Method for protecting tower crane controller and frequency converter in cooperation, control device and protection system

Abstract

The application relates to the field of engineering machinery and discloses a tower crane controller and frequency converter cooperative protection method, a control device and a protection system. The tower crane controller and frequency converter cooperative protection method comprises the following steps: receiving a tower crane protection starting signal; and in response to the tower crane protection starting signal, selecting a tower crane protection mode of tower crane controller control, frequency converter control or tower crane controller and frequency converter joint control. The tower crane controller and frequency converter cooperative protection method can improve the diversity of the tower crane protection mode, effectively avoid the failure of the motor side sensor, and cause the protection function to fail or false alarm, thereby improving the reliability of the tower crane protection.

Description

Technical Field

[0001] This invention belongs to the field of engineering machinery, specifically relating to a method, control device and protection system for the coordinated protection of tower crane controller and frequency converter. Background Technology

[0002] Tower cranes are widely used material handling machinery on construction sites. They typically use frequency converters to control the operation of motors in various mechanisms, thereby achieving operations such as hoisting, slewing, and luffing. To ensure the reliable and safe operation of tower cranes, multiple protection functions are usually installed. However, in existing tower cranes, sensors are generally installed on each motor to detect the operating status of each motor and feed the data back to the corresponding frequency converter. The frequency converter then controls the motor according to the set protection strategy based on the feedback information to achieve the corresponding protection function. This method of protection through sensors on the motor and frequency converter is relatively simple. If the sensors on the motor malfunction, the protection function will fail or false alarms will occur, resulting in low reliability. Summary of the Invention

[0003] In view of the above-mentioned shortcomings or defects in the prior art, the present invention provides a method, control device and protection system for coordinated protection of tower crane controller and frequency converter, aiming to solve the technical problems of the relatively simple and unreliable existing tower crane protection methods.

[0004] To achieve the above objectives, the present invention provides a method for coordinated protection of a tower crane controller and a frequency converter, the method comprising:

[0005] Receive tower crane protection start signal;

[0006] In response to the tower crane protection start signal, the tower crane can be protected by means of tower crane controller control, frequency converter control, or joint control by tower crane controller and frequency converter.

[0007] Optionally, the step of selecting tower crane protection mode control, frequency converter control, or joint control by tower crane controller and frequency converter in response to the tower crane protection start signal includes:

[0008] In response to the tower crane protection start signal, the status of the tower crane controller-side sensors and the motor-side sensors is acquired, and based on the status of the tower crane controller-side sensors and the motor-side sensors, the tower crane is protected by a combination of tower crane controller control, frequency converter control, or joint control by the tower crane controller and frequency converter.

[0009] Optionally, the step of selecting between tower crane controller control, frequency converter control, or a combination of tower crane controller and frequency converter control to protect the tower crane based on the states of the tower crane controller-side sensors and the motor-side sensors includes:

[0010] The status of the tower crane controller-side sensor and the motor-side sensor are determined separately. If the tower crane controller-side sensor is in normal working condition and the motor-side sensor is in fault condition, the tower crane controller controls and protects the tower crane based on the tower crane controller-side sensor. If the tower crane controller-side sensor is in fault condition and the motor-side sensor is in normal working condition, the frequency converter controls and protects the tower crane based on the motor-side sensor. If both the tower crane controller-side sensor and the motor-side sensor are in normal working condition, a priority strategy is determined to prioritize controlling and protecting the tower crane through the tower crane controller, or prioritize controlling and protecting the tower crane through the frequency converter, or jointly control and protect the tower crane through both the tower crane controller and the frequency converter.

[0011] Optionally, the priority strategy is set by comparing the detection reliability of the tower crane controller-side sensors and the motor-side sensors.

[0012] Optionally, the tower crane protection start signals include a variable load stop protection signal, a load-following speed protection signal, a brake failure protection signal, and a luffing anti-sway protection signal.

[0013] The present invention also provides a control device, the control device comprising:

[0014] The receiving unit is used to receive tower crane protection start signals;

[0015] The control unit is configured as follows:

[0016] In response to the tower crane protection start signal, the tower crane can be protected by means of tower crane controller control, frequency converter control, or joint control by tower crane controller and frequency converter.

