Interfacing of Power System Simulators With Representation of Protection Relay Software

Abstract

-Modelling and simulation software developed for analysing protecting relaying applications and relay design concepts in energy distribution is described inside the paper. The aim turned into to increase an open device that is simple to use and permits simple destiny expansions. Easy to use presumes that the software program should be appropriate for teaching functions that is accomplished by way of introducing new libraries of sign assets and relay elements evolved in the MATLAB / SIMULINK environment mixed with the SIMULINK / Sim Power Systems, the stated libraries enable an expansion of research aimed toward higher knowledge protective relay design strategies and processes and related programs in power gadget.Keywords -MATLAB, SIMULINK, Protective relay. I. INTRODUCTIONInside the MV networks in Croatia there are 3 methods of substation (transformer) neutral point grounding remedy: isolated, low-ohmic grounded and, from multiple years in the past, resonant grounded. MV distribution networks are especially radially operated. With an purpose to define the criteria for appropriate neutral treatment selection relying on the substation and MV network type, a top level view take a look at has been carried out currently. choice criteria in the have a look at considered: Technical functions of all 3 treatments regarding the earth-fault currents, over voltages and network operation based on literature, measuring, computer evaluation and operation experiences; Human safety necessities and rules (touch voltages), heath and voltage stresses and interferences with telecommunications strains; network importance (number and form of connected clients), length (period of galvanic related traces), kind (cable to overhead lines ratio, kind of poles and sorts of cable junctions and screens); community reliability (SAIFI and SAIDI); Earth systems necessities regarding earth fault currents and soil resistivity. Each criterion has been economically evaluated concerning capital and operation expenditure and then value-benefit analyses were made. The effects of those analyses are criteria for adequate neutral treatment choice regarding mentioned capabilities, requirements and policies. The examine also emphasized the need for guidelines protection concerning a brand new manner of operation and safety relay requirements as well as harmonization with eu norms. The want for implementation of recent safety methods and primary measuring gadget (contemporary and voltage transformers) coordination have additionally been taken into consideration and analysed. The evaluation done and the results carried out are described in this newsletter. In the scope of the observe, measurements of pre-fault and earth-fault currents and voltages were conducted in 10 kV and 20 kV distribution networks provided from HV/MV substations. Earth-faults have been executed with different fault resistances and types in addition to by way of using distinct neutral factor grounding strategies: isolated, low-ohmic resistive and resonant.