Variable-frequency closed-loop control system for upgrading wound-rotor motor based on tower crane hoisting mechanism

Abstract

According to the frequency conversion closed-loop control system for upgrading the wound-rotor motor of the tower crane hoisting mechanism, the wound-rotor motor of the tower crane hoisting mechanism is in short circuit with the neutral end of the rotor, and the neutral end is arranged in front of the carbon brush, so that the wound-rotor motor is equivalent to a squirrel-cage motor; a variable frequency control driving system, a linkage operation console system, a variable frequency electric control driving system, a safety protection device, an encoder, an independent brake, a speed reducer and a winding drum are combined to achieve stepless speed regulation to drive the winding drum to complete lifting, and the problem that stepless speed regulation of a winding type motor of an existing tower crane hoisting mechanism cannot be achieved is solved. The stepless speed regulation device is suitable for upgrading the winding type motor of the hoisting mechanism of the tower crane to stepless speed regulation.

Description

Technical Field

[0001] The utility model relates to the technical field of motor frequency conversion control, in particular to an upgraded frequency conversion closed-loop control system based on a winding motor of a tower crane hoisting mechanism. Background Art

[0002] The speed regulation methods commonly used in tower crane hoisting mechanisms are traditional AC speed regulation, winding motor rotor series resistance plus eddy current regulation with electromagnetic clutch shifting comprehensive speed regulation, two winding motors with one rotor series resistance and the other motor energy consumption braking speed regulation, double winding motor rotor series resistance speed regulation, etc.

[0003] Their shortcomings are as follows: they all have step-by-step speed regulation, which causes a huge impact on the mechanical structure and can easily cause fatigue or damage to the steel structure; they use relay contactor control, and frequent starting and stopping can easily burn out the contacts and coils, resulting in a high electrical failure rate, poor reliability, and high maintenance costs; the speed regulation range is small, and the positioning accuracy is very poor; the safety factor is low, and the high requirements for grid voltage are not conducive to energy conservation and environmental protection.

[0004] In the above speed regulation method, the motor speed of each gear is fixed and cannot be adjusted steplessly. The start and stop impact of the motor is large, the grid voltage requirement in the workplace is high, and each gear is controlled by the attraction or disconnection of the corresponding contactor. A large number of contactors are used, the attraction frequency is high, the contacts are easily burned, and the failure rate is high. Utility Model Content

[0005] The technical problem solved by the utility model is to provide a frequency conversion closed-loop control system based on the upgraded winding motor of the tower crane hoisting mechanism, so as to solve the problem that the existing winding motor of the tower crane hoisting mechanism cannot be steplessly adjusted in speed.

[0006] The utility model adopts a technical solution to solve the above technical problems: based on the upgrading of the variable frequency closed-loop control system of the winding motor of the tower crane hoisting mechanism, it includes a linkage operation console system, a variable frequency electric control drive system, a safety protection device, a winding motor, an encoder, an independent brake, a reducer and a drum; the winding motor includes a built-in brake; the linkage operation console system is used to provide linkage operation control instructions to the variable frequency control system; the variable frequency electric control drive system is used to drive the winding motor according to the linkage operation control instructions, and the neutral end of the rotor of the winding motor is short-circuited; the safety protection device is used to feed back the safety signal to the variable frequency electric control drive system; the encoder is installed on the output shaft of the independent brake, and is used to check the actual speed of the winding motor, and feed back the actual speed to the variable frequency electric control drive system; the independent brake is installed on the reducer, and is used to strengthen the start-stop braking force; the reducer connects the winding motor and the drum.

[0007] Furthermore, the safety protection device includes a lifting limiter and a load limiter.

[0008] Furthermore, the linkage operation control instruction includes a direction instruction and a speed instruction.

[0009] Furthermore, the variable frequency electric control drive system is an ESD-T1 variable frequency drive.

[0010] Beneficial effects of the utility model: The utility model is based on upgrading the variable frequency closed-loop control system of the winding motor of the tower crane hoisting mechanism. By short-circuiting the neutral end of the rotor of the winding motor of the tower crane hoisting mechanism, and the neutral end is before the carbon brush, the winding motor is equivalent to a squirrel cage motor. In combination with the variable frequency control drive system, the linkage operation console system, the variable frequency electric control drive system, the safety protection device, the encoder, the independent brake, the reducer and the drum are realized to achieve stepless speed regulation to drive the drum to complete the lifting and lowering, thereby solving the problem that the existing winding motor of the tower crane hoisting mechanism cannot have stepless speed regulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 The utility model is a structural schematic diagram of an upgraded variable frequency closed-loop control system based on a winding-type motor of a tower crane hoisting mechanism. DETAILED DESCRIPTION

[0012] In view of the problem that winding-type motors cannot be steplessly regulated, the utility model proposes an upgraded variable frequency closed-loop control system based on the winding-type motor of the hoisting mechanism of a tower crane. By short-circuiting the neutral end of the rotor of the winding-type motor of the hoisting mechanism, where the neutral end is before the carbon brush, the winding-type motor is made equivalent to a squirrel-cage motor, thereby being able to be combined with a variable frequency control drive system to achieve stepless speed regulation.

