Development Of Calculation Software And Multi-level Protection Setting For Distribution Network

The accurate calculation of the relay protection set is the basis of ensuring the safe and stable operation of the power system.With the development of the power grid,its scale is bigger and bigger,and the wiring and operation mode is more and more complex.The traditional current protection has been unable to meet the current requirements of the complex distribution network’s secure operation.Therefore,it is necessary to establish a protection configuration and principle that can meet the urban distribution network.On this basis,we hope to develop a software for relay protection setting calculation that be suit for the current distribution network.According to the current situation of the development of distribution networks,and the application of simulation software in power system,a typical distribution network fault model through analysis,research and establish the protection mode of the distribution network and multi-stage differential with transition resistor,so that the development of the multi-level distribution network protection setting calculation program,including fault admittance matrix subroutine,triangular matrix decomposition subroutine,flow calculation procedures,including the transition resistance calculation program,and the design of the front interface.The protection setting calculation software can realize the graphical modeling of distribution network graphical,input the relevant parameters,operation mode and preset a variety of possible fault scenarios,and calculation and analysis,power flow calculation,short-circuit current calculation under different fault condition protection and different modes of setting network topology of distribution network,generation before and after the fault voltage of each node,each branch of the short circuit current and each device protection setting value of other state variables,provide the data source for the theoretical analysis,the distribution network protection device or test system.Finally,the IEEE12 node standard model is used to simulate the power flow and short circuit,and the results are compared with the given results.The results show that the developed power flow and short circuit calculation program has high accuracy.A typical distribution network model is also used to configure and calculate the multi-level differential protection.By analyzing the setting results,it is verified that the software can meet the needs of distribution network relay protection or test system for diversified simulation test data.