Serwis Infona wykorzystuje pliki cookies (ciasteczka). Są to wartości tekstowe, zapamiętywane przez przeglądarkę na urządzeniu użytkownika. Nasz serwis ma dostęp do tych wartości oraz wykorzystuje je do zapamiętania danych dotyczących użytkownika, takich jak np. ustawienia (typu widok ekranu, wybór języka interfejsu), zapamiętanie zalogowania. Korzystanie z serwisu Infona oznacza zgodę na zapis informacji i ich wykorzystanie dla celów korzytania z serwisu. Więcej informacji można znaleźć w Polityce prywatności oraz Regulaminie serwisu. Zamknięcie tego okienka potwierdza zapoznanie się z informacją o plikach cookies, akceptację polityki prywatności i regulaminu oraz sposobu wykorzystywania plików cookies w serwisie. Możesz zmienić ustawienia obsługi cookies w swojej przeglądarce.
An effective approach, based on neural networks, to the fault diagnosis of dc-ac resonant inverters is presented. A MultiLayer MultiValued Neuron neural Network (MLMVNN) with a complex QR-decomposition is used to identify parameter value changing (i.e. fault detection) on a Class-E resonant inverter through steady state measurements of voltages and currents.
The paper presents fault tolerant control algorithms of modified space vector pulse width modulation (SVPWM) for three-phase inverter supplies a PMSM in case of failure of one transistor leg. Fault tolerant inverter structure with four-switch is analyzed with taking into account the non-ideal DC link. Calculations of the desired voltage vector in the PMSM drive are presented. An optimal voltage vector...
Transmission of power over long distances has become an important aspect in today's world because of offshore generations from wind, ocean currents, tidal, waves and others. In general, HVDC technology is well-accepted around the world. The VSC-HVDC has gained importance over the years. Certain problems regarding protection still remain, but with the implementation of the hybrid breaker, the system...
The development of dc transmission and distribution technologies are gaining traction. With renewable energy being fed to the grid constantly increasing, there is growing interest in development of dc grids. A major hindrance for their development is attributed to the lack of protection during short-circuit fault. Hybrid circuit breakers, a combination of mechanical and semi-conductor devices are...
Low Voltage DC (LVDC) distribution systems are new promising technologies which can potentially improve the efficiency and controllability of existing LV distribution networks. However, they do introduce new challenges under different fault conditions. Therefore, this paper investigates the performances of an active LVDC distribution network with local solar photovoltaics (PVs) and energy storages...
In the last years, the high penetration of renewable energy sources, especially wind power generation poses new challenges for the dynamic voltage stability analysis of an electric power system. The wind power plants are required to be able to satisfy the voltage control strategy and reactive power demands. The wind power plants should provide the reactive power exchange with the grid, due to the...
This paper describes a new algorithm for selection of faulty circuit in parallel series-compensated lines. It suits for protection of such lines and uses one-end phase currents measurements only. The developed method has been tested and evaluated using signals obtained from versatile computer simulations. A detailed models of considered transmission line including the SC&MOV banks as well as the...
In this paper, a method to limit fault current from DC side short-circuit condition in AC-DC power converters is presented. This approach is based on using Normally-ON SiC-JFETs in series with the DC capacitors as Current Limiting Diodes (CLDs). In this configuration, the gate and source contacts of the JFETs are connected together to make two-terminal devices (Vgs=0). Under a fault condition, the...
Modular multilevel converter (MMC) is one of the promising voltage source converter topologies in the field of high voltage direct current (HVDC) transmission system. Based on analysis of the existing sub-module topologies, an improved half-bridge sub-module topology based on reverse blocking IGBTs (RB-HBSM) was proposed for solving the fault ride through issues. In this paper, the fault current blocking...
A modular multilevel matrix converter (MMMxC) has nine arms and each of the arms is composed of H-bridge cells connected in cascade. It can be applied to high voltage ac-ac converters for variable speed wind turbines and motor drives. In this paper, employment of a hierarchical control system for the MMMxC is first considered to distribute computational burden among processors and simplify hardware...
This paper proposes a novel modular dual-active-bridge (DAB) dc-dc converter for spilt-battery energy storage system (BESS) in medium-voltage dc (MVDC) grid application. Compared to modular cascaded DAB converter, the proposed topology has current-fed DAB characteristics, with directly dc current control to achieve dc fault ride-through capability. In addition, the proposed converter exhibits favorite...
Modular Multilevel Converters (MMC) can provide significant advantages for power transmission applications, however there are remaining challenges trading off DC fault response, losses and controllability. Alternative multilevel converter topologies using combinations of full bridge and half bridge submodules or series switches allow for competitive efficiency whilst retaining control over the DC...
This paper proposes a thyristor based short circuit current injector for providing short circuit current in isolated and weak grids, where sufficient fault current to trigger circuit breakers may not be available. This will allow the use of conventional miniature circuit breakers, which requires high fault current for instantaneous tripping. The method has been validated through experiments.
The family of Modular Multilevel Converter (MMC) has become one of the most promising converter topologies for medium/high-voltage applications because of its modularity and scalability. Specifically, the AC-AC MMC is a promising candidate for medium-voltage motor drive applications. As the AC-AC MMC is based on stacking a large number of Submodules (SMs), its operation is vulnerable to SM failure...
A simple low-cost active EMI filter (AEF) without transformers is proposed. The equivalent circuit model of the proposed AEF is built, and a block diagram is extracted for efficient feedback analysis. The feedback loop gain and the performance of the AEF are calculated and validated by comparison with SPICE simulations. The proposed AEF enlarges the effective value of Y-capacitors. The AEF is manufactured...
Dual Active Bridge (DAB) converters are emerging to become the preferred high power DC-DC conversion topology to satisfy the requirements of modularity, high voltage transfer ratio, high efficiency and bidirectional power transfer capability. However transformer design for DAB converters remains a challenging problem, especially for high voltage conversion ratio and higher switching frequencies. Capacitor-coupled...
The Series-Resonant dc-dc converter (SRC) is widely used in several application and it became very popular in Smart Transformer application. In this application, fault tolerance is a highly desired feature and it is obtained through redundancy. This paper proposes a reconfiguration scheme for the SRC for the case of failure in one semiconductor, which could drastically reduce the need of redundancy...
Modular multilevel converter (MMC) has drawn tremendous attention in the academia and industry since its invention, and it is considered as a very suitable solution for the high-power applications. It is usually composited by a large number of half-bridge or full-bridge sub-modules (SMs), which makes the reliability as one of the most important challenges for MMC. Besides, due to the DC side short-circuit...
The Modular Multilevel Converter (MMC) is a promising technology for medium-high voltage DC/AC converters, being adequate for HVDC transmission systems. Among the appealing characteristics of the MMC are their modularity, and consequently their scalability, as well as the fact that there is no bulk storage element. One key aspect for the operation of the MMC is the response in the event of a short...
This paper deals with the fault tolerance analysis applied to the converter topology 5-level unidirectional T-Rectifier (5L T-RECT) to be used for electric generating applications. The proposed generating unit is intended for aerospace applications with high fundamental electric frequency, to this purpose the investigated power electronic converter configuration is able to supply power to the electric...
Podaj zakres dat dla filtrowania wyświetlonych wyników. Możesz podać datę początkową, końcową lub obie daty. Daty możesz wpisać ręcznie lub wybrać za pomocą kalendarza.