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The heating and cooling is very complex process for winding in large power transformer, which involves fluid dynamic, manufacture technology and numerical heat transfer and other related disciplines. Recently, the electromagnetic-Fluid-thermal coupled method and thermal network method are widely used by domestic and foreign researchers, whereas the oil flow distribution can not be taken into account...
Temperature rise is one of the main factors that affect the safe operation of electric vehicle. In order to improve the heat efficiency of the motor, the water-cooled motor of circular circumferential waterway for mini electric vehicle was studied as an object in this research, the structural parameters of the channel are optimized and analyzed from the following aspects: the width of the adjacent...
A new approach for the computation of electric fields is described, based on the response surface methodology(RSM) and geometric feature charge simulation method (GFCSM). And the novel combination of RSM and GFCSM is applied to calculate the electric field of the high voltage SF6 arc quenching chamber in this paper. The electric field distribution with higher calculation precision has been achieved...
Spray cooling is a new type of high heat flux heat transfer cooling technology. In the process, cooling medium is dispersed certain microscale droplets through the nozzles and injected to the stator core and winding. The spray characteristics will affect directly the heat transfer coefficient. So in the paper a test rig using a nozzle was constructed to explore the atomization characteristics of spray...
In this paper, an improved control strategy (ICS) based on the duty ratio modulation, by properly matching the positive voltage vectors with the new zero voltage vectors (ZVVs), is proposed in direct torque control (DTC) of brushless DC motor (BLDCM). The traditional voltage switching table for the six switches of the converter is modified according to this strategy to minimize the torque ripple....
The stable operation regions are the important issues for direct torque control (DTC) system of permanent magnet synchronous motor (PMSM). The influences of the parameters, such as voltage, current, flux linkage and load angle, on the system operation are investigated through the analysis model presented in this paper. The analysis results show that the parameters must be properly regulated within...
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...
For the vacuum arc, the parameters of the interelectrode plasma have influences on the electrode process. It is necessary to obtain the parameters and characteristics of the plasma by simulating the plasma among the electrodes. In this paper, based on the analysis of the existing vacuum arc model, combined with the characteristics of vacuum arc fault under different interrupting conditions, the effects...
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...
Industry applications in fields of electrical engineering have a high demandfor engineers with knowledge and experience in using digital signal processor(DSP). Many universities offer this type of training in DSP and motor control courses. However, in traditional teaching of motor control with DSP platform, it is difficult for the undergraduate students of electrical engineering to program the motor...
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...
To develop a new standard design of gas-insulated bus(GIB), an electromagnetic-structural finite element analysis has been conducted considering the electromagnetic force generated in GIB with a large current. The GIB are electrical bus-bar parts of a gas-insulated switchgear(GIS) installed as a protective device in power plants and substations. Since the electromagnetic forces generated by a large...
A FEM platform is developed to support high precision electric field computing and data analysis. For the precise computing of 550kV SF6 arc quenching chamber, a solve regions division project is presented to improve meshes quality and computation efficiency. At the same time, approach regular triangle algorithm is realized by combing the uniform and gradient disperse for boundary, constraint condition...
Core losses of nanocrystalline alloy high frequency transformer (HFT) are calculated by adopting the finite element method with magnetic hysteresis effects considered. A normal Preisach model is used to represent the magnetic hysteresis during the numerical simulation. The normal Preisach model features with simple formulations and easy parameters identification. A dynamic circuit model of laminated...
In order to improve the output performance, multi-stator structure is applied to traveling wave type ultrasonic motor (TWUM). In this paper, taking into account the multi-stator traveling wave type ultrasonic motor (MSUM) with diameter of 60mm, authors apply the elastic contact principle to deduce the MSUM's simulation model. By reason of machining errors and installation errors, the stators and rotors...
To calculate the fatigue life of shield ring following steps untaken: First, obtain the dynamic characteristics by using image recognition method and the finite element method. Second, calculate fatigue life cycle on the basis of the time-domain analysis results of vortex-induced resonance. Third, estimate the fatigue life of shield ring considering the probability of wind speed. Finally, design a...
Torque calculation using the d-q axis has the advantage of faster execution time; however, the torque ripple cannot be considered in torque calculation using the d-q axis equivalent circuit because the time-dependent component is removed. In this work, with d-q transformation, the characteristics of some parameters were identified. These characteristics were considered for representing torque ripple...
In this paper, a new double-sided linear flux-switching permanent magnet (DLFSPM) motor for electromagnetic launch system is proposed, in which the mover only consists of yokeless iron while the permanent magnets and armature windings are all located on the stator. Hence, this motor incorporates the merits of high thrust density of permanent magnet linear motor and high reliability of linear induction...
Accurate lithium-ion battery power capability prediction gives an indication for managing power flows in or out of batteries within the safe operating area, which is one of the primary challenging functions of battery management systems (BMSs). The battery direct current resistance (DCR) is typically employed for power capability prediction, but its characteristic depends significantly on the ambient...
A fractional-order analysis model of the chaotic oscillation in a 4D power system including synchronous generator exciter is presented in this paper. The dynamics of the system are investigated by using this model. Firstly, the minimum order for the occurrence of bifurcations was calculated from the invariant system parameter set. Then, the influence of the parameter variations on the dynamics of...
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