For general-purpose variable frequency drive (VFD) applications, Ningbo CRRC Times Sensing provides a full portfolio of Hall-effect current sensors that deliver an integrated current sensing solution covering both the main power circuit and drive-level protection, fully meeting the multi-stage sensing requirements inside VFDs. The closed-loop Hall XXR1 series, open-loop Hall XXC series and closed-loop Hall NT series are deployed at the rectifier input stage, DC bus and inverter output stage of the VFD respectively. They accurately measure line-frequency input current, DC bus current and variable-frequency output current, providing highly reliable real-time feedback for vector control algorithms, DC bus voltage regulation and main circuit overcurrent protection. The open-loop integrated chip-type NHC35XX series and closed-loop Hall XXP series feature a compact form factor and high integration, making them suitable for collector current sensing of IGBT power modules and fast drive-side overcurrent protection, satisfying the high-density design requirements of power units. With excellent electromagnetic immunity and stable performance across a wide operating temperature range, the full sensor range adapts to the complex electromagnetic environment inside VFDs, ensures high-precision operation and long-term reliability of variable speed drive systems, and is widely applied in industrial drives, motor speed control and automation equipment.