The compound catenary equipment on the Shinkansen lines currently requires large-scale renewal. To streamline this process and reduce maintenance costs, an efficient strategy is to replace the compound catenary equipment with simple catenary equipment rather than renewing the compound catenary equipment. However, simple catenary equipment, unlike compound catenary equipment, induces large vertical oscillations of the pantograph between support points. When thick wires are used to ensure the current capacity, the fluctuations in the contact force between the contact wire and the pantograph tend to be large because of the hanger intervals. In this study, a new type of Shinkansen simple catenary equipment was developed for operating speeds of 320km/h, which is the current maximum speed on commercial Shinkansen lines. Theoretical analyses and dynamic characteristic evaluations were conducted to validate the performance of the developed catenary equipment. A field test on a commercial line further verified the current collection performance of the developed catenary equipment.

In this paper, we present a design methodology for determining the resonant tank frequency in a feedback control-free dynamic wireless power transfer (DWPT) system for an automatic guided vehicle (AGV). High stability in power transmission characteristics against misalignment between the power transmitting and receiving coils can be achieved by setting a coupling coefficient-independent frequency as the optimum one. The principle of resonant tank frequency determination is originally proposed on the basis of steady-state analysis. The practical effectiveness is verified using a 1.5kW-85kHz DWPT prototype.

In hot metal rolling mill system, achievement of strip width accuracy is important issue. However, temperature fluctuation caused by skid-marks in a furnace deteriorates the strip width quality. System identification is a statistical method to build mathematical models of dynamic systems from measured input-output data, and it is expected to be one of the most useful methods of modeling for big data. By using system identification, the dynamics of width fluctuation in bar was predicted on-line, and it is compensated for by model predictive control. As a result, the accuracy of width control is successfully improved.

In this study, we aimed to reduce the AC battery current in dual-source electrical trains powered by batteries and AC catenary using an auxiliary converter along with a small DC inductor connected in series with the batteries. The auxiliary converter is equivalent to a conventional single-phase converter, and it works to reduce the 120-Hz AC current according to the operating modes of the train. The operating principles and control methods of the proposed system, including the detailed current analysis, were experimentally validated using a 1.3kW downscaled model.

Wireless power transfer system used in Superconducting Maglev employs power control based on the envelopes of root mean square (RMS) values. The control aims to stabilize the power supply between the ground and on-board systems. To evaluate stability under various conditions, mathematical models are required. In particular, representing approximate RMS envelope with a transfer function is challenging. This paper we propose a simplified method to derive a transfer function with complex coefficients and certain modifications. As a result, the calculated transient response of the circuit to a step voltage input closely matches the measured response. Additionally, stability criteria based on the complex coefficient transfer function are introduced.

Analytical models of interior permanent magnet synchronous motors (IPMSMs) use dq-axis equivalent circuits. Accurate prediction of IPMSM performance requires a) mathematical modeling of the circuits used to implement different electromagnetic phenomena inside the motor and b) accurate estimation of the equivalent circuit parameters. Therefore, accurately calculating the magnitude of the dq-axis flux linkages from experimental data is essential; however, the influence of iron loss on flux linkage calculation has not been reported yet.

In this study, the effect of iron loss on flux linkage calculation, —specifically, the increase in armature voltage that includes a component for iron loss—, was experimentally clarified using a prototype IPMSM. We propose a novel dq-axis equivalent circuit model based on these results. In the proposed model, no-load and negative d-axis current iron losses are represented by an iron loss resistance connected in parallel with the q-axis equivalent circuit. In addition, the iron loss caused by the q-axis current is represented by an iron loss resistance inserted in series in the d-axis and q-axis equivalent circuits. The accuracy of torque calculation based on the proposed model was experimentally verified using a 7.5kW IPMSM prototype.