Search for: post-fault-operation
0.006 seconds

    Post Fault Vector Control of CHB Driven Induction Motor

    , M.Sc. Thesis Sharif University of Technology Fathi, Manochehr (Author) ; Zolghadri, Mohammad Reza (Supervisor)
    Multilevel converters are considered recently as one of the industrial solutions for high-power and power quality demanding applications. Casacade H-Bridge (CHB) converter is one of the well known topologies among multilevel converters. CHB converter is characterized by its high modularity allowing its power to be easily increased. Modularity also allows any faulty cell to be isolated, so the load can be fed by the remaining operative cells, which leads to an unbalanced output voltage of the CHB converter. To avoid the unbalanced operation, recently a solution based on modifying the phase and the magnitude of the voltage refereces has been proposed. This thesis presents a method to control... 

    Fast Failure Detection in Modular Multilevel Converter Power Switches for Fault Tolerant Operation

    , Ph.D. Dissertation Sharif University of Technology Haghnazari, Saeed (Author) ; Zolghadri, Mohammad Reza (Supervisor)
    Multilevel converters are the best solution in medium and high voltage applications because of their better output votage quality, redundant structure, less power semiconductor losses and common-mode voltages. Modular multilevel converters (MMCs) have additional advantages such as higher degree of modularity, transformerless operation capability and using a single common DC-bus. All these useful features make MMC the first alternative for HVDC systems. Fault detection, defected cells insulation and post fault operation control are necessary to ensure MMC continouse service. A simple, fast and accurate fault detection method is proposed for MMC semiconductor power switches in this thesis.... 

    Fault-Tolerant Operation of Three-Phase Dual Active Bridge Converter Against Semiconductor Power Switches Fault

    , M.Sc. Thesis Sharif University of Technology Davoodi Moghadam, Amirali (Author) ; Zolghadri, Mohammad Reza (Supervisor)
    The three-phase Dual Active Bridge DC-DC converter, by virtue of its various advantages, has been widely used in numerous industrial and sensitive applications. However, this converter includes a large number of power switching devices, which are the most fragile components in Power Electronics, and therefore, can pose a threat to appropriateness of the converter for such applications. Accordingly, introducing a fault-tolerant scheme for this converter is necessary, in order to meet the demands of high reliability and service continuity in aforementioned applications. In this thesis, firstly, the converter is studied during normal operation as well as under switch open-circuit fault, and the...