High-speed EMUs (electric multiple-units) frequently pass through the phase-separation zone during operation. Overvoltage generated operation of vehicle-mounted circuit breaker has a long duration and high waveform steepness, which accelerates service life equipment is likely to cause insulation failures. For above-mentioned problems, operating overvoltage characteristics high-speed EMU were ob...

Abstract For suppress the amplitude of overvoltage from HVDC sending terminal, an suppression scheme based on principle controllable energy dissipation was proposed. The mechanism a weak AC system under fault DC analyzed, and method operating CSREDD were Prototype develop tested, which proved correctness about design. device has been successfully applied to ±800kV Lu-Gu UHVDC transmission proje...

This paper presents some implementation details of a threephase to three-phase matrix converter prototype. The bidirectional semiconductor switches were built using discrete IGBTs and fast diodes. Design aspects such as protection against overvoltage and short-circuit, commutation process Artigo submetido em 23/04/2010 (Id.: 1132) Revisado em 18/09/2010, 15/07/2011, 30/08/2011 Aceito sob recome...

The supply territory of the company E.ON Distribution in the Czech Republic (run by the company E.ON Czech Republic) accounts for approximately 1.5 million customers. More than 900MW of photovoltaic (PV) plants were connected to this distribution grid. It was detected the problem with overvoltage in approximately 20% low voltage distribution grids with connected PV plants and this problem has t...

Overvoltage is one of the issues in distribution grids with high penetration photovoltaics (PVs). Centralized or droop-based methods active power curtailment (APC) and/or reactive control PVs are viable solutions to prevent overvoltage. This article proposes two distributed PV inverters, which based on nodal sensitivities. Then, performance proposed compared commonly used methods, i.e., a metho...

Abstract In this work, the non-liner voltage distribution in transformer winding is investigated that occurs due switching and lightning. Transformer winding is modeled in the alternative transients program (ATP) version of Electromagnetic transients program (EMTPRV). EMTP software is used to simulate the very fast transient overvoltage. An experimental setup that consist of , Recurrent surge g...

This paper describes methodology for the computation of the electromagnetic transients in the high voltage substations, taking into account transients on the substation grounding system. Simulation technology is based on the system decomposition. Interconnections between different subsystems are done in each time step using Thevenin equivalents. Frequency dependent impedance of grounding conduc...