Case 1 - Substation for electrical utility company

This is for an electric utility company’s substation on a remote island. The low potential of the system raised concerns about voltage drops due to the inrush current of the power receiving transformer. The Inrush Limiter T1 was installed to prevent this. Figure 3-2 shows measured waveforms, recorded during field validation testing, of the inrush current and voltage drop with and without the Inrush Limiter.
Transformer specifications Tr.1: 10MVA 22kV/6kV
Tr.2: 6MVA 22kV/6kV
After repeated opening and closing tests without the Inrush Limiter, the inrush phenomenon showed an inrush current of 411 A, and voltage drop of 14.8%. With the Inrush Limiter, the inrush current was suppressed to 91A and the voltage drop was held to within 1.9%.
Figure 3-1
Figure 3-2

Case 2 - Electrical Power Receiving Substation at a Major Chemical Manufacturer

A major chemical manufacturer owns an electrical furnace and their own electrical power receiving substation. The substation consists of several banks of power receiving transformers. When they energized a transformer in one of the banks, the other banks (connected to the primary side of the power system) showed a significant voltage drop. The Inrush Limiter T1 was installed to avoid this voltage drop and the disturbances it causes on manufacturing activities. Figure 3-4 shows measured waveforms, recorded during field validation testing, of the inrush current and voltage drop with and without the Inrush Limiter.
Transformer specifications 22MVA 44kV/11kV
After repeated opening and closing tests without the Inrush Limiter, the inrush phenomenon showed an inrush current of 1,514A, and voltage drop of 7.1%. With the Inrush Limiter, the inrush current was suppressed to 83A and the voltage drop was held to within 0.2%. This manufacturer used a circuit breaker with a resistor for many years to suppress inrush currents in their 66-kV electrical power receiving substation. (The 66-kV serial resistor is used with an auxiliary circuit breaker to limit inrush current when the breaker is closed.) The Inrush Limiter has rendered these resistors obsolete, which are now removed.
Figure 3-3
Figure 3-4

Case 3 - Substation for Wind Power Generators

Studies at an interconnected substation for a wind power generating system revealed voltage drops of 20% when the transformer was connected. It was necessary to suppress this to within 5%. The Inrush Limiter achieved less than 3%. (Each of the following countermeasures to achieve 5% or less were rendered obsolete:
  1. Installation of a diesel generator
  2. special designed transformer (change in leakage impedance, etc.)
  3. Use of a serially-connected resistor and circuit breaker
Figure 3-6 shows measured waveforms, recorded during field validation testing, of the inrush current and voltage drop with and without the Inrush Limiter.
Transformer specifications 30MVA 33kV/66kV
After repeated opening and closing tests without the Inrush Limiter, the inrush phenomenon showed an inrush current of 839A, and voltage drop of 19.5%. With the Inrush Limiter, the inrush current was suppressed to 164A and the voltage drop was held to within 1.5%.
Figure 3-5
Figure 3-6

