Frequency converter of drilling winch and control method thereof
By automatically taking effect in the inverter of the drilling rig winch, the frequency setting value is adjusted based on the output torque and frequency target value, the problem of the inverter outputting a large torque for a long time during zero-speed operation is solved, and the risk of failure and wear of the brake holding device is reduced.
Patent Information
- Application Number
- CN202411917170.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-20
- Publication Date
- 2025-04-25
AI Technical Summary
During the zero-speed operation of the drilling rig winch, the state of the brake holding device is not sent to the inverter, causing the inverter to output a large torque for a long time, which may cause a fault or increase the wear of the brake holding device.
When the inverter's unloading state takes effect, the frequency setting value is determined based on the output torque and the frequency target value, and superimpose it with the zero-speed position control output value to obtain the speed loop input reference value, thereby driving the motor and reducing the torque amplitude value output by the inverter.
It effectively avoids faults caused by the long-term output of large torque during zero-speed operation, and reduces wear of the brake holding device.
Smart Images
Figure CN119891869A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of frequency converters, and in particular to a frequency converter for a drilling rig winch and a control method thereof. Background Art
[0002] In the field of oil drilling rigs, the winch is an important equipment of the lifting system and the core equipment of the drilling rig. The winch is equipped with a brake device, i.e. a disc brake or a safety clamp, and the control logic of the brake device is generally implemented by a PLC (Programmable Logic Controller).
[0003] When making or breaking the hook, the winch is in a zero-speed hovering state and the brake is not engaged. The inverter needs to have a zero-speed position control function to achieve zero-speed hovering. If the state of the brake device is not sent to the inverter, the inverter may continue to operate after the brake is engaged. After the brake device is put into operation, the motor cannot rotate, but the position reference value recorded by the zero-speed position control module may not be the current position. The zero-speed position control module outputs a value, that is, the speed loop reference value is not zero, and the speed feedback value is zero, resulting in a continuous increase in torque, which may further cause the inverter to report a fault, such as a stall or overload fault, increasing the wear of the brake device.
[0004] For some lifting brake applications that do not require zero-speed suspension, the brake device status is not sent to the inverter. If the upper controller issues a brake command when the inverter is running at zero speed, the speed loop set value is zero, the speed feedback value is zero, and the speed loop integrator remains unchanged, that is, the output torque remains unchanged, which may also cause the inverter overload fault and increase the wear of the brake device.
[0005] Therefore, the inverter needs a force unloading method to avoid the inverter outputting a large torque for a long time during zero-speed operation when the brake device is locked and the status is not sent to the inverter, causing failure or increasing wear of the brake device. Summary of the invention
[0006] In view of this, the purpose of the present application is to provide a frequency converter for a drilling rig winch and a control method thereof, so as to avoid the problem that when the brake device is engaged and the status is not sent to the frequency converter, the frequency converter outputs a large torque for a long time during zero-speed operation, causing failure or increased wear of the brake device.
[0007] The technical solutions adopted by this application to solve the above technical problems are as follows:
[0008] In a first aspect, the present application provides a frequency converter control method for a drilling rig winch, wherein the drilling rig winch further includes a motor and a brake device; the control method includes:
[0009] When the inverter unloading state is effective, the frequency setting value is determined based on the inverter output torque and the frequency target value;
[0010] The frequency setting value is superimposed on the zero-speed position control output value to obtain a speed loop input reference value;
[0011] Based on the speed loop input reference value and the speed loop input feedback value, a speed loop output value is obtained to drive the motor.
[0012] A second aspect of the present application provides a frequency converter for a drilling rig winch, the frequency converter for the drilling rig winch comprising a control unit, the control unit comprising a memory and a processor, the memory being configured to store a computer program, and the processor implementing the frequency converter control method for the drilling rig winch described in the first aspect when executing the computer program.
[0013] The inverter of the drilling rig winch and the control method thereof provided in the embodiment of the present application include the inverter output torque in the frequency setting value calculation when the unloading state of the inverter takes effect, thereby achieving a reduction in the output torque amplitude during the zero-speed operation and braking of the inverter, avoiding inverter overload failure and reducing wear on the braking device. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 A schematic diagram of a frequency converter control method for a drilling rig winch provided in an embodiment of the present application;
[0015] Figure 2 Schematic diagram of zero-speed position control, force unloading control and speed loop control provided in an embodiment of the present application.
[0016] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION
[0017] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application clearer and more understandable, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.
[0018] like Figure 1 As shown, the embodiment of the present application provides a frequency converter control method for a drilling rig winch, wherein the drilling rig winch also includes a motor, a brake device, and an encoder; the frequency converter control method for the drilling rig winch includes the steps of:
[0019] S11, when the inverter unloading state is effective, determining the frequency setting value based on the inverter output torque and the frequency target value;
[0020] S12, the frequency setting value is superimposed on the zero-speed position control output value to obtain a speed loop input reference value;
[0021] S13. Obtaining a speed loop output value based on the speed loop input reference value and the speed loop input feedback value to drive the motor.
