The Kyoto Protocol entered into force in February 2005 and became binding as international law. As the most efficient, economical and environmentally-friendly means of mass transportation, railroads will continue to develop, but will be subject to increasing requirements in the future for smaller size, lighter weight, energy savings, less maintenance, quieter operation, and increased comfort for the elderly. To meet the environmental standards for roadways, technology to reduce the concentration of nitrogen dioxide is required. Fuji Electric intends to collectively address the needs of these fields and to continue to make positive contributions by developing new technology for transportation systems.

Since the start of the Tokaido Shinkansen in 1964, the propulsion systems for Shinkansen trains have realized technical innovation while responding to requests for greater stability, reliability, economical efficiency, and to subsequent requests for higher speed, energy savings, and the support of environmental-related issues. Such technical advances are greatly indebted to the remarkable breakthroughs in power electronics technology, which include higher voltage and larger capacity power devices for the propulsion system that controls the main motors, and the higher performance and high speed of microprocessors. This paper describes the technical changes that have occurred in Shinkansen propulsion systems, and the present status and future trends of electronic products for the propulsion system of the latest Shinkansen, the Series N700.

Fuji Electric manufactures high value-added equipment incorporating instantaneous control for each phase and a high performance oneboard controller that have been developed to satisfy the increasingly sophisticated requirements for auxiliary power supply equipment in an electrical multiple unit. For the 3.3 kV high-voltage IGBT, the mainstream device at present, the generated loss is large and the carrier frequency cannot be increased to a high frequency, and thus there are limitations in the degree to which the filter reactor can be made smaller and lighter and the noise reduced. This paper describes voltagebalancing technology for IGBTs connected in series that was developed to overcome the above challenges and to achieve even higher valueadded performance.

Fuji Electric has developed and delivered a normally-conductive magnetic levitation system for Linimo, which was put into practical service as the main access to the Expo Aichi 2005 as Japan's first magnetically levitated train. Fuji's newly developed magnetic levitation system adopts several novel control technologies in order to achieve stable levitation and comfortable ride quality, while the attracting magnet type levitation control system is inherently unstable. Various measures have been adopted to ensure the reliability of the levitation system which is key to Linimo.

The side door systems of a train car must be safe and reliable with high performance requiring least maintenance because of the following reasons: the systems have direct contact with train passengers, each system is independently operated, and a number of systems are installed on a train. Fuji Electric has developed and commercialized the door operating systems that apply the linear motion of the linear motor to the linear movement of a side door. These systems have been delivered to the East Japan Railway Company and to the Metropolitan Transportation Authority New York City Transit. This paper describes the history of development and presents an overview of the system.

Power electronics equipment is increasingly being applied to electric railway ground systems. This paper describes the self-commutated Static Var Compensator (Self-commutated SVC) to compensate for unbalanced loads at Shinkansen Railway substation and PWM converters adopted at Tsukuba-Express DC feeding system, and also discusses technical details of theses applications and their effectiveness based on onsite data measurements. The application of power electronics technology to railway ground systems will further accelerate the trends toward smaller size, higher functionality and higher performance of those systems.

Fuji Electric has developed a line of various products, which in addition to protecting the global environment, also aim to realize the requirements of railway electric power systems of low lifecycle cost, lowmaintenance, small size and light weight. This paper introduces the following state-of-the-art products used in DC traction power systems: a 24 kV dry-air insulated switchgear, a water vaporization-cooling silicon rectifier and regenerative power inverter, a 100 kA DC high-speed vacuum circuit breaker, and a unit-type control switchgear.

A train radio system is a secure communications system linking a railway traffic control room with attendants on a train. Previously, such systems were implemented with voice communications only, but in response to customer needs for improved operational efficiency and a wider range of passenger assistance services, data transmission and other advanced technologies have been considered. This paper discusses the technology for realizing advanced train radio functions, and presents an overview of central systems and onboard radio equipment in the communications environment of a moving train.

Fuji Electric has succeeded in developing an AC electrostatic precipitator that suppresses the phenomenon of reentrainment, which has been a longstanding problem for electrostatic precipitators. This paper reports the improvement in particle collection and the development of a high-voltage transformer assembly enabled by the use of an AC field. When particles in the diesel exhaust gas from a vehicle are collected in an electrostatic precipitator, the phenomenon of reentrainment causes the collection efficiency to decrease. By applying a square wave AC voltage, it became possible to realize high particle collection efficiency comparable to that of a DC system for fine particles, and to maintain a longer time of particle collection for large particles by suppressing the reentrainment of particles. Fuji has also developed and commercialized a high-voltage transformer assembly that uses a square wave AC power source. We also evaluated the efficiency of collecting nano-particles, for which the future impact on the human body is a concern.

