What is 50 Hz? Why do we use 50 Hertz?
Production and distribution of electricity based on three-phase AC current was developed by Nikola Tesla in the 19th century. At the time Tesla developed this system, Thomas Edison was providing energy to the grid through his own DC system. Tesla argued that the AC system was more efficient than the DC system and the losses were less. Tesla, together with the Westinghouse company, of which Tesla was included, made great efforts to use AC transmission.
Tesla had determined the frequency of 60 Hertz and the voltage level of 240 V in his system. However, Edison, who held the electrical energy market at that time, was at odds with Tesla because of economic interests and pride. During the transmission of electricity in the DC distribution system, large losses were experienced over long distances and the cost was increasing as much. In time, they switched to the AC system due to these negativities. The system was started to be used in three phases, but the voltage level was accepted as 110 V and the frequency 60 Hertz.
Establishing the first power generation facility in Europe, the German AEG company started production with 110 V voltage. Over time, this choice turned out to be inappropriate. Because a 2 kW motor at 110 V voltage level was drawing approximately 18.18 A current from the network. At 220 V voltage, 9.09 A current was drawn. In this case, the cross-sections of the conductors used in the transmission of electricity increased, leading to an increase in cost. Another issue was that the motors draw current above their nominal values during the first development. Therefore, circuit breakers had to be installed in distribution systems. In order to open these negativities, 220 V has been passed over time.
Tesla had predicted a frequency of 60 Hertz in its system, but the reason why the experts of AEG company, which established the first system in Europe, where we later joined, preferred 50 Hertz is known as the decimal number system.
When using 50 Hertz, electricity is approximately 20% less efficient in generating and 10-20% less efficient in transmission. In addition to these, it requires the use of larger windings and magnetic core material in the winding of the coils. Over time, these problems have grown, creating chain problems one after another. Having a monopoly on electricity generation in those years, AEG company preserved the 50 Hertz frequency level and thus spread to the whole European continent.
Using a device manufactured according to 50 Hertz in a 60 Hertz system is less damaging, but even if the voltages are equal, a 60 Hertz clock or the tape may not operate at 50 Hertz current, their motors turn slower and heat up. Although many electronic devices are protected against voltage changes, if a device designed for 110 volts is connected to 220 volts, it may be out of hand. Manufacturers design some devices to work with both characteristics, but hairdryer type devices must work with one of these two options.
It is the standardized frequency of the alternating current. So what is the frequency?
The number of periods the maximum current makes in 1 second is called frequency.
- F = 1 / T or T = 1 / f
f = Frequency is the number of periods per second, measured in Hz.
- T = Period, measured in seconds.
- T / 2 = Half period (alternans)