Application of Current Source Inverter Medium Voltage Variable Frequency Drives in Longwall Mining

摘要

Underground longwall mining becomes more and more productive worldwide. The increasing demand for higher production generates a necessity for higher performance of longwall machinery. In order to reach the required level of performance, the longwall equipment needs to be equipped with much better functionality. Variable Frequency Drives (VFDs) deliver a technology facilitating this significantly more effective operation of electrically driven longwall machines. The current source inverter (CSI) version of VFDs allows the positioning of VFDs outside of the face. VFDs can even be placed at a distance of several kilometers away, if the local conditions in areas surrounding the face are difficult. Additionally, the properties of CSI VFDs enable further improvement of functionality for machines like plows and armored face conveyors (AFCs) allowing e.g. an active braking with energy recovery. In recent years, Caterpillar Global Mining developed a medium voltage CSI drive. These VFDs now work at the Bogdanka coal mine in Poland, powering the extracting (plow) and conveying (AFC) longwall machinery. The following paper presents the properties and describes the operation of these drives at Bogdanka.