Protection systems are important for the continuous operation of large Static Converters as they are used in AC-Drives, HVDC and large rectifiers. Furthermore, if the application requires high availability some degree of redundancy is necessary to provide resilience to a fault. Whether the fault occurs due a critical malfunction in a critical device or due errors in the control scheme, it is necessary to maintain the power flowing at normal rate using the remaining modules. This situation can occur in grouping of Non-Conventional Renewable Energy (NCRE) systems or in modular high-power drives. For example, if a modular AC/AC link without a smart protection system suffer the failure of one module, it will cause sudden changes in the power delivery to the load as well as transient perturbations in input/output current/voltages. To avoid these issues, modular converters and groupings of NCRE systems will be provided with smart protections using fast communication channels and a well-designed logic to reconfigure the system after a failure detection. In this work an intelligent protection system for modular current source based converters is presented. Smart protections are placed in each individual DC link and connected to a supervisor stage using a CAN BUS standard. The procedure to overcome a single module failure start with a trip signal triggering the hot swapping procedure which allows the disconnection of the fault module and the connection of a redundant module. The main advantages granted by this system are: (a) increase in the availability of equipment and (b) a constant energy flow by replace quickly a failed module. Theoretical considerations and design procedures are validated using simulations and experimental results.
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