In the last article, we introduced a resolution of DC AC. the “war” ended with the victory of AC. therefore, AC gained the spring of market development and began to occupy the market previously occupied by DC. After this “war”, DC and AC competed in the Adams hydropower station at Niagara Falls.
In 1890, the United States built the Niagara Falls Adams hydropower station. In order to evaluate various AC and DC schemes, a national and international Niagara Power Commission was established. Westinghouse and Ge took part in the competition. Finally, with its rising reputation after the victory of the AC / DC war and the talents of a group of excellent scientists such as Tesla, as well as the successful test of AC transmission in Great Barrington in 1886 and the successful operation of alternator in larffen power plant in Germany, Westinghouse finally won the manufacturing contract of 10 5000P AC hydro generators. In 1894, the first 5000P hydro generator of Niagara Falls Adams power station was born in Westinghouse. In 1895, the first unit was put into operation. In the autumn of 1896, the two-phase alternating current generated by the generator was transformed into three-phase through Scot transformer, and then transmitted to Baffalo 40km away through three-phase transmission system.
The hydro generator of Adams power station at Niagara Falls was designed by B.G. lamme (1884-1924), chief engineer of Westinghouse, according to Tesla’s patent, and his sister B. lamme also participated in the design. The unit is driven by fournellon turbine (double runner, without draft tube), and the generator is a vertical two-phase synchronous generator, 5000hp, 2000V, 25Hz, 250r / mln. The generator has the following characteristics;
(1) Large capacity and long size. Before that, the single unit capacity of hydro generator did not exceed 1000 HPA. It can be said that the 5000bp hydro generator of Adar hydropower station in Niagara Falls was not only the largest hydro generator with single unit capacity in the world at that time, but also the key first step in the development of hydro generator from small to large.
(2) The armature conductor is insulated with mica for the first time.
(3) Some basic structural forms of today’s hydro generators are adopted, such as vertical umbrella closed structure. The first 8 sets are of the structure in which the magnetic poles are stationary outside (pivot type), and the last two sets are changed to the current general structure in which the magnetic poles rotate inside (field type).
(4) Unique excitation mode. The first one uses the DC power generated by the nearby DC steam turbine generator for excitation. After two or three years, all units will use small DC hydro generators as exciters.
(5) The frequency of 25Hz was adopted. At that time, the Ying rate of the United States was very miscellaneous, from 16.67hz to 1000fhz. After analysis and compromise, 25Hz was adopted. This frequency has become the standard frequency in some parts of the United States for a long time.
(6) In the past, the electricity generated by power generation equipment was mainly used for lighting, while the electricity generated by Niagara Falls Adams power station was mainly used for industrial power.
(7) The long-distance commercial transmission of three-phase AC has been realized for the first time, which has played an exemplary role in the transmission and wide application of three-phase AC. after 10 years of operation, 10 5000bp water turbine generator units of Adams hydropower station have been comprehensively updated and transformed. All 10 units have been replaced with new units of 1000HP and 1200V, and another 5000P new unit has been installed, so that the total installed capacity of the power station reaches 105000hp.
The battle of direct AC of hydro generator was finally won by AC. Since then, the vitality of DC has been greatly damaged, and AC has begun to sing and attack in the market, which has also set the tone for the development of hydro generators in the future. However, it is worth mentioning that a remarkable feature of the initial stage is that DC hydro generators are widely used. At that time, there were two kinds of DC hydro motors. One is a low-voltage generator. Two generators are connected in series and driven by one turbine. The second is the high-voltage generator, which is a double pivot and double pole generator sharing one shaft. The details will be introduced in the next article.
Post time: Sep-13-2021