Installed Base

Customer Application Transformer Specifications Units
Voltage [kV] Windings
Capacity [MVA]
Asahi Kasei Co., Ltd., Nobeoka Plant Chemical factory: Heavy electrical power user. Used for a own extra high-voltage substation. 60/12 Y-Δ 1
33
Kyushu Electric Power Company, General Research Laboratory Applied as a portable 1
Kyushu Electric Power Company, Azetsu Substation Utility substation for island: 6.6 kV to 66 kV receiving substation Station 1,2&4 6.6 / 66 Y-Δ 3
25
Utility substation for island: 6.6 kV to 66 kV receiving substation Station 3 66 / 22 Y-Y 1
20
Asahi Kasei Co., Ltd., Nobeoka Plant Chemical factory: Heavy electrical power user. Used for a own extra high-voltage substation. 66/11 Y-Δ 1
17.1
Asahi Kasei Co., Ltd., Nobeoka Plant Chemical factory: Heavy electrical power user. Used for a own extra high-voltage substation. 60/11 Y-Δ 1
30 / 40
Kyudenko Corporation Wind power generating station: Electrical power transmission 66 / 22 Y-Δ 1
14
Nishinippon Plant Engineering and Construction Co., Ltd. Wind power generating station: Electrical power transmission 66 / 22 Y-Δ 1
20
Kyudenko Corporation Wind power generating station: Electrical power transmission 66 / 22 Y-Δ 1
20
Asahi Glass Co., Ltd., Chiba Plant Glass manufacturing factory: Heavy electrical power user, using an electric furnace for glass manufacturing 11 / 0.534 Δ-Y-Δ 4
14.38×2
Showa Denko KK, Omachi Plant Electric furnace for manufacturing factory: Heavy electrical power user, using electric furnace for carbon graphite electrodes manufacturing. 44 / 14 Δ-Δ 3
41.5
J-POWER, Electric Power Development Co., Ltd. Wind power generating station: Electrical power transmission 66 / 33 Y-Δ 1
29.5
Railway Technical Research Institute R&D Center: Research and development for power transmission into railway technologies and labor science. for R&D 1
Oji Paper Co., Ltd., Nichinan Factory (shipped via Meidensha Corp.) Paper manufacturing factory: Switching electrical power source between own powerhouse and power company 66 / 11 Y-Y-Δ 1
32/32/15
Nisshin biomass power station Electric power selling: Switching electrical power transmission between own biomass power station and power company. 22 / 6.6 Δ-Δ 1
7
Kyushu Electric Power Company, Inc., Urakuwa Substation Utility substation for island: 6.6 kV to 22 kV receiving substation 6.6 / 22 Y-Y 1
15
Kyushu Electric Power Company, Inc., Ojika Substation Utility substation for island: 22 kV to 6.6 kV receiving substation Station 1 22 / 6.6 Y-Y 1
10
Station 2 22 / 6.6 Y-Y 1
6
JNC Corporation, The First Substation Chemical company: Switching electrical power source between own powerhouse and power company. Station 1 66 / 18.4 Y-Δ 1
25
Station 2 66 / 18.4 Y-Δ 1
8
Station 3,4 18.4 / 3.3 Δ-Δ 1
12.5
JNC Corporation, Tsuru Power Plant Hydroelectric generating station: Electrical power transmission. 63 / 6.6 Y-Δ 1
12
Showa Denko KK, Omachi Factory Electric furnace for manufacturing factory: Heavy electrical power user, using electric furnace for carbon graphite electrodes manufacturing. 44/11 Δ-Y 1
22
39 / 0.57 Δ-Y 1
22
KYOCERA Communication Systems Co., Ltd Photovoltaic power generating station : Electrical power transmission. 66 / 22 Δ-Y 1
30
Denka Company Limited Oomuta factory Electric furnace for manufacturing factory: Heavy electrical power user, using electric furnace. 66 / 0.18 Y-Δ⇔ Δ-Δ 1
9×3
Shimonoseki City [FUJI ELECTRIC CO., LTD. Kansai branch office] Incineration system 22 / 6.6 Δ-Δ 1
3.5
Daido Steel Co., Ltd. Shibukawa factory Electric furnace for manufacturing factory: Heavy electrical power user, using electric furnace. 38 / 0.57 Δ-Δ-Y 1
2.8×2
J-POWER Electric Power Development Co., Ltd. Wind power generating station : Electrical power transmission. 72 / 22 Y-Δ 1
23
Shimonoseki City [FUJI ELECTRIC CO., LTD. Kansai branch office] Incineration system 22 / 6.6 Δ-Δ 1
3
Meiden Plant Systems Corporation Photovoltaic power generating station : Electrical power transmission. 66 / 22 Y-Δ 1
21
Suzuka Electric Works Co., Ltd. Photovoltaic power generating station : Electrical power transmission. 22 / 6.6 Δ-Δ 1
10
Showa Denko KK, Omachi Factory Electric furnace for manufacturing factory: Heavy electrical power user, using electric furnace for carbon graphite electrodes manufacturing. 44 / 42~29 Y-Y 1
32.3
Denka Company Limited Omi Plant Electric furnace for manufacturing factory: Heavy electrical power user. 60/0.255~0.145 Y or Δ/Δ
50⇔60 Hz
1
10×3
Toray Battery Separator Film Co., Ltd Battery film factory: Heavy electrical power user. Using for an own high-voltage substation. 6.6/0.415~0.240 Δ-Y 3
2/0.5
Central Glass Co., Ltd. Ube factory Tie transformer for manufacturing factory: Heavy electrical power user. 6.6/3.3 Δ-Δ 1
20
Daido Steel Co., Ltd., Chita Plant Electric furnace for manufacturing factory: Heavy electrical power use. 22/1.0 Δ-Δ 1
4.5
Asahi Kasei Co., Ltd., Nobeoka Plant Chemical factory: Heavy electrical power user. Using for an own extra high-voltage substation. 66/11 Y-Δ 1
30 (40)
Denka Company Limited Omi Plant Electric furnace for manufacturing factory: Heavy electrical power user. 63/0.340~0.140 Y or Δ/Δ
50⇔60 Hz
2
58
Daido Steel Co., Ltd., Chita Plant Electric furnace for manufacturing factory: Heavy electrical power use. 22/1.0 Δ-Δ 1
Unknown

