Insulation Coordination is a designing criteria for any electrical equipment which enables the design of an insulation for the equipment in such a way that it minimizes interruptions during steady state conditions and also minimizes... more
Insulation Coordination is a designing criteria for any electrical equipment which enables the design of an insulation for the equipment in such a way that it minimizes interruptions during steady state conditions and also minimizes damages in case of transient over voltages and this is done economically.
Insulation coordination of Ultra high voltage (UHV) system plays a vital role as the voltages in UHV are in the order of 1200 kV hence during faults when the voltage rises up to 7 p.u. the equipment under consideration can undergo heavy damages. To prevent these effects from happening and to understand the intensity of these effects these faults are simulated in ATP EMTP and its effects are observed and presented here. According the data obtained protection device are used to mitigate the overvoltages to acceptable Basic Lightning Impulse Insulation Level (BIL) and Basic Switching Impulse Insulation Level (BSL) ratings of the given transmission system.
The advent of sensitive electronic equipment, which requires high-quality electric power and, at the same time, is more susceptible to electromagnetic interference, poses new challenges for power system transient simulation techniques and... more
The advent of sensitive electronic equipment, which requires high-quality electric power and, at the same time, is more susceptible to electromagnetic interference, poses new challenges for power system transient simulation techniques and algorithms. Power transmission line networks, due to their vast physical dimensions, are the most critical components of a complex power system from the reliability point of view in relation to direct lightning strike. The majority of outages in transmission lines are caused by back-flashovers and the tower-footing grounding impedance plays an important role in this context. To have an accurate estimation of the overvoltages in transmission lines, electromagnetic transient (EMT) compatible equivalent circuits of the grounding electrodes has been developed in this paper and the effect of frequency dependent effects has been studied using Finite Element Method (FEM). The objectives of this paper are to accurately estimate the overvoltages/surge in the transmission lines, and to develop a model to predict back-flashovers. The developed models will significantly improve the accuracy of EMT analysis of lightning discharge and its impact on the complex power systems.
Electric field grading devices have great importance for both the electric power transmission and distribution systems. This paper presents an improved electric field grading device used in the medium voltage metal-enclosed switchgear.... more
Electric field grading devices have great importance for both the electric power transmission and distribution systems. This paper presents an improved electric field grading device used in the medium voltage metal-enclosed switchgear. The solutions have been carried out by using Ansys Maxwell 3D software. The structure of two electrodes designed as cylindrical and elliptical have been compared to determine the electric field grading device to be used in practice. The transient and steady-state analyses have been performed in both designs. The field grading device manufactured for the metal-enclosed switchgear has been tested according to IEC standards in a high voltage laboratory environment. This study revealed that the newly designed field-grading device can be used in the metal-enclosed switchgear more safely. It also encourages researchers to optimize the electric field distribution using different geometric structures and to create running conditions in smaller indoor environm...
Electric field grading devices have great importance for both the electric power transmission and distribution systems. This paper presents an improved electric field grading device used in the medium voltage metal-enclosed switchgear.... more
Electric field grading devices have great importance for both the electric power transmission and distribution systems. This paper presents an improved electric field grading device used in the medium voltage metal-enclosed switchgear. The solutions have been carried out by using Ansys Maxwell 3D software. The structure of two electrodes designed as cylindrical and elliptical have been compared to determine the electric field grading device to be used in practice. The transient and steady-state analyses have been performed in both designs. The field grading device manufactured for the metal-enclosed switchgear has been tested according to IEC standards in a high voltage laboratory environment. This study revealed that the newly designed field-grading device can be used in the metal-enclosed switchgear more safely. It also encourages researchers to optimize the electric field distribution using different geometric structures and to create running conditions in smaller indoor environm...
This paper presents the application of the multi-frame digital interconnection protection for co-generation systems. The multi-frame digital interconnection protection is constructed from two frequency frames, one frame to detect... more
This paper presents the application of the multi-frame digital interconnection protection for co-generation systems. The multi-frame digital interconnection protection is constructed from two frequency frames, one frame to detect islanding events and the other frame to detect faults on either side of the point-of-common-coupling (PCC). Islanding events are detected based on the wavelet packet transform high frequency sub-band, which is extracted from the d-q-axis components of the instantaneous 3φ apparent powers determined at PCC. The detection of faults, on either side of PCC, is achieved by extracting the magnitudes and phases of the high frequency contents present in PCC currents. The high frequency contents present in PCC currents are extracted by a phaselet filter bank that is composed of 6 digital high pass filters. The multi-frame digital interconnection protection is experimentally tested on a 3.6 kVA co-generation system for islanding events, different faults on both sides of PCC, and non-transient conditions. Test results demonstrate the ability of the proposed interconnection protection to initiate accurate, fast, and reliable responses to various types of transient disturbances.
