HANDOVER OF PROTECTIONFUNCTIONS IN A HETEROGENOUSSYSTEM TO IMPROVE EFFICIENCY

Abstract: Electricity is an essential element in today’s society, and to ensure its availability, Intelligent Electronic Devices (IEDs) are installed in power grids to detect and isolate faults by running protectionfunctions. These devices run very complex configurations with strong real-time requirements, andcan reach very high CPU utilisation’s that might affect timing requirements. However, many ofthese devices are built with other specific processors in the SoC, such as DSPs. This thesis evaluates possible ways to offload the execution of certain CPU protection functions to the DSP, toimprove system efficiency and allow more complex configurations to be executed. For this purpose,two frameworks are proposed and evaluated that enable communication and synchronisation betweenheterogeneous processors to perform simultaneous execution of functions on both processors. Thefirst framework allows the extraction of the execution of individual functions, while the secondframework performs the extraction of the execution of an entire process. The proposed frameworksare evaluated over general system configurations and Hitachi Energy product-specific configurations. Both give favourable results, being the first framework more effective to reduce the CPUutilisation of the general cases and specific cases of the current product, resulting in a reductionof CPU usage up to 14%. Although the second framework would allow the development of moreoptimal systems if the system were designed with this framework into account ensuring a high DSPutilisation, allowing configurations that would be equivalent up to 111% CPU usage without the useof the frameworks.