The Research of Voltage Sharing and Redundant Fault-Tolerant of Chain STATCOM in High Magnetic Field

With the high-voltage reactive power compensation device needs cascaded topology is more and more used in cascade STATCOM, however with the increase of chain units, the complexity of the system and the failure rate is also increased, while each chain DC voltage balancing section also has been a hot issue chain STATCOM research. Based on the above problem, for a strong magnetic field superconducting reactive power compensation scheme in the research, we propose a three-tier grading control, to achieve a chain link STATCOM system are pressure and high voltage inverter technology into the field of the neutral point offset STATCOM systems, system failure by changing the upper equalizing control strategy to achieve the system only after a fault bypass unit link fault, without the same position relative to non-fault bypass link directly improve the utilization of the link units. Finally, simulation and verification of equalizing the neutral point offset tolerant strategy is correct and effective method proposed in this paper.