Household appliances from Korea or any other foreign-made appliances are often designed to operate from an electrical network with an alternating current frequency of 60 Hz. Naturally, the owners of such devices have a reasonable question - can they be used in Russia or other countries with a power supply frequency of 50 Hz? The answer is as simple as the multiplication table: you can! But given that the equipment is designed to be powered by a network with a voltage of 220-230 volts. For example, if the nameplate of a Korean juicer has an operating frequency of 60 Hz and a voltage of 220-230V, then the device will work properly.
The world began to electrify in the late 19th and early 20th centuries. In America, Edison and Westinghouse stood at its origins, Europe was “accustomed” to the electric power industry mainly by the engineers of the German company Siemens. Standard frequencies of 50 and 60 Hz were chosen, in general, relatively randomly from the range of 40...60 Hz. Here the limits of the range were not chosen by chance: at a frequency below 40 Hertz, arc lamps, which at that time were the main electric source of artificial lighting, could not work, and at a frequency above 60 Hz, asynchronous electric motors designed by Nikola Tesla, the most common at that time, did not work. ..
In Europe, the 50 Hz standard was chosen (“golden mean”!), The Americans adopted the 60 Hz standard - arc lamps worked more stable at this frequency. More than a century has passed, arc lamps have become a rarity, but the standards have remained - and this difference of 10 Hz has practically no effect on the performance of electrical equipment. Much more important is the voltage in the electrical network - in many countries it is about half as much as in Russia! And the frequency... in Japan, for example, a third of the prefectures have a standard of 60Hz, and the remaining two-thirds have a standard of 50Hz.
We can safely say that the performance of household appliances does not depend on the frequency of the power supply. From the point of view of physics in general and electrical engineering in particular, this is quite obvious: at the shaft of a 60 Hz AC electric motor connected to a 50 Hz network, the rotational speed will decrease by only a few percent; slightly reduce the power of the electric motor itself. In other words, it will work in a gentle mode - in the same, for example, cold-pressed screw juicers, this is only for the better.
In devices with DC motors, the frequency of the supply network does not play any role at all - the rectifier diodes installed in the power supply can handle voltage of any shape and "hertz". The difference in the magnitude of the rectified voltages arising due to a change in the frequency of the supply network will be simply scanty; in addition, the rectified voltage is usually stabilized by the electronic "stuffing" of the device.
All of the above is absolutely true for household appliances that have a built-in or external switching power supply. The situation is even simpler if the power supply includes a conventional step-down transformer - its output characteristics change slightly from changes in the voltage frequency in the primary winding. The performance of another type of device - heating - does not at all depend on the frequency of the supply network, for such devices the magnitude of the mains voltage is much more important ...
Appliances designed to be powered by a 60 Hz mains supply can be safely connected to a 50 Hz mains supply. This, by the way, is confirmed by one not too well-known fact: if you open some rather old device with an electric motor - a vacuum cleaner, a hair dryer, a mixer, a cold-pressed juicer - and carefully read the inscriptions on the nameplate of the engine, you can see: "mains frequency ... 50-60 Hz"! The frequency of 60 Hz is used in technology from Korea, USA, Japan and some other countries. Therefore, if you ordered, for example, a juicer from Korea, now you know that even though its operating frequency differs from our networks, you can connect the device!
In fairness, it should be noted that there is still a type of electrical appliances that it is better not to include in the domestic electrical network - this is electrical equipment that uses a single-phase asynchronous motor. And the point here is not even that for such electric motors, the rotation speed does not depend on the frequency of the supply network, but on the load applied to the shaft - the fact is that, due to the principle of their operation, asynchronous electric motors are very sensitive to the frequency of the network at start-up. Designed for 60 Hz, the "asynchronous" at 50 Hz simply will not start ... For example, the same juicer from Korea may have the same 60 Hz in its characteristics, but if it has a different type of engine, then be prepared for the fact that the device will not turn on. The same applies to any equipment from Korea, Japan, USA.
