Abstract : This paper introduces some special functions built into the ATV58 frequency converter software design, such as braking logic sequence control and low-frequency high torque, which are essential in the lifting industry. The application of these special functions in hoist cranes and overhead cranes is also demonstrated. Keywords : Frequency converter, hoist crane, overhead crane 1 Introduction Variable frequency speed control technology is a new type of electric drive speed control technology that has developed rapidly since the 1980s. Variable frequency speed control devices are used for speed control of AC asynchronous motors. Their performance surpasses that of voltage regulation, pole changing speed control, slip speed control, and AC series pole speed control, and they are simple in structure, stable and reliable, have a wide speed range, and offer significant energy savings. They have become a common method in speed control systems. With the increasing maturity of frequency conversion technology, the application of frequency converters in lifting equipment is becoming more and more widespread. This paper uses Schneider Electric's ATV series frequency converter as an example to introduce the application of frequency converters in hoist cranes and overhead cranes. [b]2 Application of Frequency Converters in Hoist Cranes 2.1 Special Characteristics of Conical Motors[/b] In China, hoist cranes typically use special conical rotor motors. Internationally, dual-speed motors are generally used in this application. Conical rotor motors have a more complex structure than ordinary motors, but they are highly reliable when stopping, requiring no external mechanical braking mechanism. They rely on internal spring force for braking. Therefore, they are widely used in small-tonnage lifting equipment in China. The principle of conical motors is similar to that of ordinary motors, the difference being that their starting and stopping actions differ. During startup, the motor requires a large excitation current to pull the rotor to the normal position; the starting current is larger than that of ordinary motors. When stopping, the motor loses power, and the motor itself stops using internal spring force. However, due to the production process requirements of some industries, it is desirable for the motor to be speed-adjustable according to process requirements. This creates a two-speed problem. Ordinary frequency converters cannot meet the starting performance requirements, resulting in the inability to pull the motor rotor to the working position during startup, thus preventing operation. [b][align=center]For details, please click: Application of Frequency Converters in Lifting Equipment[/align][/b]