[0017] Optionally, the control unit is further configured to:

[0018] In response to the tower crane protection start signal, the status of the tower crane controller-side sensors and the motor-side sensors is acquired, and based on the status of the tower crane controller-side sensors and the motor-side sensors, the tower crane is protected by a combination of tower crane controller control, frequency converter control, or joint control by the tower crane controller and frequency converter.

[0019] Optionally, the processing unit is further configured to:

[0020] The status of the tower crane controller-side sensor and the motor-side sensor are determined separately. If the tower crane controller-side sensor is in normal working condition and the motor-side sensor is in fault condition, the tower crane controller controls and protects the tower crane based on the tower crane controller-side sensor. If the tower crane controller-side sensor is in fault condition and the motor-side sensor is in normal working condition, the frequency converter controls and protects the tower crane based on the motor-side sensor. If both the tower crane controller-side sensor and the motor-side sensor are in normal working condition, the tower crane is first controlled and protected by the tower crane controller according to the set priority strategy, or the tower crane is first controlled and protected by the frequency converter, or the tower crane controller and the frequency converter jointly control and protect the tower crane.

[0021] Optionally, the priority strategy is set by comparing the detection reliability of the tower crane controller-side sensors and the motor-side sensors.

[0022] The present invention also provides a tower crane protection system, which includes a tower crane controller-side sensor, a motor-side sensor, and the aforementioned control device, wherein the control device is communicatively connected to the tower crane controller-side sensor and the motor-side sensor, respectively.

[0023] The tower crane controller and frequency converter coordinated protection method of the present invention includes two protection modes: tower crane controller control protection and frequency converter control protection. After receiving the tower crane protection start signal, the tower crane can be protected by tower crane controller control, frequency converter control, or joint control by tower crane controller and frequency converter. This setting improves the diversity of tower crane protection modes, effectively avoids the situation where the protection function fails or false alarms occur due to the failure of motor side sensors, and improves the reliability of tower crane protection.

[0024] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0025] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0026] Figure 1 This is a flowchart illustrating a method for coordinated protection of tower crane controller and frequency converter in one embodiment of the present invention. Detailed Implementation

[0027] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other.

[0029] In this invention, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used to describe the relative positions of components in relation to the directions shown in the accompanying drawings or in relation to the vertical, perpendicular, or gravitational directions.

[0030] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0031] This invention first provides a method for coordinated protection of tower crane controller and frequency converter.

[0032] In one implementation, refer to the appendix. Figure 1 As shown, the collaborative protection method between the tower crane controller and the frequency converter includes:

[0033] Receive tower crane protection start signal;

[0034] In response to the tower crane protection start signal, the tower crane can be protected by selecting the tower crane controller control, frequency converter control, or a combination of tower crane controller and frequency converter control.

[0035] In this embodiment, the tower crane controller and frequency converter collaborative protection method includes two protection modes: tower crane controller control protection and frequency converter control protection. After receiving the tower crane protection start signal, the tower crane can be protected by tower crane controller control, frequency converter control, or joint control by the tower crane controller and frequency converter. Compared with the existing tower crane protection method that only uses the frequency converter for protection, this setting improves the diversity of tower crane protection methods, effectively avoids the situation where the protection function fails or false alarms occur due to the failure of the motor side sensor, and improves the reliability of tower crane protection.

[0036] In one implementation, the step of protecting the tower crane in response to a tower crane protection activation signal, selecting a method of tower crane controller control, inverter control, or joint control by the tower crane controller and inverter, includes:

[0037] In response to the tower crane protection start signal, the system acquires the status of the sensors on the tower crane controller side and the motor side, and selects the tower crane protection mode based on the status of the sensors on the tower crane controller side and the motor side, namely, tower crane controller control, frequency converter control, or joint control by the tower crane controller and frequency converter.

[0038] It should be noted that the tower crane controller-side sensor is a sensor installed on the tower crane mechanism to detect the operation of the mechanism and communicate with the tower crane controller. For details, please refer to the following implementation method. The motor-side sensor is a sensor installed on the motor of the mechanism to detect the operation of the motor and communicate with the corresponding frequency converter.

