Abstract : This paper presents an example of the application of supercapacitors in frequency converters. Using supercapacitors to store the regenerative energy of electric motors has proven effective in mine hoist frequency converters, and several such devices are already in normal operation in mines. Keywords : Supercapacitor, Regenerative Energy, Frequency Converter, Mine Hoist 1 Introduction Several domestic brands of supercapacitors have entered the market. It is the responsibility of OEMs to promptly apply this new and excellent passive energy storage element to electronic and electrical equipment. Supercapacitors (or Ultra-capacitors) have been commercially used abroad for over 20 years. Their superior characteristics, such as extremely high power density, extremely short charging time, and extremely long service life, are unmatched by conventional capacitors, and their application prospects are very broad, especially in the power supply industry. Our company is a professional frequency converter manufacturer and has conducted in-depth research on processing the regenerative energy of electric motors. The purpose of this research is to promote the application of frequency converters in mine hoists. Variable frequency drive (VFD) systems are widely used in pump and fan loads, and their adoption is gaining momentum. This is because people have a deep understanding of the superior speed control performance and significant energy-saving effects of VFDs. However, the promotion of VFD systems in hoisting loads has not been as smooth or widespread as in the above two types of loads. The reason is simple: hoists, especially large-capacity hoists, place extremely high demands on VFDs, making their promotion in this field very risky. For example, mining hoists operate continuously for 24 hours; even a ten-minute downtime can disrupt operations, causing trouble and losses in production. Technically, they require VFDs to have a starting torque more than twice the rated torque, a low-frequency torque more than 1.6 times the rated torque, and a braking torque greater than the rated torque. Sometimes, very high acceleration torque is also required. Furthermore, four-quadrant operation is also required. When lowering heavy objects, the rotor's speed may exceed the speed of the stator's rotating magnetic field due to gravity. The motor then becomes a generator, and the regenerated energy increases the bus voltage. This energy must be quickly transferred, either fed back to the grid or dissipated using energy-consuming resistors. Furthermore, the large fluctuations in the mine's power grid and the high dust content in the air pose significant threats to the reliability of the frequency converter. These factors make the implementation of frequency conversion speed regulation for hoists difficult and slow. [b][align=center]For more details, please click: Application of Supercapacitors in Mine Hoist Frequency Converters[/align][/b]