Three-level converter system

This article describes the design guidelines for the construction and control of three-level converters. Loss equations that assist in thermal design and device sizing are provided along with current estimates for sizing link capacitors. The primary commutation mechanisms and the relevant parasitic effects are identified. A low-inductance busplane design is presented for designs featuring dual IGBT modules, and low inductance snubber capacitor connections are shown. The DSP-FPGA platform used to control the prototype is described in some detail. The partitioning of the controls into slower control functions implemented in the DSP and the faster functions synthesized in the FPGA is described. This prototype and controller provided a very flexible base, which was used to verify various modulation strategies, control functions, and power flow regulation algorithms for NPC converters. The lessons learned from the design, build, and test of this converter system can be applied to prototype development for other power electronic converters and systems.

[1]  P. K. Steimer,et al.  Medium voltage drive converter for industrial applications in the power range from 0.5 MW to 5 MW based on a three-level converter equipped with IGCTs , 2000 .

[2]  Deepak Divan,et al.  Impact of IGBT behavior on design optimization of soft switching inverter topologies , 1993, Conference Record of the 1993 IEEE Industry Applications Conference Twenty-Eighth IAS Annual Meeting.

[3]  B. P. Schmitt,et al.  Retrofit of fixed speed induction motors with medium voltage drive converters using NPC three-level inverter high-voltage IGBT based topology , 2001, ISIE 2001. 2001 IEEE International Symposium on Industrial Electronics Proceedings (Cat. No.01TH8570).

[4]  S. Clemente A simple tool for the selection of IGBTs for motor drives and UPSs , 1995, Proceedings of 1995 IEEE Applied Power Electronics Conference and Exposition - APEC'95.

[5]  Dushan Boroyevich,et al.  A comprehensive study of neutral-point voltage balancing problem in three-level neutral-point-clamped voltage source PWM inverters , 2000 .

[6]  S. Munk-Nielsen,et al.  Simulation with ideal switch models combined with measured loss data provides a good estimate of power loss , 2000, Conference Record of the 2000 IEEE Industry Applications Conference. Thirty-Fifth IAS Annual Meeting and World Conference on Industrial Applications of Electrical Energy (Cat. No.00CH37129).