[0039] Further, refer to the appendix Figure 1 As shown, the steps for protecting the tower crane by selecting between tower crane controller control, frequency converter control, or a combination of both, based on the status of the sensors on the tower crane controller side and the motor side, include:

[0040] The status of the tower crane controller-side sensors and the motor-side sensors are determined separately. If the tower crane controller-side sensor is in normal working condition and the motor-side sensor is in fault condition, the tower crane is protected by the tower crane controller based on the tower crane controller-side sensor status. If the tower crane controller-side sensor is in fault condition and the motor-side sensor is in normal working condition, the tower crane is protected by the frequency converter based on the motor-side sensor status. If both the tower crane controller-side sensor and the motor-side sensor are in normal working condition, the tower crane is protected by the tower crane controller first, or by the frequency converter first, or by both the tower crane controller and the frequency converter.

[0041] In this embodiment, two protection modes are provided: tower crane controller control protection and frequency converter control protection. The system first determines the status of the sensors on the tower crane controller side and the motor side, and then selects tower crane controller control protection and / or frequency converter control protection based on the determination result and a set priority strategy. This configuration increases the diversity of tower crane protection modes and effectively avoids situations where a fault in the motor side sensor leads to protection failure or false alarms, thus improving the reliability of tower crane protection. Furthermore, when both the tower crane controller side and motor side sensors are in normal working condition, the system selects tower crane controller control protection and / or frequency converter control protection according to the set priority strategy. This prioritizes protection modes with less interference, fluctuation, and higher reliability, further improving the reliability and timeliness of tower crane protection.

[0042] In one implementation, the priority strategy can be preset by comparing the detection reliability of the tower crane controller-side sensors and the motor-side sensors.

[0043] In one implementation, the tower crane protection start signals include a variable load stop protection signal, a load-following speed protection signal, a brake failure protection signal, and a luffing anti-sway protection signal.

[0044] Understandably, load change-stop protection is a protection mechanism that quickly stops the tower crane when the weight of a load changes suddenly during lifting or suspending; load-following-speed protection is a protection mechanism that limits the lifting speed of the load based on the lifting weight during lifting; brake failure protection is a protection mechanism that uses the motor to apply force to the load to suspend it when the brake fails; and luffing anti-sway protection is a protection mechanism that limits the change in luffing speed of the load to reduce swaying during luffing.

[0045] Understandably, the tower crane controller and frequency converter collaborative protection method of this embodiment can be applied to tower crane variable load stop protection, load-following speed protection, brake failure protection and luffing anti-sway protection.

[0046] When applied to the variable load shutdown protection of tower cranes, the tower crane controller-side sensor is a weight sensor used to detect the lifting weight, the motor-side sensor is a torque sensor used to detect the output torque of the lifting motor, and the frequency converter is a lifting frequency converter that controls the lifting motor. Specifically, the tower crane controller controls the protection of the tower crane based on the sensor on its side: when the tower crane controller detects a sudden change in the lifting weight through the weight sensor, it controls the lifting motor to stop via the lifting frequency converter; similarly, the frequency converter controls the protection of the tower crane based on the sensor on its side: when the frequency converter detects a sudden change in the output torque of the lifting motor through the torque sensor, it controls the lifting motor to stop. In addition, since the hoisting frequency converter can only detect sudden changes in the weight of the hoisted object during the hoisting process through the torque sensor, and the detection results fluctuate greatly, it cannot detect sudden changes in the weight of the hoisted object during the hovering process because the torque sensor detects that the output torque of the hoisting motor is zero. However, the tower crane controller can detect sudden changes in the weight of the hoisted object during both the hoisting and hovering processes through the weight sensor. Therefore, the priority strategy is to prioritize controlling and protecting the tower crane through the tower crane controller.

[0047] When applied to load-and-speed protection for tower cranes, the tower crane controller-side sensor is a weight sensor for detecting the lifting weight, the motor-side sensor is a torque sensor for detecting the output torque of the hoisting motor, and the frequency converter is a hoisting inverter for controlling the hoisting motor. Specifically, the tower crane controller controls the protection of the tower crane based on the sensor on its side: the tower crane controller, based on the lifting weight detected by the weight sensor, controls the hoisting motor via the hoisting inverter to limit the lifting speed of the load; similarly, the frequency converter controls the protection of the tower crane based on the sensor on its side: the frequency converter, based on the output torque of the hoisting motor detected by the torque sensor, controls the hoisting motor to limit the lifting speed of the load. Furthermore, because the output torque of the hoisting motor detected by the hoisting inverter via the torque sensor cannot completely and accurately reflect the lifting weight during the lifting process, and the detection result fluctuates significantly during acceleration and deceleration, the priority strategy is to prioritize controlling and protecting the tower crane through the tower crane controller.

