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Comments on 50-Hz Frequency “History” Article

Question on the Rheinfelden Plant

figure 1. The Niagara Falls Power Company (from E.D. Adams, Niagara Power, 1927, vol. 2, p. 251).

figure 1. The Niagara Falls Power Company (from E.D. Adams, Niagara Power, 1927, vol. 2, p. 251).

I read and thoroughly enjoyed Gerhard Neidhöfer’s article “50-Hz Frequency: How the Standard Emerged from a European Jumble,” in the July/August 2011 issue (G. Neidhöfer, “50-Hz Frequency,” IEEE Power Energy Mag, vol. 9, no. 4, pp. 66–81, July/Aug. 2011). Prof. Dr. Neidhöfer has accomplished a marvelous task in assembling the historical facts to tell how 50 Hz became standard on four and a half continents. The photographs used in the figures are fascinating.

I have a question concerning the Rheinfelden hydroelectric power plant (Figure 7 on page 73). The text above the figure states “Half of the units were designed to produce dc . . . . for adjoining electrochemical plants . . . . ” Did all of the dc units produce the same voltage? Note on Figure 1, showing the system in 1897, that five of the applications used rotary converters to obtain dc as the three industries in Niagara Falls all used different dc voltages.

Craig Woodworth

A Personal Involvement

I have read with special interest Prof. Dr. Neidhöfer’s article concerning the emerging of the 50-Hz frequency (IEEE Power & Energy Magazine, July/August 2011) as I was personally involved in its application.

In my first day as engineer at the Timisoara Electricity Utility in Romania, in November 1949, Prof. Dr. Cornelius Miklosi, then my general manager, gave me the task to study the problem of normalization of the frequency in the local electric system. The situation was then that the local system was operating at 42 Hz, and the distribution system was partially two phase as a consequence of the initial planning by the Ganz Society in the early period of electricity generation and distribution in the Austro-Hungarian Empire. This situation led to many difficulties in the operation of the system, especially for the consumers.

The Timisoara Electricity Utility had taken the first steps to normalize the frequency and the distribution system in 1925, but the subsequent financial crisis and World War II halted the program. So, in 1949 the normalization was still frozen and had to be resuscitated. The need to restart and to finish the normalization became urgent because of the precarious situation of the electricity supply to the town of Timisoara (population about 250,000) and of the whole region.

In 1953, very modest financial aid was received, and I was given the task of being the manager of the project. As a result, I was obliged to study all specific aspects of the transition from 42 Hz to 50 Hz and the transition from a two-phase to a three-phase distribution system. I learned then an important part of the facts described by Prof. Dr. Neidhöfer in his article.

It was a very difficult and exciting task, but I had the good luck to have at my side a group of talented young engineers and technicians whose contributions were essential.

In a paper presented at the Polytechnic University of Timisoara in December 2003 in memory of the 50th anniversary of the normalization, I described in detail the problems we had to solve and how we did it.

Thomas Laszlo

The Wynau Plant

figure 2. The first hydroelectric power station on the river Aare at Wynau, built by Siemens & Halske in 1894–1896, with five generators and 4,000 hp. (From the Archive Siemens Switzerland, Zurich, used with permission.)

figure 2. The first hydroelectric power station on the river Aare at Wynau, built by Siemens & Halske in 1894–1896, with five generators and 4,000 hp. (From the Archive Siemens Switzerland, Zurich, used with permission.)

I would like to comment on the July/August 2011 history article “50-Hz Frequency,” authored by Prof. Dr. Gerhard Neidhöfer, which I found to be of particular interest. As a member of the staff of Energiedienst AG, Rheinfelden, and project manager for the new Rheinfelden hydroelectric power plant, I am proud that our former 1898 hydropower plant played an important role in the history of 50-Hz frequency.

Perhaps it is also interesting to note that two years earlier, in 1896, there was another large hydroelectric plant, Wynau on the Swiss Aare River, with a total capacity of 3,000 hp producing 50-Hz three-phase power.

Figure 2 shows the interior of the Wynau hydroelectric plant as it appeared in 1896.

Armin Fust

Author’s Response

The coexistence of dc and ac technology and the establishment of 50 Hz as one of the standard frequencies is a fascinating chapter in the history of electric power generation. I was pleased to receive personal communications from readers of this magazine in response to my essay that appeared in the July/August 2011 issue of IEEE Power & Energy Magazine and, in particular, to read the three letters to the editor that provided additional information or brought up further questions.

