Research On RMU Feeder Protection Simulation Analysis Platform Based On MATLAB

Currently, the simulation research on distribution line has remained mostly in a certain principle or algorithm, and it’s less on the factors which have little influence on the principle or algorithm or which have yet been taken into account. It has well-targeted features and this also leads to some disadvantages. It requires to build the common simulation models every time such as lines, sources, transformers and so on, which wastes unnecessary time and energy. What’s more, the simulation is almost open-loop so that it doesn’t reflect the situation where the switch such as breaker has already moved. As a consequence, it is short of practical application.In order to be convenient to test on cable distribution circuit closed-loop protection simulation, analysis the protection and also make the abstract teaching on protection imaged, this paper establishes a platform based on MATLAB software for simulating and analyzing RMU (Ring Main Unit) feeder protection in distribution network, and surrounds the establishing the platform and makes a research from following respects:(1) The structure and principle of the current RMU feeder protection devices are analyzed, including the structure of hardware and various algorithms of obtaining characteristic quantity and diagnosing fault. These provide references and theoretical basis for platform’s design and establishing.(2) According to the platform’s functional requirements, its general scheme and great detail are proposed.(3) The crucial problems in platform’s development process are solved, including the closed-loop control, dynamic real time simulation and man-machine interface.(4) The development of the platform. First, design each of the functional modules of the platform in detail; and then realize it by the development tools such as S function, subsystem; finally, make each function model and interface to build into a complete, working platform.(5) Parameters setting of every model in platform are introduced detailedly and the platform’s function is checked by simulation examples.Analysis of the various fault types simulation results show that, this platform can realize the simulation for different fault occurring in cable feeder in distribution network; simulate feeder protection device’s workflow, accurately detect fault and do the corresponding action; simulate the power grid’s running state after the switch moves.