General Overview

Optimum Energy Utilization Technology− Contributing to More Comfortable and Enriched Life−
Brief Overview
We developed energy utilizing technology supporting rich life and industry, and satisfying comfort and environmental
requirement. We also conducted performance evaluation for changes in ambient temperature, room temperature, and water temperature using the environmental test facility for Heat Pump Water Heater introduced in FY2006 for spreading of new Eco-cute system forcold area application.
We also conducted research for rationalized system operation and control when a large number of distributed power generations such as photovoltaic power generation are penetrated into the utility distribution lines in the future. We improved the detection
system for islanding of distributed power generation to verify its effectiveness from both viewpoints of simulation analysis and experiments and finally clarified, by simulation, rationalized voltage control method effectively responding to individual conditions atpenetrated area of distributed power generation and its penetrated volume.

Achievements by Research ThemeEnd use technology○ Customer energy utilization support
・ For practical realization of residential indoor thermal environment design tool, we improved the tool to evaluate detailed heating
conditions using various types of floor heating and air conditioning as well as energy consumption.
○ Evaluation of system operational performance of new Eco-cute model・ We evaluated operating performance of various new Eco-cute systems to difference in ambient temperature, room temperature,
and water temperature using the environmental test facility for evaluate of Heat Pump Water Heater introduced in FY2006.
(Fig.1)○ Inverter with SiC device
・ Targeting an inverter for distributed power source interconnection, we developed a prototype device (3.3 kW) applying SiC
diode to achieve maximum efficiency of 96.4%, and obtained possibility to reduce the device volume by 15% compared toconventional device. (Fig.2)○ SiC power semiconductor・ To realize a large capacity and low-loss SiC semiconductor devices, we developed crystal growth technology of high purity andthick SiC film having purity and thickness that correspond to 20-30 kV class withstanding voltages. (Fig.3)○ Compact secondary battery utilization
・ We measured energy consumption at complete electrical housing combining Eco-cute, IH cooking heater, and others for actual
condition survey considering family structure.
Next generation grid technology● Technology for autonomous demand area power system
・ We improved the detection system for islanding of distributed power generation to verify its effectiveness from both sides ofsimulation analysis and experiment.
・ We clarified, by simulation, combination of proper voltage control systems corresponding to penetration area and penetration
rate of distributed power generation. (Fig.4)

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Optimum energy utilization technology

End use technology
Epitaxial growth rate [μm/h]

A
250
200

more than 10 times higher
growth rate (250 om/h)than con-ventional
technology is achieved.

sourcegas

150

hotwallsubstrate

10050

Schematic of the reactor

00.000

0.002

0.004

0.006

Input SiH4/H2 ratio

Fig.3 Growth technique of highly-pure and thickFig.1 Performance evaluation of new

single crystal SiC film

Eco-cutes

Achieved efficiency of 96.4%

Reduction
in volume by 15%
体積15%低減

Efficiency [%]Conventional Si inverter

9897 試作機
Prototype
SiC inverter（SiCダイオ ード）
96
95
94
93
92
91
9089
88
87
86
0.0 0.3 0.6 0.9 1.2 1.5

Prototype SiC inverter (37cm×14cm×24cm)

Siダイオード適用機
Conventional
Si inverter

1.8

2.1

2.4

2.7

3.0

3.3

3.6

Output [kW]Fig.2 Prototype inverter using SiC diodes (3.3kW)

Next generation grid technology

Fig.4 Classification of proper distribution line voltage control method according toDG penetration rate and area.

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