Here's what else you need to pay attention to when choosing equipment from Korea, Japan, Taiwan, the USA and a number of other countries - the requirements for the magnitude of the supply voltage! In many countries that produce equipment (Korea, Japan, etc.), the power grids have an operating voltage of 110 V, and not 220, as we have. You can turn on a device designed for 110 V without a transition transformer only once - the first and last ... at best, the device will “burn out”, at worst, it will explode right in your hands! Therefore, if the juicer is from Korea or another country, and has an operating voltage of 110V, then such a device is not suitable for our networks. When choosing a cold-pressed juicer, pay attention to the operating voltage of the device - it must be 220V!
Hz (Hertz)In relation to energy, frequency is understood as the frequency of alternating electric current in the power system. Or else they say "industrial frequency". We and in Europe have a frequency of 50 Hz. In the USA and Japan 60 Hz. What does it mean? This means that 50 times per second, the electric current flows with increasing-decreasing (according to a sinusoid) in one direction, 50 times in the other. A few words why the industrial frequency is exactly 50 or 60 Hz. It's just that the frequency of the current appears due to the rotation of the generator rotor. If you increase the rotor speed (and, accordingly, the frequency in the power system), you need to make the design of the generator more durable. And it is impossible to increase strength to infinity, any structural materials have a limit. In short, 50-60 Hz is a balance of many technical limitations.
When there are no problems with the frequency, there is no mention of this value in journalistic materials. But this may not always be the case. What can the frequency deviation from the nominal lead to (we have 50 Hz)? To a serious accident! When the frequency is higher than the nominal 50 Hz, centrifugal forces of greater magnitude act on the rotating rotor of the generator and turbine than are inherent in their design. This can lead to their destruction. Of course there is automation. If F reaches 55 Hz, the unit will automatically disconnect from the mains to prevent damage. If the frequency is below 50 Hz, there is a decrease in the performance of all electric motors (reduction in their rotational speed) connected to the power system - both those that provide the operation of escalators in the supermarket, and those that rotate the conveyor belt in the factory, and those that provide the production process electricity at power plants. The last one is the most dangerous. Frequency decreases, power generation decreases, which leads to an even greater decrease in frequency, as a result - power plants can simply “go to zero” (if the frequency drops to 45 Hz), this is a complete repayment, as they say blackout. Of course, there is automation here too. In order to prevent a deep decrease in frequency, some consumers are automatically turned off, including “household” ones. The above is of course extreme cases of accidents. But the frequency can also deviate by smaller values. This is also bad. And the power system provides automation to avoid this. Here I painted a little how it works, if you are interested, read it.
A little more theory (be patient, since we have reached here). The frequency in the system, the value of exactly 50 Hz can be only in one case - if at each moment of time exactly as much active power is generated as it is consumed. If this balance is violated, the frequency "leads" to one side or the other, and this leads to an accident. Imagine any other enterprise (furniture factory, bakery, car factory) and the same task - every fraction of a second to produce exactly as much product as consumers need. You can see how complex the production of power engineers is. What is interesting here - if the frequency is higher than 50 Hz, then the generators produce more power than the power of all consumers, well, this is easily treated - the output at power plants is reduced, and that's all. If the frequency is below 50 Hz, the power consumption is greater than the generated power. And if the frequency is always below 50 Hz, then there is a power shortage in the power system. Power plants were not built on time - this is a big problem.
Today, Russia provides us with a high-quality frequency of 50 Hz. It is there that high-speed frequency regulators with an impact on Russian stations are located. When you turn on the iron, somewhere far away in Russia, the generator is loaded with an additional 1.5 kW, and vice versa (this is a bit simplified, but for the most part it is). Neither in the UES of Kazakhstan, nor in the energy systems of Central Asia, today, there are no systems that allow you to keep the frequency "in tune" at the level of 50 Hz. If we separate from Russia (electrically), our frequency will fluctuate, which is very bad.
And one more thing - the frequency is a global factor. It is the same everywhere in the power system. And in Kazakhstan and throughout Russia (the part that is part of the EEC), it is the same at the same time. If in some part the frequency has changed, then this part is electrically disconnected (due to an accident or for other reasons) and is isolated from the main power system.
