Protection And Control Scheme Of Active Distribution System Line

Currently, a large number of applications are distributed power in the distribution grid. It can not only effectively reduce the pollution of the environment, reduce energy consumption, and can improve the reliability and flexibility of power system operation and control. When large-scale distributed power access, and change the original structure of the distribution network, which makes power distribution network becomes more complex network systems. It is most likely caused due to access distributed power transmission circuit protection devices so that the sensitivity decreases, and may even lead to a mismatch protection device malfunction or other issues. By addressing these issues, to accommodate DG access to the distribution network. It is necessary to take the initiative to protect the distribution network line-depth analysis and research. Therefore, the main text of the following research areas:Secondly, the inverter control interface in the form of DG and topology were introduced to the constant power control (PQ control) DG fault current characteristics were studied; when multiple DG’s distribution network of three-phase short circuit fault occurs, taken to the fault current and voltage iterative calculation based on the analysis of the sequence network diagram and simulation.Then, analyze the distribution network of distributed power access impact on distance protection. According to DG fault current characteristic under the PQ control strategy, combined with the power grid single-phase ground fault Sequence Network, established adaptive distance protection tuning methods. The simulation confirmed that the tuning method can effectively satisfy containing distributed power distribution network of line protection requirements for future research group DG fault current characteristics and adaptive distance control strategy to protect other tuning methods provide a theoretical reference.Finally, in order to achieve better protection for active distribution network management, and avoid unplanned island. Initiative to establish a distribution network for line protection logic protection program, the new program by chapter analysis of the multi-DG fault current and voltage, an adaptive current protection circuit breaker with the direction of the line protection, and combined with the communication between the protection device between the protective device logical choice to disconnect the fault line, so as to achieve the purpose of implementing the protection of distribution lines. Through the establishment of the model simulation analysis, the results of the program to verify the distribution network for transmission line protection initiative has good applicability.