Research On Neutral Grounding Pattern's Operating Characteristic And Overvoltage Problem Of Independent Power System Medium Voltage Network

Neutral Grounding Pattern's Operating Characteristic of power system is Synthetic Technical Problems; it correlates with Voltage Grade on Power Network power network structure insulation level power supply reliability Relay Protection and electromagnetic interference.Recently, middle and high voltage Generator in the power system more extensive application, in particular the use of the large number of cable lines make Capacitive Current substantial increase.Arc The problems of Grounding Over-voltage and Ferroresonance Over-voltage become more serious. Ship power system the most extensive application of isolated neutral system does not help to suppress the overvoltage. As a result, it is an essential work to study new neutral grounding mode for Ship power system, which can insure the reliability of power supply, personal and equipment safety, and should be economic, simple and convenient in assemble and operation.On the basis of theoretical analysis, The paper builds the simulation model of Arcing Ground Over-voltage and resonance over-voltage produced by transmission Line disconnection and voltage transformer on PSCAD/EMTDC. Network structure of the ship power grid as an example, This paper analyzes arcing ground overvoltage and resonance over-voltage produced by transmission Line disconnection and voltage transformer of 2 neutral grounding modes i.e. neutral isolated, neutral grounded by resistance .The simulation results show that neutral point grounding through high-resistance will help to suppress the over-voltage. This paper expounds calculation method of high-resistance grounded distribution system and provides a theoretical references for selection of grounding apparatusCombination of research papers, Neutral grounding modes of medium voltage marine power system choose neutral grounded by high-resistance .This can effectively inhibit overvoltage,make the fault current within the allowed range, ensure power supply reliability, reduce insulation accidents to minimum, and is an ideal neutral grounding scheme.