The invention specifically relates to a control method for a force-variable jib crane using a vector voltage-variable frequency-variable frequency converter as a power supply, belonging to the field of crane control. The control method provided by the invention comprises the following steps: indirectly measuring the load torque of a lifted heavy matter through measuring of direct current power and output frequency of the frequency inverter, and using the measured load torque and the rated power of a lifting motor as limited conditions so as to obtain maximum operating frequency of the lifting motor; and determining the operating frequency of the lifting motor by coaction of speed control gears, a crane jib and safe load torque. The control method in the invention enables a crane system to work in a rated torque and a rated power, thereby achieving the dual purposes of ensuring safety and improving efficiency; meanwhile, the lifting load torque of the crane is less than or equal to the safe load torque, so the crane cannot overturn. According to the invention, through measuring of intrinsic parameters of the frequency inverter, the number of sensors in a traditional crane is reduced, measuring accuracy is improved, and system complexity and cost are lowered; thus, the crane system is simpler, more precise and more efficient and has higher reliability.
Control method for force-variable jib crane using vector voltage-variable frequency-variable frequency converter as power supply
2015-08-05
Patent
Elektronische Ressource
Englisch
IPC: | B66C Krane , CRANES |
Europäisches Patentamt | 2015
|Variable carrier switching frequency control of variable voltage converter
Europäisches Patentamt | 2018
|VARIABLE CARRIER SWITCHING FREQUENCY CONTROL OF VARIABLE VOLTAGE CONVERTER
Europäisches Patentamt | 2017
|VARIABLE CARRIER SWITCHING FREQUENCY CONTROL OF VARIABLE VOLTAGE CONVERTER
Europäisches Patentamt | 2017
|Variable carrier switching frequency control of variable voltage converter
Europäisches Patentamt | 2019
|