There is a lot of potential to install photovoltaic panels along railroad tracks, and some systems have been already realized. When large-scale PV is introduced in several places, we should consider an efficient system for voltage control. To control voltage effectively, we studied two methods. One method is to control the sending voltage by LRT and another method is to control reactive power cooperatively by more than two PCSs in actual models along railroad tracks. The results showed that both methods could increase the generated electric energy by about 50MWh/year.
In this paper, we propose the structure of a high-power inductor with high heat dissipation using a spiral type edgewise coil for high-frequency applications. The proposed inductor shows characteristics that suppress the increase of copper loss with the skin and proximity effect and parasitic capacitances. Furthermore, we report that the heat dissipation of the proposed inductor is improved by providing a heat transfer structure inside the rectangular wire.
This paper describes the influence of rotor eccentricity on the vibration characteristics of a concentrated winding interior permanent magnet synchronous motor (IPMSM) by using a finite element method (FEM) and several measurements. The rotor eccentricity primarily caused an increase in radial electromagnetic force. In addition, an IPMSM with rotor eccentricity has higher vibration acceleration than an IPMSM without rotor eccentricity.
In this study, an equivalent circuit model of electric double-layer capacitors (EDLCs) reflecting a branched-pore structure for activated carbon was developed. Geometrical parameters such as pore diameter, pore depth, and branch number of the macro pore, meso pore, and micro pore were estimated from the analysis of the electrochemical impedance for EDLCs, combining theoretical equations and an equivalent circuit model. The developed equivalent circuit model was applied to charge/discharge simulations of EDLCs. The experimental and simulated cell voltages during pulsed-current charge were found to be in excellent agreement. Distributions of currents and voltages in the macro pore, meso pore, and micro pore during pulsed-current charges were discussed using equivalent circuit simulations. Electric-double layers were charged in order of the macro pore, the meso pore, and the micro pore. It was suggested that charge delays of the meso pore and the micro pore originated from both solution resistances in pores and the branch structure of the pore for activated carbon.
This paper proposes a new configuration of a pulse voltage generator, which can be applied to the klystron modulator for a large-scale accelerator. The voltage generator consists of a conventional capacitor discharge type pulse voltage generator and series cascaded voltage compensators. By using the voltage compensators, higher voltage fluctuation of the bank capacitor is acceptable; therefore, its capacitance and the dimensions of the capacitors can be low. This paper discusses the control strategy of the voltage compensators and thyristors for DC voltage supply for the highly fluctuating capacitor voltage, and demonstrates this by a laboratory-scale experimental setup.
Historical train traffic records are useful for identifying the cause of delays and to trace the propagation of delays. However, because the volume of the records is huge, visualization algorithms are necessary. In this paper, we introduce three methods; namely a chromatic diagram, a delay diagram and a 3D diagram. Then we show the results of evaluation by professionals who are engaged in timetabling.
We have studied the electrical treeing generated in silicone gel used as an encapsulant for power electronics modules. The treeing which consist of bubbles and strings was named Pearl-chain-type treeing. Under AC voltage application, the bubble vibrated with repeating expansion and shrinkage. We have obtained new insight that the expansion of the bubble at polarity inversion was very important for the development of the tree.