[0048] When applying brake failure protection to tower cranes, the tower crane controller-side sensor is a hoisting drum encoder used to detect the rotational angle position of the hoisting drum, and the motor-side sensor is a hoisting motor encoder used to detect the rotational angle position of the output shaft of the hoisting motor. The frequency converter is a hoisting inverter that controls the hoisting motor. Specifically, the tower crane controller controls the protection of the tower crane based on the controller-side sensors as follows: During hoisting and braking, when the tower crane controller detects a change in the rotational angle position of the hoisting drum through the hoisting drum encoder, it controls the hoisting motor to output lifting torque through the hoisting inverter to suspend the lifted load. Similarly, the frequency converter controls the protection of the tower crane based on the motor-side sensors as follows: During hoisting and braking, when the frequency converter detects a change in the rotational angle position of the output shaft of the hoisting motor through the hoisting motor encoder, it controls the hoisting motor to output lifting torque to suspend the lifted load. Furthermore, since the detection results of the hoisting drum encoder and the hoisting motor encoder are equivalent, meaning their detection reliability is equal, the priority strategy is to jointly control and protect the tower crane through the tower crane controller and the hoisting frequency converter.

[0049] When applied to the luffing anti-sway protection of tower cranes, the tower crane controller-side sensors are a hoisting drum encoder for detecting the rotational angle position of the hoisting drum and a luffing drum encoder for detecting the rotational speed of the luffing drum. The motor-side sensor is a luffing motor encoder for detecting the rotational speed of the output shaft of the luffing motor. The frequency converter is a luffing frequency converter for controlling the luffing motor. The tower crane controller controls and protects the tower crane based on sensors on its side as follows: During luffing, the tower crane controller uses the rotational angle position information of the hoisting drum detected by the hoisting drum encoder and the rotational speed information of the luffing drum detected by the luffing drum encoder. It then controls the luffing motor via a luffing inverter to limit changes in the luffing speed of the lifted load. Specifically, the tower crane controller calculates the height of the lifted load based on the rotational angle position information of the hoisting drum and the luffing speed based on the rotational speed information of the luffing drum. The height of the lifted load and the luffing speed are input into a set anti-sway model. The anti-sway model controls the speed change of the luffing motor, thereby controlling the change in the luffing speed. The tower crane is also protected via a frequency converter based on motor-side sensors. During luffing, the luffing inverter controls the luffing motor based on the rotational speed of the output shaft of the luffing motor detected by the luffing motor encoder to limit changes in the luffing speed of the lifted load. Furthermore, a priority strategy is set to prioritize controlling and protecting the tower crane via the luffing inverter.

[0050] The present invention also provides a control device, the control device comprising:

[0051] The receiving unit is used to receive tower crane protection start signals;

[0052] The control unit, which is communicatively connected to the receiving unit, is configured to:

[0053] In response to the tower crane protection start signal, the tower crane can be protected by selecting the tower crane controller control, frequency converter control, or a combination of tower crane controller and frequency converter control.

[0054] In one implementation, the control unit is further configured to:

[0055] In response to the tower crane protection start signal, the system acquires the status of the sensors on the tower crane controller side and the motor side, and selects the tower crane protection mode based on the status of the sensors on the tower crane controller side and the motor side, namely, tower crane controller control, frequency converter control, or joint control by the tower crane controller and frequency converter.

[0056] In one embodiment, the processing unit is further configured to:

[0057] The status of the tower crane controller-side sensors and the motor-side sensors are determined separately. If the tower crane controller-side sensor is in normal working condition and the motor-side sensor is in fault condition, the tower crane is protected by the tower crane controller based on the tower crane controller-side sensor status. If the tower crane controller-side sensor is in fault condition and the motor-side sensor is in normal working condition, the tower crane is protected by the frequency converter based on the motor-side sensor status. If both the tower crane controller-side sensor and the motor-side sensor are in normal working condition, the tower crane is protected by the tower crane controller first, or by the frequency converter first, or by both the tower crane controller and the frequency converter.

[0058] In one implementation, the priority strategy is set by comparing the detection reliability of the tower crane controller-side sensors and the motor-side sensors.

