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...

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...

Induction motors are the most common means of converting electrical power to mechanical power in the industry. Induction machines were typically considered robust machines; however, this perception began to change toward the end of the last decade as low-cost motors became available on the market. Nowadays the most widely used induction motor in the industry is a machine which works at the limi...

This paper presents a time-sequential simulation technique incorporating the effects of interruptions and voltage sags in the reliability cost/worth evaluation of distribution systems equipped with different overvoltage protection types. The interruption and voltage sag data for different overvoltage protection schemes was obtained from long-term measurements performed at a 110/20 kV substation...

In this paper studies of overvoltage and capacitance measurements at silver cathodes in aqueous perchloric acid at room temperature are described. Capacitances were deduced from open-circuit potential decay measurements. The increase of overvoltage and the growth of the measured capacitances in the course of electrolysis are attributed to a growing pseudocapacitance component. This is anal...

Residential rooftop-mounted solar photovoltaic (PV) panels are being installed at an increasing rate, both in New Zealand and globally. There have been concerns over possible issues such as overvoltage and overcurrent. These PV systems are mostly connected at low voltage (LV). This study presents a case study of simulating the entire LV network from a single utility, comprising 10,558 11 kV–415...

The emergence of fast-switching wide-bandgap (GaN, SiC) power electronics devices has enabled motor drive systems to achieve high efficiency, density, control bandwidth and high-level integration. However, the speed switching frequency result in an increased level overvoltage at both terminals stator neutral. This increases stress across winding insulation bearings. paper investigates three typ...

With the application of the articulated phase insulator, and the speed of electric locomotive rising, it is inevitable for the electric locomotive to adopt the technology automatic passing through the electric phase separation. However, when the locomotive passes the electric phase separation, a variety of overvoltages will be generated, such as the cut-off overvoltage and the closing overvolta...

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 ...