Mr. Craig Woodworth (Tonawanda, New York), whose contributions in the field of technohistorical matters I hold in high esteem, asks for the definite dc-unit voltages in the 1898 hydropower plant Rheinfelden. I forwarded the question to a current crew member of the power plant, who kindly searched for those values and found that the two connected electrochemical industries had used different dc voltages, that is, 120−143 V and 210−230 V, respectively, produced by independent turbine sets with dc-generators.

Dr. Thomas Laszlo (Haifa. Israel) describes an exciting process that took place in the Romanian district of Timisoara in 1953−1957, when the original frequency of 42 Hz and two phases (a prominent relic of the Austro-Hungarian Empire) were gradually abandoned in favor of the common standard, i.e., 50 Hz and three phases. In fact, this process must have entailed a highly challenging series of actions, since electric power supply had to be assured permanently to all consumers during this critical changeover of the system. Dr. Laszlo’s survey paper from 2003, 50 Years Ago: Transition of the Local Power System of Timisoara to Normalized Voltage and Frequency, brings to light a remarkable technical adventure. I read the article with great admiration for this truly exceptional achievement, accomplished under such abnormal electric system conditions. Congratulations on this very fine article!

Dr. Armin Fust (Laufenburg, Switzerland) of the Rheinfelden power generation company, in charge of the new hydropower station at the German-Swiss border, rightly draws attention to another historical hydroelectric power plant of substantial capacity that was in operation two years before the Rheinfelden plant started its operation. Indeed, this earlier power plant, in Wynau on the Aare River (the largest tributary to the Rhine up to this point), was to become the first large-scale run-of-river power plant in Switzerland. The generated electricity was already at three phases and 50 Hz, but the total capacity of 3,000 hp remained far below the 17,000 hp of Rheinfelden, the latter capacity having been attained by virtue of the higher hydraulic power of the Rhine River. This is why Rheinfelden is commonly considered to be the first large-scale hydroelectric power plant in Europe, ranking directly after the Niagara power station in North America and why, thanks to an expanding cooperation with other power plants, it gradually became the nucleus of the European interconnected network.

Gerhard Neidhöfer

Rights to Education

Never before, except perhaps at the very birth of the electric power industry, have we seen such advancements and transformative concepts and technology entering the modern electric power system. Today across the globe, and certainly in North America, there is a fervent push to transform the power generation and transmission business. The massive integration of variable generation technologies, such as wind power and solar photovoltaic systems, are presenting new and exciting challenges for the analysis, modeling, planning, and operations of the modern power system. The increasing complexity of the power system and the rapid improvement in telecommunications and digital monitoring and control are also shaping a new future for the next generation of power engineers as they embark on research and development in the application of more intelligent and centralized control of the bulk power system.

What is the fuel behind all this development? I believe it is the innate human desire and destiny to carry forward an ever-advancing civilization. And what guides that desire? Education!! How else can our young and bright new generation fulfill this and their many other destined accomplishments if they are not afforded the basic human right to higher education? The mission statement of our Society emphasizes the need for the IEEE Power & Energy Society to stay at the forefront of scientific and engineering knowledge. This is surely not possible without an increasing focus on the quality and standards of our educational institutions. Can you imagine the destiny of this country, or the globe as a whole, if our youngest and brightest were denied access to higher education? As sad as this would be, it is happening presently in some parts of the world, one specific example is the country of my birth, Iran. As a member of the Bahá’í faith (a worldwide religion with an estimated 6 million members in over 200 countries, with the basic teachings of the unity of God, the unity of religion, and the unity of humankind) in Iran, under the current government, I would be denied access to higher education.

My family left Iran in 1980 to start a new life in Australia. Were it not for my parents’ bold decision to make such a move and literally start their lives again from scratch while in their early 40s, my brother and I would never have had the opportunities afforded us as a result of the university education we received in Australia. Today I continue to benefit from that education and am indebted to my teachers and mentors, both in Australia and in the United States. That the Bahá’í youth of Iran are systematically denied any opportunity for higher education, even in their own homes, is likely unfathomable to many in North America, Europe, and Australasia. The best means of bringing to an end such gross injustice is to shed the light of international awareness upon it.

We should all be grateful for the freedoms we enjoy in countries such as Australia and the United States. Education is the basic right of all human beings, and everyone should have the opportunity to seek higher education. Education is one of the foundations of civilization and one of the means of reducing ignorance, prejudice, and poverty. My wife and I were recently blessed with the birth of our first child, and this brought all these sentiments to mind even more vividly. It is my ardent prayer that he, and all the children and youth in the world, may grow up in a world that is rid of all prejudice and ignorance, and that we may yet fully realize the dream of Rev. Martin Luther King Jr. throughout the entire planet. After all, we are all citizens of one country, the planet Earth.

Pouyan Pourbeik

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