[0059] The present invention also provides a tower crane protection system, which includes a tower crane controller-side sensor, a motor-side sensor, and the aforementioned control device. The control device is communicatively connected to the tower crane controller-side sensor and the motor-side sensor, respectively.

[0060] Understandably, tower crane protection systems enable tower cranes to perform protective functions.

[0061] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0062] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0063] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for coordinated protection of a tower crane controller and a frequency converter, characterized in that, The tower crane controller and frequency converter coordinated protection method includes: Receive tower crane protection start signal; In response to the tower crane protection start signal, the tower crane can be protected by selecting either tower crane controller control, frequency converter control, or a combination of tower crane controller and frequency converter control. The step of selecting tower crane protection mode—together controlled by the tower crane controller, controlled by the frequency converter, or jointly controlled by the tower crane controller and the frequency converter—in response to the tower crane protection start signal includes: In response to the tower crane protection start signal, the status of the tower crane controller-side sensors and the motor-side sensors is acquired, and based on the status of the tower crane controller-side sensors and the motor-side sensors, the tower crane is protected by a combination of tower crane controller control, frequency converter control, or joint control by the tower crane controller and frequency converter.

2. The tower crane controller and frequency converter coordinated protection method according to claim 1, characterized in that, The step of selecting between tower crane controller control, frequency converter control, or a combination of tower crane controller and frequency converter control to protect the tower crane based on the status of the tower crane controller-side sensors and the motor-side sensors includes: The status of the tower crane controller-side sensor and the motor-side sensor are determined separately. If the tower crane controller-side sensor is in normal working condition and the motor-side sensor is in fault condition, the tower crane controller controls and protects the tower crane based on the tower crane controller-side sensor. If the tower crane controller-side sensor is in fault condition and the motor-side sensor is in normal working condition, the frequency converter controls and protects the tower crane based on the motor-side sensor. If both the tower crane controller-side sensor and the motor-side sensor are in normal working condition, a priority strategy is determined to prioritize controlling and protecting the tower crane through the tower crane controller, or prioritize controlling and protecting the tower crane through the frequency converter, or jointly control and protect the tower crane through both the tower crane controller and the frequency converter.

3. The tower crane controller and frequency converter coordinated protection method according to claim 2, characterized in that, The priority strategy is set by comparing the detection reliability of the tower crane controller-side sensors and the motor-side sensors.

4. The tower crane controller and frequency converter coordinated protection method according to claim 1, characterized in that, The tower crane protection activation signals include variable load stop protection signal, load-following speed protection signal, brake failure protection signal, and luffing anti-sway protection signal.

5. A control device, characterized in that, The control device includes: The receiving unit is used to receive tower crane protection start signals; The control unit is configured as follows: In response to the tower crane protection start signal, the tower crane can be protected by selecting either tower crane controller control, frequency converter control, or a combination of tower crane controller and frequency converter control. The control unit is further configured to: In response to the tower crane protection start signal, the status of the tower crane controller-side sensors and the motor-side sensors is acquired, and based on the status of the tower crane controller-side sensors and the motor-side sensors, the tower crane is protected by a combination of tower crane controller control, frequency converter control, or joint control by the tower crane controller and frequency converter.

6. The control device according to claim 5, characterized in that, The control unit is further configured to: The status of the tower crane controller-side sensor and the motor-side sensor are determined separately. If the tower crane controller-side sensor is in normal working condition and the motor-side sensor is in fault condition, the tower crane controller controls and protects the tower crane based on the tower crane controller-side sensor. If the tower crane controller-side sensor is in fault condition and the motor-side sensor is in normal working condition, the frequency converter controls and protects the tower crane based on the motor-side sensor. If both the tower crane controller-side sensor and the motor-side sensor are in normal working condition, the tower crane is first controlled and protected by the tower crane controller according to the set priority strategy, or the tower crane is first controlled and protected by the frequency converter, or the tower crane controller and the frequency converter jointly control and protect the tower crane.

7. The control device according to claim 6, characterized in that, The priority strategy is set by comparing the detection reliability of the tower crane controller-side sensors and the motor-side sensors.

8. A tower crane protection system, characterized in that, The tower crane protection system includes tower crane controller-side sensors, motor-side sensors, and a control device according to any one of claims 5 to 6, wherein the control device is communicatively connected to the tower crane controller-side sensors and the motor-side sensors, respectively.

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