Sakuma Dam

Sakuma Dam
Sakuma Dam
	Electric Power Development Company
Dam and spillways
Type of dam	Gravity dam
Impounds	Tenryū River
Height	155.5 meters
Length	293.5 meters
Dam volume	1,120,000 m3
Reservoir
Creates	Lake Sakuma
Total capacity	326,848,000 m3
Catchment area	4156.5 km2
Surface area	715 hectares
Sakuma Power Station; Shin Toyoshi Power Station

The Sakuma Dam (佐久間ダム, Sakuma damu) is a

hydroelectric power station.^[1]

Nearby a frequency converter station is installed, allowing interchange of power between Japan's 50 Hz and 60 Hz AC networks.

History

The potential of the Tenryū River valley for hydroelectric power development was realized by the

Taishō period that development began on the Tenryū River. Private entrepreneur Fukuzawa Momosuke founded the Tenryūgawa Electric Power (天竜川電力, Tenryūgawa Denroku), which later became Yasaku Hydroelectric (矢作水力電気, Yasaku Suiroku Denki) before it was nationalized into the pre-war government monopoly Japan Electric Generation and Transmission Company (日本発送電株式会社, Nippon Hassoden K.K.) in 1938. The first dam on the main stream of the Tenryu River, the Yasuoka Dam was completed in 1935. This was followed by the Iwakura Dam in 1938. The Hiraoka Dam was started in 1938, but not completed until 1951 due to the start of World War II

.

After the end of World War II, the

commemorative postage stamp

.

Design

Sakuma Dam is a hollow-core concrete

Shin-Toyone Hydroelectric Power Station

, with a rated capacity of 350,000 kW and 1,200,000 kW respectively.

Surroundings

The Sakuma Dam Reservoir is a popular attraction for canoeing and camping, due to its proximity to downtown Hamamatsu and ease of access. The surrounding area is part of the Tenryū-Okumikawa Quasi-National Park.

HVDC frequency converter

The western part of Japan uses 60 Hz and the eastern part uses 50 Hz as

ASEA. In 1993 it was converted to use light triggered thyristors, which were installed in the same valve hall

that had contained the mercury arc valves.

Each inverter consists of two series-connected six pulse inverters forming a twelve pulse inverter. As in many other HVDC facilities, quadrivalves (serial connections of four valves forming a unit) are used. Each valve consists of 7 series-connected thyristors designed for a current of 2,500 A and a blocking voltage of 6 kV. Each of the two inverters uses 84 thyristors.

The station has three transformers on the 60 Hz side. One transformer is the power supply of the station, and two 275 kV/55 kV transformers feed the valves. The transformers have their low-voltage windings connected one in a delta and other in a wye. All these transformers share a common tank. On the 50 Hz side, two 275/54 kV transformers, in separate tanks, feed the valves, again with one in delta and the other in star connection of the low-voltage windings.

The DC smoothing reactor has an inductance of 0.12 H and is designed for a current of 2,400 A.

On each side filters for the 5th, 7th, 11th and 13th harmonic exist, which consist of a series connection of a capacitor, an inductor and a resistor. In addition, a high pass filter is used, which consists of a capacitor switched in series with a coil to which a resistor is switched in parallel.

References

^ "Hydropower & Dams in South and East Asia" (PDF). Hydropower and Dams. p. 9. Retrieved 3 October 2010.

Japan Commission on Large Dams. Dams in Japan: Past, Present and Future. CRC Press (2009).
ISBN 978-0-415-49432-8

[1] "Hydropower & Dams in South and East Asia" (PDF). Hydropower and Dams. p. 9. Retrieved 3 October 2010.

[1]