New IGCT Neutral-Point-Clamped Adjustable Speed Drives for High Power and Medium Voltage Industrial Applications

摘要

New medium voltage neutral-point-clamped IGCTs bring together state-of-the-art technologies in microelectronics and power switching devices. Advanced features and related benefits include:* Fully regenerative topology provides bi-directional power flow at unity power factor without VAR compensation equipment.* Minimum harmonic content is applied to the power grid without traditional harmonic filters.* High output frequency and related motor speed range offer the best motor solution choice.* Torque ripple is minimal.* Part count is minimal, and reliability is high compared to multilevel, parallel or series connection topologies using IGBTs.* Water cooling technology is used for the power bridge and innovative mechanical design.* C-language control software can easily be ported through any future updated platform.* Full integration with ARTICS (Ansaldo's real-time automation system) and full connectivity with other local controllers and systems available on the market is possible.* Torque and speed high dynamic regulation loops are offered.* Graphic MMI is unique.* Drive logic is easily implemented and updated through the IEC-1131 compliant ISAGRAF~(TM) package.* Windows-based PC tools are used for reduced training and start-up time, and advanced monitoring.In addition, the active front-end hardware is similar to the motor-side inverter, yielding the following advantages:* Response to load and line voltage changes is fast. If line voltage drops suddenly, the active rectifiers prevent overcurrents in rectifying and inverting operations. The active rectifier can also stabilize the DC voltage, maintaining the motor voltage if the line voltage is low.* The IGCT rectifier is actively modulated to reduce harmonic content. In most conditions separate harmonic filters are not required.* Power consumption is not reactive, reducing electricity costs and making it possible to improve the power factor of external equipment connected to the same network.