On September 11, 2010, the Quasi-Zenith Satellite (QZS) “Michibiki” was launched from the Tanegashima island as the first satellite for positioning in Japan. We have attempted to fix positions using LEX data with CMAS (cm-class Augmentation Service) for cm level positioning augmentation signal via Michibiki.

The authors tried to fix positions by using LEX data at a stationary point and in a moving car in real time and with post processing. They could confirm no more than 2.22cm as the average positioning error and discrepancy of post positioning.

In this study, an Indoor MEssaging System (IMES) was used to determine walking positions in an indoor situation at rates of 50 and 250bps, transmitting powers of -65 and -85dBm, set heights of 1.63 and 2.67m, and one, two, or four receiver channels. The results confirm that the best tracking of pedestrians in an indoor situation is achieved using IMES with a transmitting power of -65dBm, set height of 2.67m, rate of 250bps, and four receiver channels. The results of these experiments will be of use for new IMES/GNSS chip set designs.

Electrostatics is used in electronic equipment and becomes occasionally a source of a malfunction or failure of the equipment. When a charged body such as a charged human body moves near ungrounded metal boxes of electronic equipment, the induced voltages of the metal boxes are changed. In this study, the induced voltages generated on two ungrounded metal boxes are experimentally measured. The results show that the values of the induced voltages of the two metal boxes are -2.2 times that of a moving charged body. The electrostatic energies for the distance D of more than 50cm between the two metal boxes are less than 50% of the energies for the distance D of 1cm. The mode of the induced voltages changes as the distance D between the two metal boxes increases. The results will be useful in considering an arrangement of the electronic equipment and the preventive measures for the electronic equipment.

The discrimination of a human body using electrostatic induction is important from the view point of the protection of personal privacy without the use of a surveillance camera, etc. Discrimination using a surveillance camera is not desirable to protect personal privacy though the camera is used frequently. The discrimination of the height and posture of a walking charged human body has not been performed though there are some related studies on electrostatic induction. In this study, we use an induction ceiling and induction flooring for discriminating the height and posture of a charged human body. The tests of the human body discrimination are performed when the subject is marching in place on the induction flooring. The experimental results show that the percentage of the induced voltage generated on the induction ceiling to the charged human body voltage decreases when the height of the charged human body decreases. The experimental results are compared with the results of a capacitance model that consists of capacitances between bodies obtained from the measured grounding capacitance. The calculated results show a similar trend to that of the experimental results. The results will be helpful to discriminate the height and posture of a walking charged human body.

Fast Automated Demand Response (FastADR), which controls the power consumption of customers' loads, is one of the future smart grid technologies. In this paper, a neural network modeling of the FastADR response property for the power consumption of building air-conditioners is studied. We propose an efficient training data collection method with operation condition zoning using the FastADR-like signal modulation during normal air-conditioning operation.

In recent years, the method of insulating electrical circuits using ground relays has been used for ground-fault current detection in power facilities, ; however, we cannot identify the causes of the ground-fault. In this study, by focusing on the eight major causes of ground-fault, namely “Tree contact”, “Insulator crack”, “Surface pollution”, “Rain”, “VS insulator deterioration”, “Induced thunder”, “VT breakage” and “Power cable”, we evaluate the cause by using the new decision method. The results of this study show that the decision method proposed in this study can identify the cause of ground-fault with high accuracy via decision tree analysis, and that it is possible to construct a sophisticated energy supply and demand system.

In order to spread automatic power factor controllers (APFCs), we developed a `Smart APFC' which is simpler than conventional APFCs. We studied the effects of installing timers, conventional APFCs, and Smart APFCs to the connections of high voltage consumers, such as reduced electrical losses, decrease in the rise of voltage, and lower harmonic voltage in distribution lines. In this paper, we present a scheme for introducing APFC to demand equipment.

The In-Wheel Motor (IWM), which is a driving system for Electric Vehicles (EVs) is effective for improving driving range or reducing vehicle weight. However, IWM has not been put to practical use because of a possibility of power line disconnection. Therefore, we proposed a Wireless In-Wheel Motor (W-IWM), in which Wireless Power Transfer (WPT) is used to remove these lines and improve the practicability of IWM. In this paper, the advanced system of W-IWM, which has a Supercapacitor (SC) and circuit for dynamic charging on its wheel side, is proposed. Additionally, a power-flow control method is proposed to control the power-flow of multiple power sources in the system. The power-flow control method is verified by simulation and experiment.

