Lifting and transportation equipment as a national industrial production of special equipment, widely used in various industries, with the continuous improvement of industrial production of crane speed performance requirements, commonly used conventional crane speed control method due to the winding rotor asynchronous motor of the collector ring And brushes are prone to failure, coupled with the use of a large number of relays and contactors, resulting in a large amount of on-site maintenance, high failure rate of the speed control system, poor comprehensive technical indicators, can no longer meet the special requirements of industrial production.

In recent years, with the continuous development of frequency conversion technology, the performance of frequency inverters has been increasing, the features of frequency conversion and speed control mechanical properties are hard, the speed range is large, the precision of speed regulation is high, the stability is good, the control is easy, the energy saving and other characteristics are satisfied, and it can be well satisfied. Lifting equipment is safe, stable, reliable, with good and reliable operation, and maintenance-free requirements. It has quickly achieved breakthroughs in the crane industry and is widely used.

At present, among the many inverter brands, there are not many products that can fully meet the lifting industry characteristics. The main difficulty is that because of the particularity of the crane, the inverter for the crane must have some special properties: the dynamic response is fast to meet the crane The demand for rapid changes in load; wide range of speed control capabilities, can make the motor output 2~3 times the rated torque of the output torque near low speed; can withstand the impact of current and ensure the sudden change in the potential energy load Reliable operation under continuous mechanical vibration environment; Renewable energy of the motor can be reliably released at the time of deceleration and braking. The current capacity as a brake unit needs to be larger; with a highly reliable protection system, special attention must be paid to the hoisting mechanism. After the brake is released or before the brake, it prevents the “slippery hook” control; it has a powerful monitoring system, which can realize the fault alarm and fault analysis of the system through monitoring various parameters.

Take Delta VFD-C2000 inverter as an example to explain briefly how to solve these difficulties. The FOC PG control application of Delta VFD-C2000 inverter can obtain stable speed output and optimal dynamic response through motor parameter learning function with speed feedback signal; it can accurately control output torque within a wide range of 0.05Hz~50Hz. Large current capacity, can withstand up to 200% of the rated current impact; with unique energy recovery technology; perfect protection system, with stall protection function, can prevent acceleration, deceleration and running stall conditions, but also have over-current, Over-voltage, under-voltage and input phase loss protection, as well as over-temperature, overload, over-speed, motor fault protection and other functions. C2000 built-in PLC function and CANopen protocol, together with Modbus, Profibus, DeviceNet and other high-speed communication networks, can achieve real-time data monitoring.

With the continuous development of power electronic technology, the inverters in the lifting machinery industry have increasingly exhibited excellent control and speed control performance, high efficiency, and easy maintenance. With the continuous decrease in the price of inverters, frequency control will become A preferred speed regulation scheme for hoisting machinery, the market size of inverters in the hoisting machinery industry will continue to expand.