The Circuit Analysis and Performance Evaluation of an Hc Type Magnetic Coupling Contactless Power Transformer that is Compatible with Both Solenoid and Circular Type Transformers

There are two types of the transformers in a contactless power transfer system: solenoid type (H‐shaped) and circular type transformers. These two types of transformers are not compatible because their magnetic field structures are different. An Hc type transformer that is compatible with both transformer types has been proposed. The Hc type receiver adds a central magnetic pole by dividing the winding coil of the H‐shaped receiver. The Hc type receiver can change the magnetic field structure by changing the connections of the divided windings and can receive power from both types of transmitters. In this study, we conducted a circuit analysis and evaluated the performance of the Hc type transformer.     

A High Immersive Telexistence System of the Moving Object with Full Circumference Image and Inertial Force Presentation

Currently, the remote control such as the bilateral control which enables transmitting the multimodal information has been studied. However, remote control has not been reached while perceiving the wind, gravity, and the condition of the ground on the moving object at the remote place. When it is possible to perceive the external force applied to the moving object, it is possible to perform an appropriate operation sensuously according to a remote place such as a slope or a gravel road. Therefore, we propose a high immersive telexistence system with head mounted display and the six‐axis motion base which enables transmitting the inertia and force information of the moving vehicle, and 360‐degree image of moving object's surroundings at real‐time.     

Scaling Law of Coupling Coefficient and Coil Size in Wireless Power Transfer Design via Magnetic Coupling

Wireless Power Transfer (WPT), such as magnetic resonant coupling using a magnetic field, is being studied and discussed for a wide variety of applications. When the transmission distances are large, very large transmitters and receivers need to be considered. However, in the early stages of an investigation, it might be prohibitive to manufacture and evaluate coils of such a large size. To reduce costs and effort, a scaling law can be used to estimate the WPT efficiency of very large coils using the results of smaller coils. In this paper, a scaling law is proposed that relates the coil size to the coupling coefficient, assuming the ratio between the coil diameter and coil length remains constant. The coupling coefficient is one of the parameters that determine the maximum efficiency of magnetic field WPT. The proposed method was verified by an electromagnetic field simulator and experiment. The results of this study provide an easy method for estimating the WPT efficiency of very large coils.     

A Power Control Method to Save Energy for Wayside Energy Storage Systems in dc‐Electrified Railway System

The introduction of wayside energy storage systems is effective for the recovery of regenerative brake energy in dc‐electrified railways. However, considering the cost of their deployment, it is preferable to maximize the energy saving effect with a minimum capacity of the energy storage devices (ESDs). In this paper, we propose a power control method that can improve the energy saving effect while managing the energy of the ESDs. The proposed method is implemented by controlling the filter capacitor voltage of the line side of the power converter for the ESDs depending on their energy and the line voltage of the overhead contact line to which they are connected. Next, the proposed method is verified by numerical simulations and experimental tests with a 1 kW class downsized model.     

Jib crane control to suppress load swing

The simulation of a jib crane control strategy is reported which transfers a load under the condition of suppressing the load swing both in the transfer process and at the objective position, making the transfer time as short as possible. A non-linear dynamic equation of the load in a jib crane motion is derived. By linearizing the equation and giving a cost function of the second order, the control problem becomes LQ-type with control constraint u. Computer simulations show that this control strategy is able to suppress the load swing by the extending or shrinking motion of the boom.     

Construction of the Seismic‐Analysis Technology of the Insulator Base Metals in a Single Pole Structure Disconnecting Switch

In the disconnecting switch of 300 kV or less single pole structure, the Great East Japan Earthquake received much damage at the former by the rotation insulator base metal which damage experience had. Conventionally, we carried out a simple desk evaluation about earthquake‐proof evaluation of insulator base metal. However, there is deviation with the damage actual condition and it became clear that it was an apparatus weak point part. Then, we worked on the analysis accuracy improvement of insulator base metal, and we built the analysis technology of the single pole structured disconnecting switch.     

An analysis of land use/cover change in Indonesia

The phenomena of land use/ change were evaluated by using a remote sensing approach in a case study in Yogyakarta, Indonesia. The index of changes, which was calculated by the superimposition of land use/ images of 1972, 1984, and land use maps of 1990, were introduced to analyse the pattern of change in the area. The results demonstrated that the pattern of land use/ change in the study area was that of paddy coverage to open/ land to settlement. The annual growth ratios of new settlements to absorb paddy coverage, mixed vegetation, and open/ land were 16 per cent, 20 per cent, and 64 per cent respectively. The larger the percentage of the paddy coverage, the higher the tendency for settlement growth to absorb the paddy coverage, and the larger the percentage of open/ land, the higher the tendency for settlement growth to absorb open/ land. Settlement growth had a high correlation with road accessibility. The highest settlement growth was distributed mostly in suburban areas between 200 and 400 m from secondary roads. Without intelligent intervention by the government and public awareness, the loss of these agricultural land cannot be stopped and will jeopardize the local and regional economy.