Introduction of a series-connected hybrid multi-converter system

This paper proposes a hybrid multi-converter system aiming at a large capacity high voltage high efficiency converter system with being free from harmonies in its input/output. The system can consist of n-1 (n: integer) GTO inverters and a single neutral-point-clamped IGBT inverter connected in series by n output transformers. The GTO converters operate in a square-wave switching mode, while the IGBT converter operates in a PWM switching mode. The former produces a base part of the resultant output voltage. The latter not only produces an additional part of the resultant output, but offsets the harmonic components generated by the GTO converters. A basic voltage control strategy for the system is proposed, and its validity is verified by experimental results.

[1]  Kenichi Suzuki,et al.  Development of self-commutated SVC for power system , 1993 .

[2]  Fujio Ishiguro,et al.  Development of a large static VAr generator using self-commutated inverters for improving power system stability , 1991 .

[3]  Kenichi Suzuki,et al.  Control Method for 50MVA Self-Commutated Static Var Compensator , 1997 .

[4]  S. Fukuda,et al.  Introduction of a hybrid multi-converter system and its control strategy , 2002, Proceedings of the Power Conversion Conference-Osaka 2002 (Cat. No.02TH8579).

[5]  Shoji Fukuda,et al.  Control strategy for a three phase series-connected hybrid inverter system , 2001, 2001 IEEE 32nd Annual Power Electronics Specialists Conference (IEEE Cat. No.01CH37230).

[6]  T. Nakajima,et al.  Minimum harmonics PWM control for a self-commutated SVC , 1993, Conference Record of the Power Conversion Conference - Yokohama 1993.