (t1 + t2 + t3 + t4)

[0064] C2 = 1 + 1 / 4 - t2 / (t1 + t2 + t3 + t4)

[0065] C3 = 1 + 1 / 4 - t3 / (t1 + t2 + t3 + t4)

[0066] C4 = 1 + 1 / 4 - t4 / (t1 + t2 + t3 + t4)

[0067] The application will be further described below in conjunction with specific embodiments,

[0068] Embodiment 1

[0069] Please refer to Figure 4 and Figure 5 shown, the front 2# tension roller of the descaling machine, the number of rollers and motors is 3, before using the improved patent, the motor temperature of the 2# roller is close to 75℃, close to the alarm setting temperature 80℃, and the motor temperature of the 1# roller is less than 65℃ (as shown in Figure 4 ). After adjusting the load according to the temperature, the temperatures of the 3 motors tend to be balanced, and are basically maintained below 70℃ (as shown in Figure 5 ).

[0070] Embodiment 2

[0071] Please refer to Figure 6 and Figure 7 shown, the front 4# tension roller of the temper mill, the number of rollers and motors is 2, before using the improved patent, the motor temperature of the 1# roller is close to 100℃, which has exceeded the alarm setting temperature 80℃, close to the failure temperature 110℃, and the motor temperature of the 2# roller is about 85℃ (as shown in Figure 6 ). After adjusting the load according to the temperature, the temperatures of the 2 motors tend to be balanced, and are basically maintained at about 85℃ (as shown in Figure 7 ).

[0072] The above only describes the preferred embodiments of the application, and should not be understood as limiting the application. Any changes and modifications made within the scope of the application should be included in the scope of the application.

Claims

1. A method of implementing a system for regulating the load of a tension roll motor as a function of temperature, characterized in that: The system comprises a frequency converter, a tension roller motor, a PLC control module and a temperature measuring element; The temperature measuring element is installed on the tension roller motor and connected to the PLC control module for collecting the temperature of the tension roller motor; The control unit of the frequency converter is connected to the PLC control module through a network for receiving the control word sent by the PLC control module and driving the tension roller motor; The tension roller motor is connected to the output end of the frequency converter for executing the speed and torque instructions sent by the frequency converter; The PI controller of the tension roller motor is connected to the control word of the PLC control module for feeding back the load coefficient calculated by the PLC control module through temperature calculation to the frequency converter; The implementation method comprises the following steps: Step S1, the temperature measuring element collects the temperature of the tension roller motor and uploads it to the PLC control module; Step S2, the PLC control module calculates the load coefficient through the temperature data collected by the temperature measuring element and feeds it back to the frequency converter; Step S3, the frequency converter executes the speed and torque instructions sent according to the load coefficient to the tension roller motor; In step S2, the load coefficient is calculated by adjusting the load coefficient according to the proportional deviation of the calculated temperature between each tension roller motor; The load coefficient calculation formula is: C k = 1 + 1 / k-t k / (t1+t2+……+t k ); wherein C k represents the load coefficient of the kth tension roller motor; k represents that there are k tension roller motors; t k represents the temperature of the kth tension roller motor.

2. The method of claim 1, wherein the method further comprises: determining a temperature of the motor; and adjusting the load on the motor based on the temperature of the motor. In step S2, the temperature calculation is a weighted average calculation of the temperature of each tension roller motor according to the feedback value of the temperature measuring element; The temperature formula is: t = [(T1+T2+T3+…+T n ) / n]*50%+T n+1 *30%+T n+2 *20%; Wherein, t represents the temperature of the tension roller motor, n represents the number of temperature measuring elements distributed on the stator of the tension roller motor; T n represents the temperature collected by the temperature measuring element at the nth position of the stator of the tension roller motor; n+1 represents the temperature collected by the temperature measuring element at the front bearing of the tension roller motor; n+2 represents the temperature collected by the temperature measuring element at the rear bearing of the tension roller motor.

3. The method of claim 1, wherein the method further comprises: determining a temperature of the motor; and adjusting the motor load based on the determined temperature. One temperature measuring element is installed on the front bearing of the tension roller motor, three temperature measuring elements are installed on different parts of the stator of the tension roller motor, and one temperature measuring element is installed on the rear bearing of the tension roller motor.

4. The method of claim 1, wherein the method further comprises: determining a temperature of the motor; and adjusting the motor load based on the temperature of the motor. The PLC control module comprises an RTD module, a setting variable module, a temperature calculation module and a load coefficient calculation module, the RTD module is used to interface with the temperature measuring element and receive temperature data, the setting variable module is used to set input, output and intermediate variables, the input variables include whether the load automatic adjustment function is put into use, the number of tension roller motors, motor temperature detection values and load coefficient limits, the output variables include the load coefficient of each three-phase asynchronous motor, and the intermediate variables include the intermediate process quantity of the calculated temperature; The temperature data received by the RTD module is filled into the motor temperature detection value in the setting variable module, the motor temperature detection value in the setting variable module and the number of tension roller motors are calculated through the temperature calculation module to obtain the intermediate process quantity of the calculated temperature, and the intermediate process quantity of the calculated temperature is calculated through the load coefficient calculation module to obtain the load coefficient of the tension roller motor.

5. The method of claim 1, wherein the method further comprises: determining a temperature of the motor; and adjusting the load on the motor based on the temperature of the motor. The tension roller motor is a three-phase asynchronous motor.

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