Sensitivity analysis of a power system against overvoltage was performed. The analysis took into account the origin of the overvoltage, the grounding resistance magnitude and overvoltage injection point. The IEEE 13 bus test feeder system was implemented in EMTP-ATP and lightning and switching overvoltages were applied. Three cases were evaluated: the first one, applying lightning overvoltage a...

Frequent Switching of arc furnace in steel company causes a great effect on the insulation of arc furnace transformer winding which in turn may causes a shutdown of production for long periods of time. Therefore, it is necessary to study and analyze the causes of these outages and design an adequate protective device. In this paper the transient overvoltage resulted from vacuum circuit breaker ...

During the switching on/off of shunt capacitor banks in substations, vacuum circuit breakers (VCBs) are required to switch off or to switch on the capacitive current. Therefore, the VCBs have to be operated under a harsh condition to ensure the reliability of the equipment. This study presents a complete comparison study of ordinary and phase-controlled VCBs on switching 10 kV shunt capacitor b...

Present-day small hydropower plants (SHPs) have a large development potential because of the increasing interest in renewable resources and distributed energy generation, therefore, there are many SHPs in places of China where are rich in water resources. However, it has caused overvoltages in the distribution network, and which is even worse for the switching overvoltage such as isolated netwo...

Gas-insulated substations (GIS) have different specifications in proportion to air-insulated substations. Transformer failures related to lightning and switching are often reported in the gas insulated substation (GIS). This problem is the voltage magnifications due to reflections of switching and lightning surges at various junctions within the GIS. thereby overvoltages in GIS are more importa...

this paper gives a detailed analysis of direct torque control (dtc) strategy in a five-level drive and proposes a 24-sector switching table. the overvoltage problem due to high dv/dt is reduced compared to the 12-sector dtc. using all vectors leads to better flexibility and reduces speed oscillations. simulation and experimental results for a 3kva prototype confirm the proposed solutions. a tms...

There are many reasons for over voltages in power system. The overvoltage causes number of effect in the power system. It may cause insulation failure of the equipments, malfunction of the equipments. Overvoltage can cause damage to components connected to the power supply and lead to insulation failure, damage to electronic components, heating, flashovers, etc. Over voltages occur in a system ...

Mitigating switching overvoltages (SOVs) and conducting well-suited insulation coordination for handling stresses are very important in UHV transmission Lines. The best strategy in the absence of arresters is controlled switching (CS). Although elaborate works on electromagnetic transients are considered in the process of designing transmission systems, such works are not prevalent in day-to-da...

Modern power converters frequently require snubberless operation of p-i-n diodes [1]. Due to the presence of fast-switching components, like last-generation GTOs and IGBTs, the diodes must be able to withstand, at turn-off, quick inductive switching, i.e., large, negative time derivatives of the diode current ((dID/dt)1<0) without large overvoltages, which requires a limited time derivative ((d...