[0022] In one example, before the unloading state of the frequency converter takes effect, the control method further includes:
[0023] When the inverter enables the zero-speed position control function and the frequency setting value is zero, the inverter's zero-speed position control function takes effect;
[0024] When the zero-speed position control function of the frequency converter is effective, the output torque of the frequency converter and the position change detected by the encoder are obtained;
[0025] If the inverter output torque is higher than the first torque threshold and the duration of the position change detected by the encoder being lower than the first position change threshold reaches a first time threshold, the inverter unloading state takes effect.
[0026] In the specific implementation, when the inverter zero speed position control function is effective, if the inverter output torque T out The absolute value of the torque is higher than the first torque threshold T lim_1 And the position change P detected by the encoder Δ Below the first position change threshold P lim_1 The duration of the time reaches the first time threshold t m_1 , the inverter's force-unloading state takes effect, that is, it enters the force-unloading state.
[0027] In one example, if the unloading state is effective for the first time, the position reference value of the zero-speed position control is updated to the current rotor position. It should be noted that if the inverter does not enable the zero-speed hovering function, the position reference value of the zero-speed position control does not need to be updated when entering the unloading state for the first time.
[0028] The first unloading state takes effect when the inverter enters the unloading state from the non-unloading state for the first time after the inverter runs at zero speed.
[0029] In one example, when the zero-speed position control function of the frequency converter takes effect, before the frequency setting value is superimposed on the zero-speed position control output value to obtain the speed loop input reference value, the control method further includes:
[0030] The position reference value of the zero-speed position control and the real-time rotor position detected by the encoder are passed through a zero-speed position controller to obtain the zero-speed position control output value.
[0031] In one example, before the unloading state of the frequency converter takes effect, the control method further includes:
[0032] When the inverter is running at zero speed and the zero-speed position control function is not enabled, the zero-speed position control output value is cleared;
[0033] That is to say, the zero-speed position control function does not participate in the control process.
[0034] Obtain the frequency value after ramp processing, the inverter output torque, and the position change detected by the encoder;
[0035] If the frequency value after the ramp processing is zero, the inverter output torque is higher than the first torque threshold, and the duration of the position change detected by the encoder being lower than the first position change threshold reaches a first duration, the inverter unloading state takes effect.
[0036] In the specific implementation, the inverter does not enable the zero-speed position control function. During the inverter zero-speed operation, if the frequency value f after ramp processing AfRamp is zero, the inverter output torque T out The absolute value of the torque is higher than the first torque threshold T lim_1 And the position change P detected by the encoder Δ Below the first position change threshold P lim_1 The duration of the time reaches the first time threshold t m_1 , the inverter's force-unloading state takes effect, that is, it enters the force-unloading state.
[0037] In one example, determining the frequency setting value based on the inverter output torque and the frequency target value includes:
[0038] The inverter output torque is passed through the unloading controller to obtain an unloading control value;
[0039] The frequency target value is subjected to frequency ramp processing to obtain a frequency value after ramp processing;
[0040] The frequency setting value is determined according to the unloading control value and the frequency value after the ramp processing.
[0041] Wherein, after the inverter output torque passes through the unloading controller, the unloading control value is obtained, including:
[0042] The inverter output torque is low-pass filtered and then multiplied by the unloading control proportional coefficient to obtain the unloading control value.
[0043] In the specific implementation, Figure 2 As shown, the frequency target value f tgt After frequency ramp processing, the frequency value f after ramp processing is obtained AfRamp When the unloading state takes effect, the inverter outputs torque T out After low-pass filtering (LPF in the figure), it is multiplied by the unloading force control proportional coefficient to obtain the unloading force control value. The unloading force control value is proportional to the frequency value f after ramp processing.AfRamp Subtract and get the frequency setting value f ref That is, the unloading control value and the frequency value f after ramp processing AfRamp Together with the frequency setting value f ref The general droop function block diagram of the inverter is similar to this, and this function effect can also be achieved. Taking the inverter output positive torque as an example, when the unloading state is effective, the unloading control output is negative, and the speed loop input reference value tends to decrease, which reduces the inverter output torque.
[0044] In the specific implementation, Figure 2 As shown, the zero-speed position controller can be a proportional coefficient controller or other forms. Generally, when the zero-speed position control function takes effect, the rotor position detected by the encoder is recorded at the start of the function, and the rotor position is used as the position reference value of the zero-speed position control function. The zero-speed position control function is invalid, and the zero-speed control output is cleared.
[0045] In one example, the control method further includes:
[0046] While the inverter's unloading state is in effect, the position change detected by the encoder is obtained;
[0047] If the position change detected by the encoder is higher than a second position change threshold, the unloading state is exited and the unloading state is not entered again during the second duration.
[0048] In a specific implementation, if the position change P detected by the encoder is Δ Higher than the second position change threshold P lim_2 , it is considered that the external brake is not engaged, and the force-unloading state is exited and the second duration t m_2 During this period, the system will no longer enter the force unloading state.
