The Calculation And Analysis Of Internal Over-voltage Based On PSCAD Software In500kV Power Transmission System

With the increase of voltage level, the fault of transmission line is more serious. In order tomeet the need of initialdesign and late start debugging in500kV project system, thispaper describesthe model parameters required, calculation formula, the function model based on the practicalengineering. The analysis of modeling and Simulation is base on PSCAD electromagnetic transientsimulation software in this paper. Analysis of the normal mode commissioning and maintenance ofthree kinds of power frequency over-voltage from Chunkunshan-Qixiaying double loop linebreaking new500kV substation of Wuchuan in the500kV power transmission project; Using theMultiple run module for Calculation and analysis of two cases with single line and rec-losing over-voltage under the realization ofMonte Carlo method; Byusing FAULTG, ARC module setting faultsequence, arc resistance, arc length on secondary arc current and recovery voltage simulationcalculation and analysis of the various factors, reactor compensation arrangement, soil festivityeffect.For the phenomenon of producing the high induced voltage and current may be caused byearthing switch switching process breakdown when the500kV double circuit lines on the sametower with shunt reactor circuit in one operation and a power back to the high resistance does notexit, design grounding switch model of double circuit lines on the same tower to match the highinduced voltage and current.Most of the existing literature focus on the analysis of the internal mechanism of over-voltagesuppression measures, analysis of the qualitative factors by formula derivation method, EMTP andBPAalgorithm, but the lack ofquantitative data analysis and comprehensive analysis.For electric power system PSCAD modeling, we must first understand the background of theengineering research, then collect the relevant parameters, such as the voltage level and capacity ofsubstation, and a variety of modes of flow diagram, the line is parallel reactor, line length and wiremodel. Steady state with accurate system parameters can accurately simulate the actual constructionthe situation analysis to lay the foundation for internal transient over-voltage in electric powersystem. Therefore, to build the accurate equivalent power system is a prerequisite to calculate internalover-voltage in the PSCAD.In this paper, the electromagnetic transient simulation software based on the PSCAD, twomethods to establish the equivalent model is presented, one is the calculation of line positivesequence impedance, zero sequence impedance, transformer substation power supply voltage andphase by the formula method, second kinds of methods is how to obtain these parameters fromoutput of the DAT in the BPA, and the simulation of circuit with inputting parameter in Bergeronand the line tower model. The measurement part of the set voltage, current, power, reactive powerand voltage measuring device, through controlling circuit angle and other parameters at the end ofthe first power supply to achieve flow control, thus completing the simulation and analysis ofvoltage and the internal model. In this paper, the selection of electrical equipment, over voltageprotection, re-closing time is determined to provide a theoretical basis and data support, which has acertain guiding significance on the commissioning, start-up and operation in500kV transmissionand distribution engineering.