Crane constrained by the drive difficult to meet the special requirements of developing

Lifting and transport equipment as the national industrial production of special equipment, widely applied to various industries, with the industrial production of the crane speed performance requirements continue to increase, the  steel crane  speed control method commonly used traditional wound rotor induction motor due to its collector ring and brush prone to failure, along with a large number of relays and contactors are used, resulting in a large amount of on-site maintenance, speed control system failure rate is high, comprehensive technical indicators are worse, has been unable to meet the special requirements of industrial production.

In recent years, with the continuous development of inverter technology, inverter performance and increasing the mechanical properties of hard-frequency control, speed range, speed and high precision, good stability, easy to control and energy-saving features, can well meet lifting equipment safe and stable, reliable, good operability reliable,hoist gantry crane maintenance requirements, rapid breakthrough in the crane industry and widely used.

Currently, in many inverter brands, can fully meet the needs of lifting products industry characteristics are not many, the main difficulty is due to the particularity of the crane, crane drive must have some special properties: fast dynamic response, in order to meet the crane dramatic changes in load demand; wide range of speed control, the speed can cause the motor output segment around 2 to 3 times the rated torque of the torque output of the peak; can withstand dramatic changes due to the potential energy of the load current impact and guarantees appear in a continuous and reliable operation of mechanical vibration environment; decelerating the motor during braking can be reliably released renewable energy, as the current capacity of the brake unit to be larger; protection system with high reliability, for the lifting mechanism, the need to pay particular attention to mechanical after the brake is released immediately before or brake to prevent the "slip hook" of the control;bridge gantry crane possess powerful monitoring system, through the monitoring of implementation of various parameters of the system failure alarm and failure analysis.