Today, power electronics is a key technology in all areas where energy is“ created,”“ connected” or“ used,” from social infrastructure that supports lifelines to home appliances. There are also high expectations of it bringing about a low-carbon society through high-efficiency conversion in energy creation such as mega-solar power plants and energy saving in motor drives, and so on.
Fuji Electric has developed and provided to society products that make full use of power electronics technology for various electromotive power based equipment, transportation and logistics infrastructure, as well as uninterruptible power systems for data centers that support Internet society.
This issue provides an outline of power electronics equipment applying SiC (silicon carbide) power devices to dramatically improve efficiency and reduce size and weight, fundamental technology in power electronics technology development, and international standardization for the global market.
|Preface to the Special Issue on “Power Electronics” |
Johann W. Kolar
Professor, Swiss Federal Institute of Technology Zurich
|Power Electronics: Current Status and Future Outlook |
Power electronics technology and its applied products are widespread in all fields of society and also raising expectations as means to realize energy conservation. Meanwhile, the environment surrounding power electronics equipment is undergoing great changes as shown by the advent of SiC power devices, which are expected to lead dramatic advances in power electronics equipment in place of the conventional silicon devices, and requirements for compliance with international standards in the global market. In order to meet these diverse development needs and support the acceleration of development, Fuji Electric is working on product development by utilizing platforms and the establishment of a development environment that makes full use of advanced simulation technology. In addition, Fuji Electric is developing and offering power electronics equipment intended for various fields such as motor applications, rotating machines, transport equipment and power supply equipment, including the development of products that utilize SiC power devices.
|Mega Solar PCS Incorporating All-SiC Module “PVI1000 AJ-3/1000” |
OSHIMA, Masafumi; MAEDA, Tetsuya; MURATSU, Hiroki
In recent years, solar power generation has come to need greater power generation performance. Power conditioning sub-systems (PCSs) are the core of the generation, and they require high efficiency, reliability to continue to generate electricity, and a reduction of total cost. Fuji Electric has developed a highly efficient PCS for mega-solar plants by incorporating an All-SiC module consisting of silicon carbide metal-oxide-semiconductor fi eld-effect transistors (SiC-MOSFETs) and SiC Schottky barrier diodes (SiC-SBDs), which are the next-generation semiconductors.
|Large-Capacity, High-Efficiency 3-Level UPS for North America “7000HX-T3U” |
KAWASAKI, Daisuke; HAMADA, Ippei; SATO, Atsushi
Due to the development of information and communications systems in the information society in recent years, the data center market is expanding both in Japan and abroad. At the same time, there are increasing needs for uninterruptible power systems (UPSs) to ensure stable system operation. “7000HX-T3U,” which has been developed for the North American market, is a large-capacity, high-efficiency UPS using a 3-level power conversion circuit with a rated voltage of 480 V. By using Fuji Electric’s original AT-NPC 3-level insulated gate bipolar transistor (IGBT) module, the UPS has achieved a maximum efficiency of as high as 97%. It provides high reliability, as with the conventional models, and also supports UL and NEC standards which must be complied with in North America.
|General-Purpose Inverters Meeting Global Standards, “FRENIC-HVAC/AQUA Series” and “FRENIC-Ace Series” |
KONO, Hiroyuki; MIGAKI, Takumi; KAIMI, Takashi
In recent years, general-purpose inverters have been required to be multi-functional. Even in the areas where dedicated controllers or specialized variable speed drives were conventionally used, in an increasing number of cases customized general-purpose inverters are being adopted. The demand for product globalization is also increasing. To satisfy these needs, Fuji Electric has developed the “FRENIC-HVAC/AQUA Series” and “FRENIC-Ace Series” general-purpose inverters that meet global standards. These products are supporting our globalization by featuring a customized logic function as standard and introducing multi-language support and region codes. They also comply with international standards regarding noise immunity and functional safety.
|690-V Inverters Equipped with SiC Hybrid Module, “FRENIC-VG Stack Series” |
SATO, Kazuhisa; TAKANO, Makoto; NOMURA, Kazuki
Fuji Electric offers 690-V stack type of the “FRENIC-VG Series” that has the highest-level performance in the industry. The 690-V inverters have seen high demand from the marine industry, overseas chemical plants, mining and water treatment facilities and their conventional capacities were between 90 and 315 kW. Now capacities from 355 to 450 kW have been added to the lineup. Incorporating a SiC hybrid module with low power dissipation prevents the product from becoming larger due to capacity enlargement, and keeps the product width to 220 mm. Connecting multiple stacks in parallel makes it possible to drive multi-winding motors up to 2,700 kW. Having a direct parallel connection enables large-capacity single-winding motors to be driven up to 1,200 kW.
