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Distribution of the geomagnetically induced currents between the neutrals of certain power transformers in the standard configuration power grids is investigated. The allowances at which the quantitative estimates of the geomagnetically induced currents are obtained are formulated. A spatial model that allows considering a geographical arrangement of the power transformers when calculating the geomagnetically...
The occurrence of DC Bias will affect the normal operation of power transformer, thus DC bias withstand capability of transformer is a prerequisite for stable operation of power system. In this paper, the DC current distribution model of transformer neutral point in Yichang area is established. Meanwhile, according to the transformer noise limit, the maximum current which is allowable to flow through...
A network consisting of a substation including its buried and aboveground components and its overhead transmission lines is analyzed using rigorous electromagnetic fields based analysis. The entire system is modeled and its performance during steady-state normal conditions and fault conditions is examined and discussed. A long section of a buried pipeline is also parallel to the transmission lines...
Utilities in the United States and Canada have done extensive analysis of the ground grid design for substations in order to limit step and touch potentials to safe values; however, few have analyzed the potential hazard and designed grounding systems for pad-mount transformers. Since the kVA size and voltage ratings of pad-mounts have increased and the exterior of these facilities are accessible...
Wind power plants use power transformers to step plant output from the medium voltage of the collector system to the HV or EHV transmission system voltage. This paper discusses the application of these transformers with regard to the selection of winding configuration, MVA rating, impedance, loss evaluation, on-load tapchanger requirements, and redundancy.
In order to limit short-circuit current and satisfy the need of relay setting, only part of the 220kV power transformer is grounded, so on the neutrals of ungrounded transformers will appear the over-voltage. Currently the value of over-voltage on transformer neutral point and the corresponding protection strategy is based on theoretical formula, this article use the PSCAD/EMTDC software to calculate...
The paper summarizes produce over voltage principle of 110 KV main transformer central point and problem in protect mode, suggest has grounding protection of low reactance and this method could protect main transformer in 110 KV transformer substation effectively.
Transferred voltages by the neutral grounding appear when a fault to ground occurs in the medium voltage network of the distribution system, when the primary and secondary neutrals are interconnected in the distribution transformers. This phenomenon is particularly important in systems with multigrounded neutrals where a local fault is "seen" by the whole circuit, because of the multiple...
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