Zero-sequence voltage injection for DC capacitor voltage balancing control of the star-connected cascaded H-bridge PWM converter under unbalanced grid
- Resource Type
- Conference
- Authors
- Lee, C.-T.; Chen, H.-C.; Wang, C.-W.; Wu, P.-H.; Yang, C.-H.; Cheng, P.-T.
- Source
- 2014 IEEE Energy Conversion Congress and Exposition (ECCE) Energy Conversion Congress and Exposition (ECCE), 2014 IEEE. :4670-4676 Sep, 2014
- Subject
- Fields, Waves and Electromagnetics
Capacitors
Voltage fluctuations
Pulse width modulation
Equations
Mathematical model
Automatic voltage control
Modular Multilevel Cascaded Converter
PWM cascaded converter
STATCOM
Capacitor voltage balancing control
Low-voltage ride-through (LVRT)
Zero-sequence voltage injection
- Language
- ISSN
- 2329-3721
2329-3748
This paper presents a dc capacitor voltage balancing convtrol method for the star-connected cascaded H-bridge PWM converter in the static synchronous compensator (STATCOM) applications. The proposed control utilizes the zero-sequence voltage injection to accomplish the dc capacitor voltage balancing, and the this operation of zero-sequence voltage does not affect the original reactive power control. The proposed control method also works for the low-voltage ride-through operation. The control algorithm is verified with a 220-V 1kVA STATCOM based on star-connected cascaded PWM converter, and the test results verify that all the dc capacitor voltages are still regulated at the commanded value even as the grid voltage sag occurs.