From The Frequency Control Based On Simulink Dynamic Load Lifting Mechanism

Crane has been used widely in the every walk of life. With the science and technology development and age advancement, crane has been developed by leap and bounds too, especially, it has been developed by leap and bounds in the timing; tradition crane which timing by adjusting resistance in rotor of the bobbin motor with drum-cam controller, which change inbeing curve of motor to timing aim. It can satisfy the uplift speed and ensure demand of fixing orientation. Speed of this timing changes greatly and does not steady in the middle to low efficiency,more consume,astaticism of capability and slip loop of motor, carbolic brush easy wear and tear and high maintaining expenditure. With the electric and electrical developing, system of transducer timing new crane that install PC technology, PWM technology/ vector counterchange technology and energy return technology was much more perfect.Our country cranes have been using the transducer to timing since 1980's, despite applied always transducer of V/F rate control, the new technology display powerful- advantage. Tranquilization of frequency conversion and no polar timing, easy control, economize energy peculiarity was accepted speedy and admit. This technology breakthrough from changing crane and apply at the big/small vehicle stepped machine. After get experience, it was used gradually in the crane industry. With the frequency conversion technology develop emphases of the crane industry put at the high-tech field and aim at the crane industry characteristic to research deeply the frequency conversion and no polar timing system.The frequency conversion and no polar timing system is more complex than timing system of tradition crane which timing by adjusting resistance in rotor of the bobbin motor, how do the system optimize,run reliably,maintain daily at anytime ,these need our to resolve at the first time. The transmission system must do transitory and high frequency to-and-fro movement, because of the crane-work character, which arose vibration and impact of the machine, this is named dynamic load. The paper establishes a motor model, a three-mass and two-degrees of freedom equivalent system and its dynamics equations, in order to research the dynamic performance of crane hoisting mechanism. On the basis of established mathematical model, it also simulates four typical situations of hoisting mechanism by SIMULINK. The validity of the simulation model is tested and the result proves that the method is valuable for engineering applications.