Just don’t tell me: “Dad, who were you talking to right now?”. Just kidding, of course :) Let's move on.
EEC - Unified Electric Power System. This is a set of power plants, substations and transmission lines connected by a single common technological mode of operation. In short, everything that works "in parallel" and is interconnected (everything that is interconnected by power lines) constitutes the EEC. And although there is the UES of Kazakhstan and the UES of Russia, in fact it is more of a political division, “electrically” it is all one energy system, which used to be called the UES of the USSR. But, for example, the power system of Australia is not included in our UES, since it is not connected with us by power lines.
CL - cable power line - a cable is laid underground, of course with powerful insulation. The cost of cable lines is much more expensive than overhead lines, therefore in the USSR, it was customary to lay cable lines only inside settlements so as not to disfigure the appearance. Such savagery, as in other countries, when all the intestines are unwound through the streets, you will not find here.
The very first cable line was designed not to transmit electricity, but to transmit signals. In 1843, the US Congress announced a tender for the construction of an experimental telegraph line, which was won by Morse (known to us by the "Morse code"), so they decided to lay the line underground. However, due to the fact that Morse's companion decided to save money on insulation for wires, instead of a line, there was one continuous short circuit (such situations still happen today, when merchants begin to control techies). And more than enough money has already been spent. Engineer Cornell, participating in the project, suggested such a way out of the situation - to place poles along the route, and hang bare telegraph wires directly on these poles, using the necks of glass bottles as insulators. This is how an overhead telegraph line appeared, an electric overhead line is practically its copy, and even today the design has not fundamentally changed.
VL - overhead power line. Serves for the transmission of electricity through wires that are suspended from the support by means of insulators. The higher the operating voltage of the overhead line, the higher the supports and the greater the number of insulators in the garland. There is only one insulator on the 6.10 kV overhead line, 2 insulators on the 35 kV overhead line, 6 insulators on the 110 kV overhead line, 12 insulators on the 220 kV overhead line, 24 insulators on the 500 kV overhead line, so in appearance it is not difficult to determine the operating voltage of the overhead line.
hydroelectric power station - a hydroelectric station (it can also stand for a hydraulic power station, try not to use the colloquial "hydro station" - in my opinion, it sounds vulgar). A hydroelectric power station is a power plant where electricity is obtained by converting the energy of water (the flow of water turns a turbine). There are not many large hydroelectric power stations in Kazakhstan. If compared in terms of capacity, then all HPPs will make up no more than 10% of all generating capacities in the UES. This is bad. In order for the energy system to be self-sufficient, it is necessary to have at least 20-30% of hydroelectric power stations in the system, but what can you do - water resources are not enough. The advantage of a hydroelectric power station is its high maneuverability. Such stations can quickly pick up the load and also quickly dump it (this is necessary for accurate frequency control at the level of 50 Hz). What hydroelectric power plants do we have?
| Moscow time | frequency Hz |
|---|---|
| 01-09-2019 00:00 | 50.03 |
| 01-09-2019 01:00 | 50.00 |
| 01-09-2019 02:00 | 49.97 |
| 01-09-2019 03:00 | 49.97 |
| 01-09-2019 04:00 | 49.99 |
| 01-09-2019 05:00 | 50.01 |
| 01-09-2019 06:00 | 50.02 |
| 01-09-2019 07:00 | 49.99 |
| 01-09-2019 08:00 | 50.00 |
| 01-09-2019 09:00 | 50.02 |
| 01-09-2019 10:00 | 50.01 |
| 01-09-2019 11:00 | 50.01 |
| 01-09-2019 12:00 | 50.02 |
| 01-09-2019 13:00 | 49.99 |
| 01-09-2019 14:00 | 50.03 |
| 01-09-2019 15:00 | 49.98 |
Information on the frequency of electric current in the UES of Russia, published by JSC "SO UES" in accordance with Decree of the Government of the Russian Federation dated January 21, 2004 No. 24 "On Approval of Information Disclosure Standards by Entities of the Wholesale and Retail Electricity Markets" (as amended by Decrees of the Government of the Russian Federation dated 04/21/2009 No. 334 and dated 08/09/2010 No. 609), is located in the subsection "Information on the value of the frequency of electric current in the UES of Russia" of the section "Disclosure of information on the functioning of the UES of Russia"
Frequency electric current is one of the indicators of the quality of electric energy and the most important parameter of the power system mode. The frequency value shows the current state of the balance of generated and consumed active power in the power system. The operation of the Unified Energy System of Russia is planned for a nominal frequency of 50 hertz (Hz). The continuity of electricity production, the inability to store energy on an industrial scale and the constant change in consumption volumes require the same continuous monitoring of the correspondence between the amount of electricity produced and consumed. The indicator characterizing the accuracy of this correspondence is the frequency.