This paper proposes a converter control method for the system interconnection of an electric vehicle power conditioning system (EVPCS). The proposed system applies cooperative control of the DC link voltage and system power control capable of suppressing the reverse power flow to enable seamless charge and discharge of the EVPCS. The results of both the simulation and experimental verification using an actual equipment demonstrated that the proposed system successfully suppressed the reverse power flow and follow up on the power commands while the EVPCS did not stop due to sudden changes in the load power or significant changes in solar power generation in the photovoltaics.

This paper proposed a space vector modulation method to reduce the input current harmonics of a matrix converter. In the proposed method, the input current harmonics were defined in order to evaluate the input current THD of each modulation rate, power factor and phase of the input and output. Switching patterns minimizing the input current harmonics and distribution of the input current harmonics were shown by visualizing in the space vector. The proposed space vector modulation method clarified the effectiveness of the input current harmonics reduction by simulations and showed the 40-point reduction of the input current THD as compared with the conventional method.

This paper presents a novel detection device for deteriorated zinc-oxide (ZnO) surge arresters. It is necessary to understand the state of ZnO surge arresters for AC traction substations under operation. The waveform distortion of leakage currents can be detected through an increase in multiple harmonic currents; therefore, this effect was employed to develop a device for diagnosing damage to the surge arrester. By adopting a Rogowski coil and band-pass filters, we can obtain more output of the 5th-15th order harmonic currents in comparison with conventional devices. If the threshold value of harmonic elements is exceeded, the lights on the device may light up to indicate the deterioration. The validity of the device was verified by artificial deterioration tests using damaged ZnO elements and a capacitor. This developed device could indicate the soundness of the surge arresters that are in proper working order while being under the influence of feeding voltages, which include harmonic voltages.

A Z-source inverter (ZSI) can achieve boost and inverter function in single stage without a boost converter by using a short-through mode which shorts legs of the inverter. And it can be more high power density by employing a SiC-MOSFET which can drive high frequency operation. When employing the SiC-MOSFET for a conventional inverter, the SiC-MOSFET needs an additional SiC-SBD connected in parallel to avoid body-diode conduction in dead-time. This SiC-SBD becomes disadvantage for size reduction of the circuit, however conducting the body-diode is cause of degradation of the SiC-MOSFET and decreases reliability of the circuit. Thus, to remove the SiC-SBD from the the conventional inverter is difficult. This paper proposes to eliminate the body-diode conduction in the SiC-MOSFET on the Z-source inverter by using short-through operation without an additional SiC-SBD. From experimental investigation using a quasi-Z-source inverter which is one of the Z-source topology, it was confirmed that a current does not flow into the SiC-MOSFET body-diode by using the proposed space vector modulation including the short-through operation. This result shows that the Z-source inverter can take full advantage of the SiC-MOSFET.

This paper describes the high efficiency capability of multi-phase inverter-fed permanent magnet synchronous motors. In this type of motor, each armature winding is connected with an independent H-bridge inverter. The type of construction achieves a wide range of operation and high efficiency driving. Firstly, it is confirmed that the motor can expand the operating range by using winding reconfiguration. The inverter configurations are capable of changing their connections to different coil groups in the armature winding. To achieve high efficiency driving, a large torque production method and iron loss suppression method are proposed. With the proposed method of construction of the motor drive, the flux waveform in each stator tooth can observe and control in spite of the full-pitch distributed winding. The combination of controllable flux and arbitrary current excitation can generate a large output torque and reduce the iron loss. The simulation and experimental results show that the proposed method can significantly reduce the total loss.

This paper presents a high-voltage hybrid dc circuit breaker that produces no conducting power loss during normal operating conditions and that has the capability to interrupt a large amount of short-circuit current within several milliseconds. It consists of a current-limiting inductor, a current-control inductor, the following two mechanical switches; a low-voltage quasi circuit breaker (LV-qCB) and a high-speed disconnecting switch (HS-DS), and an advanced multilevel converter based on the cascade connection of multiple single-phase bridge cells. This hybrid dc circuit breaker is characterized by achieving current commutation from the LV-qCB to the multilevel converter capable of fast current control. This circuit configuration makes it possible to eliminate power switching devices from the main current path. This elimination leads to producing no conducting power loss during normal operating conditions. This paper provides a theoretical and experimental discussion on the operation, control, and performance of the hybrid dc circuit breaker. It includes verification through a downscaled experimental system rated at 300 Vdc and 150Adc, as well as confirmation through circuit simulation using the “PSCAD” software package.