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In recent years, environmental problems are becoming serious and renewable energy systems, especially wind power generation, have attracted much attention and been introduced into power systems. However, wind power generator output is intermittent, resulting frequency fluctuations in the connected power system. A doubly fed induction generator (DFIG) based diesel generation system is proposed in this...
Electric model based in the duality between the electric and magnetic circuit taking into account the misalignment characteristic of transformer of a Wireless Power Transfer, WPT, is proposed. Being a model based in the constructive characteristic of the transformer the model, it represents better the misalignment effect and the simulation values are more accurate in comparison with the T model that...
This paper investigates the cross-coupling effect of a 3 degrees of freedom magnetic bearing (3-DOF MB) using the magnetic circuit method comprehensively. The EMF of X-axis (or Y-axis) coil induced by the current variation Eix (Eiy) can vary in a range of up to 14.7% due to the cross-coupling caused by Z-axis current. Moreover, the X-axis (or Y-axis) force characteristics and stiffnesses are significantly...
Linear induction motor (LIM) drive suffers heavily from low efficiency due to its large air-gap length, the end-effects, and the partial load working conditions. Therefore, an optimization method is proposed in this paper to improve the LIM drive operating efficiency from both design and control levels. First, the genetic algorithm (GA) is applied to design optimization of LIM to attain higher efficiency...
In order to improve the efficiency of high voltage power supply for electron beam welder, the characteristics of LCC series parallel resonant converter with capacitive filtering are studied in this paper, and the circuit model of LCC resonance in discontinuous current mode(DCM) is established. The working mode of the converter is analyzed by mathematical time domain analysis method, and the mathematical...
This paper discusses a single-phase inverter with a buck-boost converter for single-phase applications such as photovoltaic (PV) systems. The inverter consists of a buck-boost converter and an H-bridge unfolder circuit. The inverter requires only 1 controllable switch to obtain 100 Hz pulsating DC-link voltage. However, a conventional PV inverter requires two-stage power conversion. Thus, the power...
Phase-shifting reactor (PSR) can be used to solve the harmonic problems caused by rectifiers. In this paper, according to the active power balance principle, the relationships among DC current of load, currents of power supply side, as well as capacity of core limb are built, and the design specifications of winding and core are obtained. simulation of 6-phase rectifier system with PSR by the equivalent...
The short-time high capacity reactive power output and quick dynamic response performance are two key performances of new large synchronous condenser. In this paper, the effect of load condition on transient response capability of synchronous condenser by finite element analysis (FEa) model. A 300/-150Mvar prototype synchronous condenser is provided for modeling analysis at a group of different steady...
For evaluate the thermal behavior of a permanent magnet motor under different types of losses and various loss distributions, a simplified thermal circuit is proposed. The result shows that, the model presented in the companion paper is suitable to use in machine design with certain accuracy.
The paper presents a method of the series arc fault for DC systems. The aim of the study is to find some current characteristics, which can be significant for the purpose of arc detection. The validity of the proposed method is testified by analyzing the arc fault current signal. The low voltage series DC arc study is carried out on the currents waveforms acquired during some tests on electric appliances...
A three-dimensional finite element model of miniature circuit breaker is established. The steady state temperature field is obtained by the method of electrothermal coupling, and the mechanism of overload protection is analyzed. The influence of wire size on the temperature of bimetal is studied. A simple and effective method to reduce the influence of external wire size is presented. The influence...
The DC circuit breaker technology is one of the key technologies to build multi-terminal DC transmission network. Active DC vacuum circuit breaker (DCVCB) has become the research object. Based on the continuous transition model(CTM) and variable-step 4th-order Runge-Kutta method, sheath development stage during the post-arc dielectric recovery has been simulated and analyzed. Then the influence of...
There are many software can be carried out simulation of photovoltaic (PV) system such as PSIM and Matlab. Those software have their own advantages in the simulation of PV system. This paper proposed a joint-simulation of a stand-alone PV system based on PSIM and Matlab to achieve the maximum power point tracking (MPPT) of PV cells and the stability of PV system. In this paper, the main circuit is...
Stator inter-turn short circuit fault is one of the common faults in Double Fed Induction Generator (DFIG), the mathematical model of the DFIG is established based on the multi — loop theory, and the model of DFIG is built on the MATLAB / Simulink platform under normal condition and different degrees of inter — turn short circuit. The mathematical model of the grid side converter is analyzed to determine...
This paper presents a field-circuit coupled design and analysis method for the permanent magnet synchronous motor (PMSM) system used in electric vehicles. The time-stepping finite-element method is used to simulate the motor system, which integrates the electromagnetic field analysis of the motor prototype and the control algorithm of the drive system. A two-dimensional transient electromagnetic field...
The accuracy of PV array model directly affects the output characteristics of the PV system. In this paper, a simplified engineering model for PV array is established and the influence on the output characteristics of PV array is analyzed when Rs, Rsh and α, β, γ change. According to the actual data of a PV power station, the shuffled frog leaping algorithm (SFLA) is adopted to identify the parameters...
Single-phase capacitor induction motors are the most common low cost solutions for household appliance. An alternative high efficiency motor is the novel three-winding series-connected single-phase motor. This paper proposes the simulation and analysis of the fractional order model of the novel motor with full load and no load. A transfer function with a fractional derivative order has been selected...
In this paper, a three-dimensional (3-D) generic magnetic equivalent circuit (MEC) using mesh-based formulation was developed for the electrical engineering applications. The particularity of this model consists in a discretization with hexahedral mesh elements, which can be chosen by the designer. For example, the 3-D generic MEC has been applied to a U-cored static electromagnetic device. In order...
Transformer short-circuit force insufficient has been a hot research issue. There is some residual stress on the conductor section when winds the wounding, which produces adversely affect on winding short-circuit strength. This paper deduces the calculation model of the circular winding considering the residual stress. Taking the test transformer as an example, winding internal radiation short-circuit...
Nowadays, many studies on LVDC (Low Voltage Direct Current) distribution system are underway as the future solution for reliable power system network. This new concept in power distribution is expected to improve power system efficiency, reliability and uninterrupted power supply capability when it is implemented. This paper is based on Bipolar LVDC distribution system and it focuses on analysis of...
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