The invention is applied to the technical field of
electrical control, and provides a device and a method for controlling a slewing mechanism of a
tower crane. The device for controlling the slewing mechanism of the
tower crane is composed of a general frequency converter, an alternating-current
brake circuit, a slewing motor, a direct-current
brake circuit, a forward
control circuit, a reversal
control circuit, an intermediate-speed
control circuit, a high-speed control circuit and a braking control circuit. At the moment of starting, the initial frequency of the general frequency converter is regulated and the
speed reduction time is regulated when the output frequency of the general frequency converter is reduced, thus the torque of a
tower body is released; under the control of the direct-current
brake circuit, the swinging of a lifting arm and the torque of the tower body are released fully; meanwhile, the general frequency converter provides brake signals of the alternating-current brake circuit and brakes a slewing motor, and the lifting arm stops stably; and the comprehensive benefits of convenience in operation, long repairing and maintaining cycle and
energy source conservation are realized by utilizing each function of the general frequency converter.