| Abstract [eng] |
The past decade has seen the sudden rise of renewable generation all over the world and many countries have introduced policies to combat the climate crisis. Only a few utility firms, however, have engaged in research into the impact of renewable energy on the current power grid. Even those studies were primarily concerned with the power system's stability and dynamics, with little attention paid to the impact of power system protection changes owing to low inertia generation, not to mention the lack of interest in distribution systems. Using new communication technologies at the distribution level has become fairly popular. The cost of digitizing the existing substation has substantially reduced over the years and this has encouraged the utilities to focus more on distribution automation while only basic protection functionalities are being implemented. It is more economical and efficient to address the problems associated with the protection in existing infrastructure, as implementing an entirely new set of protection hardware will incur huge financial capital investments. So, adaptive protection is one of the best suitable solutions as it can effectively work on existing smart grid architecture. The requirement, implementation and advantage of this scheme are discussed in detail as part of this thesis. Many distribution companies use a power system analysis software such as ETAP / DIgSILENT to evaluate the protection system settings for their network. For the implementation of Adaptive protection, revised settings will be calculated for any major changes in the topology of the primary network using the same software and these settings will be stored inside the appropriate numerical relays as different group settings. IEC 61850 communication architecture can be used to detect the changes in topology or operation parameters of the network and subsequently the relevant group settings will be activated by Adaptive protection. The same philosophy is implemented on a distribution network from Alytus substation area and with the help of the Python API feature of the Powerfactory Adaptive protection, the algorithm was checked for different scenarios of DER integration in the network. The key element to detect DER integration in this project is implemented with the help of monitoring the breaker ON and OFF states. Using RMS simulations inside the python IDE environment the performance of the algorithm is validated. This process resembles the real-time simulation; however, it is not to be treated as equivalent to a real-time process as the calculations performed in RMS simulations are different from an actual real-time simulator. This theory may be thoroughly validated in laboratories using hardware in loop testing, such as the RTDS simulator or any similar. The same network can be constructed in these simulators, and a real-world numerical relay can be used to evaluate the scheme's operation and reliability in the event of integration errors. |