Fuji Electric has advanced the commercial development of the Stirling Cryocooler, which was first used for infrared night-viewer cooling 30 years ago in Japan. Building on that accomplishment and subsequent continued development, the cryocooler has been installed in earth observation satellites, and is highly regarded as a device for infrared sensor cooling. Fuji Electric's commercially produced pulse tube cryocooler has a high reliability of 50,000 hours, which is used for special machines mounted on satellites in severe space environment as well as for sensor cooling of communication facilities and semiconductor manufacturing equipment. This paper introduces the pulse tube cryocooler and its various applications.

With acceptance of the World Trade Organization (WTO) TBT (Technical Barriers to Trade) agreement, harmonization toward IEC standards for low-voltage electric equipment is advancing at an accelerated rate. However, with the entry into force of the Kyoto Protocol, which concerns the prevention of global warming, the application of energy-savings laws is being expanded to reduce carbon dioxide emissions. Impacted by these changing circumstances, low-voltage circuit breakers are being transformed into commercial products that reflect new trends, such as global standard-compliant circuit breakers, small motor breakers providing safer overcurrent protection, and breakers equipped with a power metering function, for example. This paper analyzes the technical trends concerning low-voltage circuit breakers, and describes Fuji Electric's efforts in this field.

In response to an increasingly globalized customer base and the adoption of IEC standards by domestic Japanese electric equipment manufacturers, IEC-compliant new JIS standards have been issued for molded case circuit breakers (MCCBs) and earth leakage circuit breakers (ELCBs), which are main components of low-voltage electric equipment. By analyzing these trends, Fuji Electric has concluded that new global MCCBs/ELCBs are needed as next-generation lowvoltage circuit breakers to satisfy market needs, and has moved ahead with technical development. This paper introduces the features, main specifications and technical developments of Fuji Electric's new global MCCB/ELCB G-Twin series that complies with global standards.

An underlying concept for the development of new global MCCBs and ELCBs is to provide a single machine that satisfies the performance requirements provided in IEC, JIS, UL, GB and other major global specifications. This paper describes elemental technology developed and applied by Fuji Electric, relating to the optimization of gas flow control and the plastic plate structure in breaking units to realize higher breaking performance, miniaturization of the power supply circuit and the trip coil to provide earth leakage protection when one phase is open, and a reinforced enclosure in consideration of the pressure increase during breaking of short-circuit current.

The RoHS Directive (restriction on use of certain hazardous substances directive) came into effect on February 13, 2003. The impact of the RoHS directive extends beyond the EU's borders, and movements are underway to establish similar regulations in China, South Korea and other countries. In Japan, a law requiring that electrical and electronic equipment be labeled to indicate the presence of specific chemical substances has been established. The new global MCCB and ELCB were developed in consideration of such domestic and overseas environmental regulations. This paper introduces several environmentally responsive technologies for materials that supported development of the new global MCCB and ELCB. Additionally, the control system from material receipt to product shipping that sustains these environmentally responsive technologies is also described.

The trend toward unified global standards, such as conformity between Japanese JIS C 8201 series and IEC60947 series, has triggered the need for globally standardized components. In this paper we will introduce new motor control components such as manual motor starters and combination starters that utilize Fuji's proprietary circuit breaking technology to achieve space savings, higher circuit breaking performance, and type 2 coordination for short-circuit protection.

As a result of the expanded environmental activities of companies which have installed ISO14000 series-compliant environmental management system and the tightening of regulations in accordance with revised energy-savings laws, a rapid installations of energy-saving system support equipment is increasing; and as the result of introducing the greater networking of energy-saving support systems, lowvoltage switchgears are also increasingly being applied to networked systems. This paper describes trends of energy-saving support devices and energy-saving system devices based on compliance with energy conservation laws, introduces low-voltage switchgear networks which are widely used as energy monitoring systems, and discusses future trends of low-voltage switchgear applications.

Fuji Electric has developed a series of power monitoring devices with integrated circuit breakers to provide a selection of optimal devices for the configuration of energy management systems. The FePSU is an optimal device for newly constructed facilities and the JF-Series of electronic power meters is optimal for distribution boards, or for billing use with a tenant board. Moreover, an MPC-Web unit has been developed as a network device for connecting the F-MPC series and the FePSU to an Ethernet. This paper introduces these devi