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Voltage Balance of the series-connected dc-link capacitors is the key problem of three-level diode-clamped converters. In this paper, an auxiliary voltage balance circuit (VBC) is presented to maintain the voltage balance of dc-link capacitors. The voltage balance circuit consists of a clamping capacitor and a current-limiting inductor. With the clamping capacitor, the voltage stresses of the auxiliary...
The four-quadrant converters applied to the locomotive traction have higher requirements for the power density and reliability. Compared with conventional IGBTs, RC-IGBTs have the advantages of low thermal resistance and high current density. In this paper, RC-IGBT is applied to four-quadrant converter and the working characteristics and pulse distribution of four-quadrant converter under the desaturation...
This paper presents the systematic design and performance of two controls for half-bridge converters with LCL output filters based on a similarity transformation. This type of converters is commonly used in, for example, grid or battery interfaces. Both controls feature active damping, i.e. filter resonances are damped through software and not by using passive resistors. Moreover, both controls are...
This study presents a sensorless static model based with output current estimation method for digital PWM control dc-dc converters. The static model is a feedforward type control method adopted in coordination with the standard PID control and it can improve characteristics of wide input and output range of dc-dc converter by using information of output current. The one of the drawbacks of the static...
The emerging 650 V large current rating, Enhancement-mode (E-mode) Gallium Nitride High-Electron-Mobility Transistor (GaN HEMT) is a promising device for low to medium power, high power density converters (e.g., motor drives, battery chargers), which require high robustness levels. Thus, a comprehensive study of the short circuit behavior of high power E-mode GaN HEMT is the subject of this paper...
This paper presents an improved thermal equivalent circuit model which provides an accurate thermal and loss estimation for integrated power modules. Thermal analysis is a critical issue for power electronic systems, it estimates the thermal performance of power devices and enables a flexible converter design. Unlike the conventional thermal models, the modified analytical thermal model takes the...
Modular multilevel converters (MMCs) have become the most promising converter technologies for medium/high-power applications, specifically for high-voltage direct current (HVDC) transmission systems. For the analysis of the large-scale MMCs-embedded power systems, i.e., multiterminal dc (MTDC) systems and dc grids, modeling and simulation plays an important role in transient and fault analysis. However,...
The common-mode current casued by the parasitic parameters in the transformerless multilevel converters degrades the performance of converters and brings security issues. This paper presents a new zero common-mode voltage space vector modulation for common-mode voltage suppression in the five-level modular composited converter. Firstly, the common-mode equivalent circuit model of five-level modular...
This paper presents experimental validation of a high-fidelity toroid inductor modeling technique. The aim of this research is to accurately model the instantaneous magnetization state and core losses in ferromagnetic materials. Quasi-static hysteresis effects are captured using a Preisach model. Eddy currents are included by coupling the associated quasi-static Everett function to a simple finite...
The difficulty of modeling a resonant converter is the fact that, unlike a pulse-width-modulation (PWM) converter, an average concept doesn't work. The only successful equivalent circuit model, proposed by E. Yang, is based on fundamental approximation and harmonic balance theory. However, it is conceptually hard to understand because of an unidentified “equilibrium state.” A resonant converter was...
In this paper, the properties and performance evaluation of a novel ultra wide band gap device using Ga2O3 material is presented. Although Ga2O3 device is currently at its early development stage, the material and existing devices have shown tremendous potential in high power applications. The properties of Ga2O3 based on both theoretical limits and state-of-the-art prototypes for high power applications...
Soft-switching self-tuning H-bridge converters for inductive power transfer (IPT) systems with resonant current regulation are introduced. The proposed converters are controlled based on an amplitude modulation technique for resonant converters to regulate the transferred power in an IPT system. The switching operations of the converters are synchronized to the resonance current of the IPT system...
In this paper a design and simulation model of a brushless, self-excited field winding machine is presented. The rotor of this machine possesses two windings, a field winding and a “transformer” winding, that are connected through a diode rectifier circuit. Using field-oriented control techniques, an AC magnetic field is generated by the stator windings that is always aligned with the transformer...
This paper presents the design and experimental demonstration of a method for photovoltaic condition monitoring and hot-spot detection using a real-time adaptive parameter identification approach. The identification algorithm tracks parameters in an equivalent ac circuit model of a PV panel, and uses these parameter estimates to predict when the PV panel is partially shaded or in a hot-spot condition...
The advantages of the Modular Multilevel Converter (MMC) as a Voltage Source Converter (VSC) is well known. These includes scalability, increased reliability, lower Total Harmonic Distortion (THD) in output variables, fault tolerance and so forth. The MMC has found its most application in High Voltage DC (HVDC) systems again because of the stated advantages. In the analysis of such systems, because...
This paper investigates the influence of converter-fed operation on magnetic forces and radial vibration in a hydrogenerator. Flux density distribution is computed using time-stepping finite element (FE) analysis and used to calculate force density distribution based on Maxwell stress tensor. Both temporal and spatial characteristics of selected flux density and force density waves are studied. Important...
In order to estimate the accurate and real-time dynamic battery state of charge (SOC), owing to greater errors of extended Kalman filter (EKF) in estimating SOC, a method has been proposed to estimate the battery SOC based on LM-ICDKF algorithm. By using the two order RC equivalent circuit model, the MATLAB simulation tools are used to simulate the algorithm, this paper compares LM-ICDKF algorithm...
In designing a human-computer interface (interface for short) for a complex work domain, the first question to be answered is what information should be presented on an interface media. The simplest answer is: it depends on tasks to be performed by the human operator. In the past two decades, two methodologies have been developed with a purpose to answer this question, namely Abstraction Hierarchy...
Circuit Breakers (CB) are widely used protection devices in High Voltage (HV) AC circuit. This condition makes the CB as one the fundamental HV apparatus. This situation encourages HV apparatus manufacturers to produce CB in different kinds of voltage level with different capability and performance. In this research paper, we proposed a modeling method which can be used to select appropriate commercially...
As insulators play an important role in supporting power transmission and distribution system, ensuring their condition in order to keep working properly have become an unequivocally essential task to do. There are many ways that can be attained to monitor the state of insulators, which one of them is by observing the leakage current (LC) characteristics. Experiments of LC measurement on six field-aged...
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