Impact of neutral grounding system on short circuit current in Iraqi power system

A grounding system must be utilized to provide a tiny amount of resistance channel to the earth to assure safety and prevent faults. When an unplanned or unanticipated above-normal potential current or voltage spike occurs the grounding system is crucial for completing an electrical path to the ground. There are many grounding techniques that can be used to ground the neutral point in the power system. A grounding system may be created by using a solid conductor, via components like reactance or resistance, ungrounded, etc. However, in case of the solid grounding system, there is no impedance in the neutral route; the protection systems will detect a high fault current. In this case, high resistance must be applied to the neutral grounding channels to reduce the fault current, but the voltage of the healthy phases will be greater than the nominal phase voltage and the protection system cannot sense the fault current. One of the most efficient and economical grounding system methods is the effectively grounding system. For the purpose of achieving this system, two basic conditions are required The ratio of zero-sequence reactance to positive sequence reactance cannot be greater than three, and the ratio of zero-sequence resistance to positive reactance cannot be greater than one, regardless of the operating circumstances or the generator’s capacity. This research wills exanimate the grounding system of the Iraqi power system and shows there impact on the single and three phase fault current. Power System Simulation for Engineering (PSS/E) is used in this research to evaluate the impact of the grounding system on the short current in the Iraqi power system.