A self-balancing space vector switching modulator for three-level motor drives

This paper describes on how to formulate a self-balancing space vector modulator for the three-level neutral point clamp topology typically used for high power induction motor drives. Besides the space vector modulation principle being used to calculate pattern times within one control update cycle, several other techniques are proposed in order to obtain a production quality modulator. These include a pivot point concept to be used for pattern selections in order to achieve minimum switching losses, techniques for neutral point voltage balancing, power device minimum on/off time guarantee, adjacent state switching, and sine triangular equivalent etc. The derived modulator was successfully implemented with a 3500 hp motor drive. Lab test results show the effectiveness of the modulator.

[1]  Dongsheng Zhou,et al.  Dead-time effect and compensations of three level neutral point clamp inverters for high performance drive applications , 1997, Proceedings of the IECON'97 23rd International Conference on Industrial Electronics, Control, and Instrumentation (Cat. No.97CH36066).

[2]  Seung-Ki Sul,et al.  A new discontinuous PWM strategy of neutral-point clamped inverter , 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).

[3]  V. Blasko,et al.  Analysis of a hybrid PWM based on modified space vector and triangle comparison methods , 1996, IAS '96. Conference Record of the 1996 IEEE Industry Applications Conference Thirty-First IAS Annual Meeting.

[4]  Dong-Seok Hyun,et al.  A novel PWM scheme for a three-level voltage source inverter with GTO thyristors , 1994, Proceedings of 1994 IEEE Industry Applications Society Annual Meeting.

[5]  Rae-Young Kim,et al.  A novel SVPWM strategy considering DC-link balancing for a multi-level voltage source inverter , 1999, APEC '99. Fourteenth Annual Applied Power Electronics Conference and Exposition. 1999 Conference Proceedings (Cat. No.99CH36285).

[6]  A.M.N. Lima,et al.  A space vector PWM method for three-level voltage source inverters , 2000, APEC 2000. Fifteenth Annual IEEE Applied Power Electronics Conference and Exposition (Cat. No.00CH37058).