FUJI ELECTRIC JOURNAL 2002 Vol.75-No.8

Technology for Power Electronics

Trends and Prospects for Power Electronics
Hidetoshi Umida
In the search for solutions to global environmental problems, electric energy is gaining importance for its cleanness. Power electronics is a core technology for electric energy conversion, and its flexibility and controllability hold the key to achieve an economic efficiency through energy and resource savings. This paper describes recent challanges in power electronics and Fuji Electric's efforts toward them.

Application Technique for Reverse Blocking IGBT
Manabu Takei, Akihiro Odaka, Hisashi Fujimoto
The direct linked type converter, typified by the matrix converter, eliminates the need for a DC link circuit, and as such, its application is attracting attention as a method for realizing devices having a smaller size, lower cost and longer life. For the bi-directional switch required in this method, Fuji Electric has developed a reverse blocking IGBT having reverse blocking capability and has realized an anti-parallel connected bi-directional switch. This paper presents a general overview of the reverse blocking IGBT and describes the evaluation results of the commutation and loss when utilized in a direct linked type converter.

Application Technology for Large Capacity 6 in 1 IGBT Module
Satoki Takizawa, Atsushi Yoshida, Kunio Matsubara
For large capacity power electronics equipment such as inverters, Fuji Electric has commercialized the new concept large capacity 6 in 1 IGBT module, having an inverter bridge configuration, and has developed application technology for this module. In comparison to prior products, the large capacity 6 in 1 IGBT module features of a footprint of approximately half the size and an approximate 20 % reduction in loss. Additionally, as application-related technology, Fuji Electric has developed a gate drive circuit that provides protection during the short-circuit mode and which can be connected in parallel, and a custom heatsink that enables this module to achieve a size of approximately 56 % that of previous products.

Technology for Measuring the Current in a Power Pack IGBT
Masaho Furuya, Yasuo Ishiyama
The conversion systems utilized in the fields of industry, power, and electric railways, are required to have small size, low cost, and because they are high capacity systems that support the civil infrastructure, high reliability. Previously, thyristor and gate-turn-off (GTO) devices were mainly used as elements in these high capacity systems. However, insulated gate bipolar transistor (IGBT) devices have recently come into widespread use. Having developed a power pack IGBT that is a high-voltage high-current device, Fuji Electric is presently working on product development. This paper describes the installation of a current sensor at each chip located within the power pack IGBT package and the technology for measuring current during switching.

DC-DC Conversion Techniques for Switching Power Supply
Masakazu Gekinozu, Yukihiro Nishikawa, Takeshi Nozawa
Among switching power supplies used as the power supplies for electronic devices, the current resonant-type conversion method has excellent characteristics of high conversion efficiency and low EMI noise. This paper describes the circuit system and introduces Fuji Electric's proprietary switch element driving methods which are a selfoscillation type and a multi-oscillation type that combines with driving by the transformer's auxiliary winding and driving by a low voltage IC. Techniques for reducing circuit loss during low load operation which is problem for the current resonant type conversion method and techniques for using saturable reactors to precisely control each output in case of multi-output configuration, will also be described.

AC-DC Converter Circuit Technology
Kazuaki Mino, Seiki Igarashi
This paper introduces AC-DC converter circuit technology that is compatible with universal inputs, reduces input current harmonics and is able to realize a high power factor and high efficiency. Fuji Electric has developed a 3-phase 200/400 VAC universal input type power factor correction circuit for large output capacity of 5 kW or more and a single-phase input 100/200 VAC fly-back converter with power factor correction circuit for small output capacity of 200 W or less, thereby achieving a reduction of input current harmonics, a higher power factor and higher efficiency.

Series Connection Technology for High Voltage IGBTs
Yasushi Abe, Koji Maruyama
IGBTs are widely used as switching devices in small- and mediumcapacity conversion systems such as an inverter. It is also becoming increasingly important to use IGBTs in high-voltage large capacity applications where thyristors had been the mainstream. Fuji Electric is also commercializing high-voltage IGBTs, but in order to broaden the range of applications, it is essential to establish a series connection technology for even higher voltage IGBT devices. This paper describes the operating principles, simulated analysis, and test results of the series connection technology developed by Fuji Electric.

Sensorless Control Technology for Permanent Magnet Synchronous Motors
Naofumi Nomura, Hiroshi Ohsawa
Fuji Electric has developed two types of sensorless control methods for the permanent magnet synchronous motor, namely, sensorless vector control and V/f control. In this paper, principles of both types of sensorless control methods are described, experimental results are presented, and the characteristics and performance of each sensorless control method are compared. Advantages of the proposed sensorless vector control include a large starting torque that is 150 % or more of the rated value and high precision torque control that has an error of 3 % or less. Advantages of the proposed V/f control are not only low hardware cost but also high efficiency and response speed, equivalent to that of sensorless vector control, realized by means of the proposed current-based high efficiency control and stabilization control.

Motion Control Technologies
Takayuki Kaneko, Makoto Ichikawa
At Fuji Electric, motion control is being used extensively with electric motor drives as an application of power electronics. These applications are steadily progressing through combining semiconductor technologies such as power modules and LSI devices with rapidly developing control theory, sensor technology, communications, etc. This paper focuses on servo system control technology and introduces the principal technologies and future outlook.

FALDIC- beta Series Compact Servo System
Kazuhisa Nakamura, Minoru Endou, Shinichi Takamoto
In recent years, industrial machinery has advanced to become more highly automated and to have a higher level of performance. However, especially in the field of semiconductor component processing equipment, even higher performance and smaller size are being required in response to the trends toward shortened tact time, higher precision and compactness of the equipment. In response to these demands, Fuji Electric has developed the FALDIC-beta Series, which realizes the worldwide highest level of control performance and smallest dimensions. This paper introduces the functions and features of the FALDIC-beta Series.

DipHunter, an Instantaneous Voltage-drop Protection Unit
Nobuhisa Tanaka, Takafumi Kuninaka, Hideomi Naito
To protect load instruments from Instantaneous Voltage-drop due to lightening or other causes, many users install an uninterruptible power supply (UPS) unit. The battery installed in a small-capacity UPS has a lifespan of approximately 3 years and must be replaced thereafter. This imposes a large financial and labor-intensive burden on users who are operating multiple mini-UPS units. In the newly commercialized instantaneous voltage-drop protection unit, the DipHunter, a capacitor is utilized in the storage unit to eliminate the need for component replacement including the battery. The result is operation that is maintenance- free. This paper introduces the specifications, circuit configuration and features of the DipHunter.

C-GIS 2100, a 24 kV SF6-free Gas-insulated Switchgear
Hideaki Kozono, Hiroshi Kumagai, Takio Kokubun
At the 3rd Session of the Conference of the Parties to the United Nations Framework Convention on Climate Change, on a global warming potential, SF6 gas was shown to exhibit a large greenhouse effect of 23,900 times that of CO2. SF6 gas is one of the gases targeted for reduction. Consequently, there have been calls to develop electric equipment that is free of SF6 gas. Based on this viewpoint, Fuji Electric has commercialized the C-GIS 2100, a 24 kV SF6-free gas-insulated switchgear that uses absolutely no SF6 gas. Based on the technology of the C-GIS 2000 which achieved a large reduction in the amount of SF6 gas, the C-GIS 2100 is built to the same dimensions and incorporates new technology to provide insulation by means of compressed dry air. This paper introduces the SF6-free C-GIS 2100.

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