|Fuji Electric’s Top Runner Motor – Loss-Reduction Technology of “Premium Efficiency Motor” |
TACHI, Norihiro; KOIBUCHI, Hirobumi; TAKAHASHI, Kazutoshi
Motors are a key component indispensable for social and industrial activities. They consume electric power that accounts for nearly 40% of the global energy consumption. Consequently, improving motor efficiency is a challenge for the major countries of the world. In Japan, the Top Runner Program was introduced in April 2015 to regulate motor efficiency. The “Premium Efficiency Motor” that Fuji Electric has developed satisfi es the efficiency regulation value through various loss-reduction technologies including an optimized slot shape and the adoption of magnetic steel that dissipates less power. This is an environmentally friendly product achieving low noise as well as high efficiency.
|Inverter-Integrated Motor |
UTSUNO, Makoto; MATSUI, Kohei
Recently, energy saving by improving motor efficiency and adopting variable speed control systems have come to be accelerated. Fuji Electric has developed an inverter-integrated motor, which incorporates inverter functions into a motor. In addition to adopting a high efficient motor, variable speed operation with inverter control achieves signifi – cant energy saving effect. Moreover, it achieves downsizing by the incorporation. The energy-saving effect amounts to a reduction of 45% (1,923 kWh per year) from standard motors with IE1 class efficiency and 43% (1,742 kWh per year) compared to IE3 “Premium Efficiency Motors.”
|Technologies to Reduce Size and Weight of Power Electronics Equipment for Rolling Stock |
TAKIZAWA, Masamitsu; NISHIJIMA, Tomotaka
Recently, there have been strong demands for power electronics equipment mounted on devices and units to be installed in rolling stock to have a smaller size, less weight and also to save energy. Fuji Electric has been meeting these demands by improving its cooling and equipment mounting technologies. For isolation transformers, which had limitations in terms of their downsizing, we have adopted a medium-frequency isolation circuit technology and direct current power supply system and implemented an optimized design to reduce the ratio of their installation space to the unit volume, thereby realizing further size and weight reduction. We offer in Japan and overseas power electronics equipment that uses the latest technologies such as propulsion systems and auxiliary power supplies for rolling stock including the Shinkansen
|Latest Trend and Safety and Reliability Technology of Rolling Stock Doors |
TUMEZAWA, Kotaro; TERASAKI, Tomio; INATAMA, Shigeki
Fuji Electric has developed and commercialized a door operating equipment (linear motor system and FCPM system) with a simplified mechanism by applying the motion direction of a motor to the linear motion of the side sliding door. The door operating equipment for the side sliding door of rolling stock is an important component that ensures the safety of passengers when they are boarding, alighting and traveling, and it may affect trains’ punctuality. Consequently, the system is required to be safe, reliable, high functional, and maintenance saving. These characteristics have been achieved in a safety evaluation that was conducted at the design stage and that included failure mode effect analysis and hazard analysis, and they have also been ensured with control technologies such as triple feedback, external force suppression and push-back control.
|Railway Static Power Conditioner for Shin-Kurobe Substation of Hokuriku Shinkansen |
OSO, Hiroshi; KANEKO, Tomomi; SUZUKI, Akio
Fuji Electric has delivered a railway static power conditioner (RPC) to Shin-Kurobe Substation, located between Nagano and Kanazawa on the Hokuriku Shinkansen Line. This equipment is composed of an inverter and an inverter transformer. While the trains run, it compensates for the unbalanced load in 3 phases and voltage fluctuation by interchanging power between two circuits in the direction of Nagano and Kanazawa. It also compensates for the harmonic current generated by trains. We developed a high-capacity downsized inverter by engaging a water-cooling system and equalizing the current sharing of insulated gate bipolar transistors (IGBTs). We adopted a gapless transformer for the inverter transformer to achieve low-noise level and high reliability.
|Multifunctional On-Shore Power Systems for Harbors and Shipyards |
MIYASHITA, Tsutomu; UMEZAWA, Kazuyoshi; JOICHI, Hiroshi
In recent years, even in the maritime and shipbuilding industries, reduction of environmental impact has come to be required. To meet that issue, Fuji Electric has developed a multifunctional on-shore power system equipped with both power supply functions for the on-board power systems and load testing functions for the on-board generator. Since this system is installed outdoors, we examined its placement to make maintenance easy and give it an effective cooling system and decided to install the main facilities in a container of use outdoors. The containers can be connected in parallel so that it is easy to enlarge the capacity. The facility’s characteristic control functions include abilities to supply power to on-board power systems at the desired voltage/ frequency and to conduct a load test for the on-board generators via load resistor or power regeneration.
|Simulation Technology for Power Electronics Equipment |
MATSUMOTO, Hiroyuki; TAMATE, Michio; YOSHIKAWA, Ko
As there is increasing demand for higher efficiency and power density of the power electronics equipment, it has become more important to develop the equipment by connecting the design of wiring structure, cooling structure and electromagnetic interference (EMI), which were previously designed individually. Fuji Electric is working on the realization of such a connection by using a device simulation model. This simulation model makes it possible to understand the switching characteristics after the implementation into circuits. In addition, the simulation result can effectively be applied to the design of the other components. Since it is now possible to estimate the temperature of a component and an EMI noise level precisely at the beginning of the design stage, the cooling structure and EMI filters can be developed effectively shorter period than before.