Wind Power Station

Customer Application Transformer Specifications Units
Voltage [kV] Windings
Capacity [MVA]
Goto Tamanoura Wind Power Co., Ltd. Wind power generating station : Electrical power transmission. 66/22 Y-Δ 1
14
Kyusyu Wind Power Co., Ltd. Wind power generating station : Electrical power transmission 66/22 Y-Δ 1
20
Kudenko Shin-energy Co., Ltd Wind power generating station : Electrical power transmission 66/22 Y-Δ 1
20
Electric Power Development Co., Ltd. Kaminokuni Wind Power Plant Wind power generating station : Electrical power transmission. 66/33 Y-Δ 1
29.5
Electric Power Development Co., Ltd. Ooma Wind Power Plant Wind power generating station : Electrical power transmission. 72/22 Y-Δ 1
23

Photovoltaic Power Station

Customer Application Transformer Specifications Units
Voltage [kV] Windings
Capacity [MVA]
Green Power Investment Corporation Futtsu PV Plant, Chiba Photovoltaic power generating station : Electrical power transmission. 66/22 Δ-Y 1
30
X-ELIO Japan Yono PV Plant, Iwate Photovoltaic power generating station : Electrical power transmission. 66/22 Y-Δ 1
21
Suzuka Electric Works Co., Ltd. Kameoka PV Plant, Kyoto Photovoltaic power generating station : Electrical power transmission 22/6.6 Δ-Δ 1
10
SB Energy Corp. SoftBank Hiroshima Sera Solar Park Photovoltaic power generating station : Electrical power transmission. 22/6.6 Δ-Δ 1
5.0
Solar park in Shirakawa, Fukushima Photovoltaic power generating station : Electrical power transmission 66/33 Δ-Y 1
34

Biomass Power Station

Customer Application Transformer Specifications Units
Voltage [kV] Windings
Capacity [MVA]
Oji Green Energy Nichinan Co., Ltd. Paper-manufacturing factory: Switching electrical power source between own powerhouse and power company. 66/11/3.3 Y-Y-Δ 1
32/32/15
Nissin Biomass Power Co., Ltd. Electric power selling: Switching electrical power transmission between own biomass power station and power company 22/6.6 Δ-Δ 1
7
Hibikinada Energy Park Electric power selling: Switching electrical power transmission between own biomass power station and power company 66/14.1 Δ-Δ 1
115
IDI Hibikinada Electric power selling: Switching electrical power transmission between own biomass power station and power company. 66/14.1 Δ-Δ 1
115
Asahi Kasei Co., Ltd., Nobeoka Plant Electric power selling: Switching electrical power transmission between own biomass power station and power company. 66/13.4 Δ-Δ 1
61

Hydraulic Power Station

Customer Application Transformer Specifications Units
Voltage [kV] Windings
Capacity [MVA]
JNC Corporation Minamata Factory Tsuru Hydroelectric Power Plant Hydroelectric generating station : Electrical power transmission. 63/6.6 Y-Δ 1
12
Yamagata Prefectural Government Kamimuro Hydroelectric Power Plant Hydroelectric generating station : Electrical power transmission. 6.6/0.420 Δ-Y 1
75
Kyushu Electric Power Co., Inc. Miyazaki Hydroelectric Power Office Applied as a portable Unknown 2

Power Company’s Substation

Customer Application Transformer Specifications Units
Voltage [kV] Windings
Capacity [MVA]
Kyushu Electric Power Co., Inc. Asetsu Substation, Nakadori Island Utility substation for island: 6.6kV to 66kV Receiving substation Station 1 6.6/66 Y-Δ 3
Station 2
25
Station 4
Utility substation for island: 66kV to 22kV Receiving substation Station 3 66/22 Y-Y 1
20
Kyushu Electric Power Co., Inc. Urakuwa Substation, Nakadoori Island Utility substation for island: 6.6kV to 22kV Receiving substation. 6.6/22 Y-Y 1
15
Kyushu Electric Power Co., Inc. Ojika Substation, Ojika Island Utility substation for island: 22kV to 6.6kV Receiving substation Station1 22/6.6 Y-Y 1
10
Station2 22/6.6 Y/Y 1
6

Public Facility

Customer Application Transformer Specifications Units
Voltage [kV] Windings
Capacity [MVA]
Shimonoseki City Okuyama Factory Incineration system, Shimonoseki City: 22/6.6 Δ-Δ 1
3.5
Shimonoseki City Okuyama Factory Incineration system, Shimonoseki City: 22/6.6 Δ-Δ 1
3

Research Institute

Customer Application Transformer Specifications Units
Voltage [kV] Windings
Capacity [MVA]
Kyushu Electric Power Co., Inc. Research Institute Applied as a portable Unknwon 1
RTRI (Railway Technical Research Institute) R&D center: Research and development for power transmission into railway technologies and labor science. Unknown 1

Railway Company’s Substation

Customer Application Transformer Specifications Units
Voltage [kV] Windings
Capacity [MVA]
Central Japan Railway Co., Ltd Honnagashino Substation Central Japan Railway Co., Ltd Honnagashino Substation 6.6/1.2 Δ-Δ-Y 1
2.2
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