Novel Circuit and Method for Fault Reconfiguration in Cascaded H-Bridge Multilevel Inverters

In this project, Solar photovoltaic and wind turbine generators achieved 10% of US electricity generation in March 2017. This percentage is expected to increase in future years. The electricity generated from wind and solar sources requires power electronic circuits in order to make this energy available to the electric utility grid. Consequently, there is a need for improved fault detection and isolation in power electronic converters for maximizing the reliability of renewable energy sources. 

In addition, there will be power electronics needed for utility-scale battery storage systems to provide back-up energy for times of reduced wind and solar generation output and to provide blackstart capability for restoration after power outages. 

This paper presents a new and novel power electronic circuit and method for isolating faults in power electronic inverter-rectifiers. This paper provides a significant improvement compared to existing methods by isolating faulted devices and reconfiguring the converter in a manner that reduces the disruption of electricity delivery. In addition, this is achieved with minimal cost impact to the overall system.

Keywords: cascaded H-bridge (CHB), Fault reconfiguration.