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Technology development has been promoted aiming for an environment-friendly traction power supply system for railways. Among other things, a stationary energy storage system using lithium ion batteries for hybrid cars has been put into practical use since 2007. This device temporarily stores regenerative power generated from an train when it is stopped and the power is able to be applied for energy...
This paper presents a new circular shaft motor (CSM) model for development of haptic forceps system which has multi-degrees-of-freedom (MDOF). The prototype of CSM has issues; it is difficult to construct the stator as designed and the thrust characteristics is not enough high. The proposed CSM model includes trapezoidal magnets which are magnetized in axial direction. This structure can facilitate...
An integrated single-phase single-stage high-frequency (HF) isolated dual-tank LCL-type series resonant ac-dc converter with fixed frequency, phase-shift control strategy is presented. The circuit configuration combines a diode rectifier, boost converter and two identical half-bridge dc-dc LCL resonant converters. A high power factor (PF) and low total harmonic distortion (THD) is achieved by discontinuous...
The vibration suppression on a resonant system, based on the reflected wave rejection, has been recently proposed. In the method, the resonant system is modeled through a wave equation, in order to consider high order vibrations and vibration suppression is achieved by eliminating a reflected wave from the resonant system. However, it is impossible to implement such method when there are input and...
Self-decoupled dual pick-up coils for roadway powered electric vehicle (RPEV) with large lateral tolerance and low EMF for pedestrians are proposed. The accurate equivalent circuits and mathematical models for the dual pick-up coils are completely developed to decouple the two adjacent pick-up coils for the both cases with and without core plates. The proposed models are verified by simulations and...
This paper presents a simplified qualitative comparison of previously presented cascaded multilevel converter topologies for ac-ac conversion with particular emphasis on motor drive applications. Performance criteria such as the pulsation of the stored energy in the cell capacitors and the total required semiconductor rating are derived by analytical methods. The main conclusion is that the back-to-back...
This paper proposes a new power flow controller consisting of six multilevel cascaded converters for stabilizing and regulating the line voltages in distribution networks. Each cascaded converter is composed of series connection of H-bridge converters, and connected between one phase in the sending end and the other phase in receiving end. While each cascaded converter control only reactive power...
In this paper, some application examples of energy saving measures in two representative Japanese railway companies, mainly in d.c. electric traction power supply system, are introduced. The effect of electric energy storage systems installed to substations is mentioned especially. In addition, it is also described about the potential of regenerative braking energy, which will be able to be utilized...
The feed-forward charge/discharge control scheme of energy storage systems (ESS's) for DC electric railways takes advantage of the fact that the track and speed profiles are already available for all runs of trains before they take place. Using the track and speed profile information, the capacity of the ESS's can be best utilised to obtain maximal effects. This idea can be used for both onboard and...
Effective use of regenerative brake is important to manage energy-saving. This paper presents a running method for energy-saving on DC-electric railways considering restriction of keeping running time. First, two methods are compared for an energy-saving operation. One is applying a low notch-off speed with a strong brake. The other one is applying a fully regenerative brake with an ordinary notch-off...
In AC/DC converters for on-board chargers, the DC-link capacitor on the output side in a power factor correction (PFC) converter uses aluminum electrolytic capacitors in order to obtain a large capacitance with low voltage ripple and small size. Therefore, it is necessary to reduce the capacitance when using film capacitors without increasing the size of the converter in order to realize a capacitor...
A bi-directional isolated DC/DC converter for medium-voltage applications have been discussed for the next-generation electrical grid, such as smart girds. To realize the DC/DC converter for installing on a power distribution system, it should be achieved higher-efficiency and lower-volume. Higher switching frequency enables to reduce the volume of the transformer. However, it is difficult to realize...
Different converters such as the traction inverter and DC/DC converter are connected to the dc bus of an electric or hybrid electric vehicle. Harmonic models of these devices towards the dc bus are needed to investigate different phenomena like the dc bus transients and ripples. A high-frequency harmonic model of a traction circuit, a drive system based on a three-phase inverter connected to an ac...
This study proposes a novel 5-level converter topology in which common flying capacitors (FCs) are shared by three phases. This circuit can output voltage patterns prohibited in the circuits of the previous study. Furthermore,a back-to-back (BTB) configuration can be realized by only increasing the number of the phase units of the 5-level converter. This BTB system employs common FCs for all input...
A mathematical model is proposed for the high-efficiency control law of a permanent-magnet synchronous motor (PMSM) in the stator flux linkage synchronous frame (M-T frame). The mathematical model takes into consideration magnetic saturation and cross-magnetization effects. In taking into consideration magnetic saturation effects, most of the mathematical models in the d-q frame are complex. The M-T...
A hybrid power system placed in Beaufort Sea in order to power supply the offshore oil and gas platforms is investigated in this paper. The proposed microgrid includes various energy sources such as photovoltaic panels, wind turbines, diesel generator as a secondary power source and stationary storage system. Simulation of each component and the proposed topology is discussed with the energy management...
The PRM which uses reluctance torque positively and reduced the amount of magnets relatively, and the industrial low-voltage inverter to which the PRM control function is applied has been developed. Though exact motor parameters may not be known, the inverter has a control method which on-site PMM control commissioning can be performed easily for such the case. The combination test of the PRM and...
This paper examines the control performance of a permanent magnet synchronous motor drive system based on direct torque control (DTC) using a SiC-MOSFET inverter (SiC inverter). The dead-time of the inverter affects the performance of the motor control. In high-speed drives, the dead-time effect increases because the control period becomes shorter. By using a SiC inverter for which the switching speed...
This paper proposes fast initial position estimation of IPMSMs (Interior Permanent Magnet Synchronous Motors), which is based on intentional pulse voltage injection and comb filters. Most initial position estimation methods utilize the amplitude or differential values of high-frequency currents and the performance of sensorless control depends on the algorithm to reconstruct these values. Although...
In this paper, we would like to review and introduce technologies which mitigate problems in an electric power grid caused by installation of renewable energy sources (RES). We classified these technologies into three types of technologies in an analogy of “medical therapy” categorization, which are “causal therapy”, “symptomatic therapy”, and “infection prevention”. As for the causal therapies, active-power-based...
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