Collaborative Protection And Self-healing Control For Distribution Networks

Smart grid is the future of power system, it integrates advanced sensing technologies, control methods, and communications into the electrical grid. Smart grid strategies not only makes the large grid interconnect more compactly, but pushes the distribution network evolution to provide opportunities for energy efficiency and better integration of distributed generation including renewables to reduce carbon emission. In current electrical grid, the variety of protection and control functions with different targets and independent processes, the inflexible collaboration restrict the future development.The dissertation focus on the improvement of protection and control system with functions collaboration and service restoration. The main contents contain:(1) Design collaborative protection and control system structure. In traditional protection and control system, the functions are consolidated in the hardware devices. Collaborative structure makes the functions working as mobile agents, and makes the hardware as resources which used to support the processions. Functions’serial processions are changed into network collaborative processions. New structure makes better use of redundancy information and computing power to improve the performance of protection and control system.(2) Research of collaborative protection mechanism and strategy. Multiple mobile agents form an autonomous collaborated system, any event can be seen by a group of agents. These agents can get a more accurate judgment by exchange information. Before the fault stable and calculation result get the setting value, the protection system can forecast the fault situation by multi-agent’s reactions. The judgment can be faster to some extent. The autonomous collaborated system will be helpful to fast fault location and reliability improvement.(3) Research of fast service restoration reconfiguration scheme. In consideration of the features of service restoration in distribution network and the algorithm of dynamic programming, the reconfiguration scheme can be combined into protection and control system. In this way, the service restoration can be faster and the outage time can be reduced. This part research focuses on fast reconfiguration algorithm, which can acquire the accurate optimal solutions rapidly with limited power allowance.(4) Research of service restoration based on cloud computing. Distributed collaborative computing can expand further into cloud computing which uses considerable computing resources in network for accelerating the optimal solution of network reconfiguration. The service task can be decomposed into multiple computing blocks for parallel distributed processing which with less calculating complexity. This method can prevent the curse of dimensionality and improve the reliability of power supply.