[0049] In one example, the control method further includes:
[0050] During the period when the unloading state of the frequency converter is effective, if the frequency value after ramp processing is not zero or the frequency target value is not zero or the output torque of the frequency converter is lower than the second torque threshold, the unloading state is exited.
[0051] In a specific implementation, if the inverter outputs torque T out The absolute value of is lower than the second torque threshold T lim_2 , then exit the unloading state and complete the unloading process. If the frequency value f after ramp processing AfRamp Not zero or frequency target value f tgt If it is not zero, the unloading state is exited and the inverter responds to the user's frequency setting to accelerate or decelerate.
[0052] In the specific implementation, Figure 2As shown, the speed loop input reference value and the speed loop input feedback value are subtracted and passed through a speed loop controller to obtain a speed loop output value to drive the motor. A typical speed loop controller may be a proportional integral controller.
[0053] Another embodiment of the present application provides a frequency converter for a drilling rig winch, wherein the frequency converter for the drilling rig winch includes a control unit, wherein the control unit includes a memory and a processor, wherein the memory is configured to store a computer program, and when the processor executes the computer program, the frequency converter control method for the drilling rig winch described in the aforementioned embodiment is implemented.
[0054] It should be noted that in the above description, “higher than” may mean greater than or equal to, or only greater than; and “lower than” may mean less than or equal to, or only less than.
[0055] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.
[0056] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.
[0057] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
[0058] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.
[0059] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a disk or an optical disk.
[0060] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.
Claims
1. A frequency converter control method for a drilling rig winch, wherein the drilling rig winch comprises a motor and a brake device; characterized in that: The control method comprises: When the inverter unloading state is effective, the frequency setting value is determined based on the inverter output torque and the frequency target value; The frequency setting value is superimposed on the zero-speed position control output value to obtain a speed loop input reference value; Based on the speed loop input reference value and the speed loop input feedback value, a speed loop output value is obtained to drive the motor.
2. The control method according to claim 1, characterized in that: The drilling rig winch also includes an encoder; before the unloading state of the frequency converter takes effect, the control method also includes: When the inverter enables the zero-speed position control function and the frequency setting value is zero, the inverter's zero-speed position control function takes effect; When the zero-speed position control function of the frequency converter is effective, the output torque of the frequency converter and the position change detected by the encoder are obtained; If the inverter output torque is higher than the first torque threshold and the duration of the position change detected by the encoder being lower than the first position change threshold reaches a first time threshold, the inverter unloading state takes effect.
3. The control method according to claim 2, characterized in that: The control method further comprises: If the first unloading state takes effect, the position reference value of the zero-speed position control is updated to the current rotor position.
4. The control method according to claim 1, characterized in that: The drilling rig winch also includes an encoder; when the zero-speed position control function of the frequency converter takes effect, before the frequency setting value is superimposed on the zero-speed position control output value to obtain the speed loop input reference value, the control method also includes: The position reference value of the zero-speed position control and the real-time rotor position detected by the encoder are passed through a zero-speed position controller to obtain the zero-speed position control output value.
5. The control method according to claim 1, characterized in that: Before the unloading state of the frequency converter takes effect, the control method further includes: When the inverter is running at zero speed and the zero-speed position control function is not enabled, the zero-speed position control output value is cleared; Obtain the frequency value after ramp processing, the inverter output torque, and the position change detected by the encoder; If the frequency value after the ramp processing is zero, the inverter output torque is higher than the first torque threshold, and the duration of the position change detected by the encoder being lower than the first position change threshold reaches a first duration, the inverter unloading state takes effect.
6. The control method according to claim 1, characterized in that: The step of determining the frequency setting value based on the inverter output torque and the frequency target value includes: The inverter output torque is passed through the unloading controller to obtain an unloading control value; The frequency target value is subjected to frequency ramp processing to obtain a frequency value after ramp processing; The frequency setting value is determined according to the unloading control value and the frequency value after the ramp processing.
7. The control method according to claim 6, characterized in that: After the inverter output torque passes through the unloading controller, the unloading control value is obtained, including: The inverter output torque is low-pass filtered and then multiplied by the unloading control proportional coefficient to obtain the unloading control value.
8. The control method according to claim 1, characterized in that: The control method further comprises: While the inverter's unloading state is in effect, the position change detected by the encoder is obtained; If the position change detected by the encoder is higher than a second position change threshold, the unloading state is exited and the unloading state is not entered again during the second duration.
9. The control method according to claim 1, characterized in that: The control method further comprises: During the period when the unloading state of the frequency converter is effective, if the frequency value after ramp processing is not zero or the frequency target value is not zero or the output torque of the frequency converter is lower than the second torque threshold, the unloading state is exited.
10. A frequency converter for a drilling rig winch, characterized in that: The frequency converter of the drilling rig winch includes a control unit, the control unit includes a memory and a processor, the memory is configured to store a computer program, and the processor implements the frequency converter control method of the drilling rig winch as described in any one of claims 1-9 when executing the computer program.