[0013] like Figure 1 As shown, the frequency conversion closed-loop control system based on the upgrading of the winding motor of the tower crane hoisting mechanism includes a linkage operation console system, a frequency conversion electric control drive system, a safety protection device, a winding motor, an encoder, an independent brake, a reducer and a drum; the winding motor includes a built-in brake; the linkage operation console system is used to provide linkage operation control instructions to the frequency conversion control system; the frequency conversion electric control drive system is used to drive the winding motor according to the linkage operation control instructions, and the neutral end of the rotor of the winding motor is short-circuited; the safety protection device is used to feed back the safety signal to the frequency conversion electric control drive system; the encoder is installed on the output shaft of the independent brake to check the actual speed of the winding motor and feed back the actual speed to the frequency conversion electric control drive system; the independent brake is installed on the reducer to strengthen the start-stop braking force; the reducer connects the winding motor and the drum.

[0014] Specifically, the safety protection device includes a lifting limiter and a load limiter; the linkage operation control instruction includes a direction instruction and a speed instruction; the variable frequency electric control drive system can be an ESD-T1 variable frequency drive.

[0015] Working principle: The linkage operation console system gives linkage operation control instructions to the variable frequency electric control drive system. When the safety protection device is in normal condition, the variable frequency electric control drive system drives the winding motor according to the linkage operation control instructions to achieve stepless speed regulation. The encoder checks the actual speed of the winding motor and feeds back the actual speed to the variable frequency electric control drive system. After comparing it with the given speed instruction, the speed is controlled and adjusted by the deviation signal, thus forming a speed negative feedback closed-loop control system. The winding motor transmits power to the drum through the reducer to complete the lifting and lowering of the tower crane hoisting mechanism.

[0016] The utility model improves the winding motor of the hoisting mechanism of the tower crane, that is, the neutral end of the rotor of the winding motor of the tower crane hoisting mechanism is short-circuited, and the neutral end is before the carbon brush, so that the winding motor is equivalent to a squirrel cage motor, and this is combined with a variable frequency electric control drive system to achieve stepless speed regulation, which can realize operations with precise control and positioning requirements, and the soft start and soft stop functions reduce the mechanical transmission impact, which can significantly improve the bearing performance of the steel structure and extend the service life of the crane; the motor can output full torque at zero speed, and even if the brake is loose or fails, the heavy object will not slide down, ensuring the safety and reliability of the system; in particular, it can also be matched with a special load weight measurement and control instrument and equipped with corresponding software, and the lifting speed can be switched with the load weight change to achieve the operation requirements of "fast for light load and slow for heavy load", and because the variable frequency electric control drive system has an automatic energy-saving operation mode, it can greatly improve the power factor of the system and the working efficiency of the whole machine, and the energy-saving effect is remarkable.

Claims

1. Based on the tower crane hoisting mechanism winding motor upgrade variable frequency closed-loop control system, it is characterized by: It includes a linkage operation console system, a variable frequency electric control drive system, a safety protection device, a winding motor, an encoder, an independent brake, a reducer and a reel; the winding motor includes a built-in brake; the linkage operation console system is used to provide a linkage operation control instruction to the variable frequency control system; the variable frequency electric control drive system is used to drive the winding motor according to the linkage operation control instruction, and the neutral end of the rotor of the winding motor is short-circuited; the safety protection device is used to feed back the safety signal to the variable frequency electric control drive system; the encoder is installed on the output shaft of the independent brake, and is used to check the actual speed of the winding motor, and feed back the actual speed to the variable frequency electric control drive system; The independent brake is installed on the reducer to enhance the start-stop braking force; The reducer connects the winding motor and the reel.

2. The frequency conversion closed-loop control system based on the tower crane hoisting mechanism winding motor upgrade according to claim 1 is characterized in that: The safety protection device comprises a lifting limiter and a load limiter.

3. The frequency conversion closed-loop control system based on the tower crane hoisting mechanism winding motor upgrade according to claim 1 is characterized in that: The linkage operation control instruction includes a direction instruction and a speed instruction.

4. The frequency conversion closed-loop control system based on the tower crane hoisting mechanism winding motor upgrade according to any one of claims 1 to 3, characterized in that: The variable frequency electric control drive system is an ESD-T1 variable frequency drive.

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