When maintaining the UES mode, fluctuations in the power balance constantly occur, mainly due to the instability of consumption, and also (much less often) when generating equipment, power lines and other elements of the power system are turned off. These deviations in the power balance lead to frequency deviations from the nominal level.
An increased frequency level in the power system relative to the nominal one means an excess of generated active power relative to the consumption of the power system, and vice versa, a lower frequency level means a lack of generated active power relative to consumption.
Thus, the regulation of the power system mode by frequency consists in constantly maintaining the planned power balance by manually or automatically (and more often both at the same time) changing the load of generators of power plants so that the frequency remains close to the nominal one all the time. In emergency situations, when the reserves of generating equipment of power plants are not enough, limiting the load of consumers can be applied to restore an acceptable frequency level.
Regulation of the frequency of electric current in the UES of Russia is carried out in accordance with the requirements established by the Standard of JSC "SO UES" STO 59012820.27.100.003-2012 "Regulation of frequency and active power flows in the UES of Russia. Norms and requirements” (as amended on January 31, 2017) and the national standard of the Russian Federation GOST R 55890-2013 “Unified energy system and isolated energy systems. Operational dispatch control. Regulation of frequency and active power flows. Norms and requirements” (hereinafter referred to as the Standards).
According to the specified Standards, in the first synchronous zone of the UES of Russia, the frequency values averaged over a 20-second time interval should be maintained within (50.00 ± 0.05) Hz, with the admissibility of finding frequency values within (50.0 ± 0.2 ) Hz with frequency recovery to the level of (50.00±0.05) Hz in no more than 15 minutes. High requirements for maintaining the frequency are due to the need to harmonize frequency deviations with the planned reserves of the throughput capacity of the controlled sections of the UES under normal conditions. For the UES of Russia, which is characterized by long intersystem links included in the controlled sections, more stringent standards for maintaining the frequency and, accordingly, the power balance, allow the maximum use of the bandwidth of these links.
All rotating mechanisms in synchronously operating parts of the power system (turbines, generators, motors, etc.) have a nominal design speed proportional to the nominal frequency in the network. It is known that the nominal mode of operation of all rotating mechanisms is the most effective in terms of their efficiency, reliability and durability. Deviation from the nominal speed of rotation leads to undesirable effects in the operation of equipment of power plants and consumers (the occurrence of increased vibrations, wear, etc.), a decrease in their efficiency and reliability. For different equipment, there are maximum permissible frequency deviations from the nominal. Maintaining the frequency at a level close to the nominal one ensures maximum efficiency of power equipment operation and maximum safety margin for power systems.
The supply voltage is 220/230 V single-phase and 380/400 V three-phase in the Russian Federation. Why 220 and 230V, 380V and 400V are the same. 50Hz / 60Hz. Why is the supply voltage in electrical networks variable? Why do transmission networks (power lines, power lines) have very high voltage (high voltage)? Why is the voltage lower in consumer networks? Why is that. Electrical jargon and common sense.
First, why is the supply voltage in electrical networks variable, and not constant? ? The first generators at the end of the 19th century produced a constant voltage, until someone (smart!) realized that it was easier to produce a variable during generation and rectify it at consumption points if necessary than to produce a constant during generation and give birth to a variable at consumption points.
Second, why 50 Hz? Yes, it just happened to the Germans at the beginning of the 20th century. It doesn't make much sense. In the US and some other countries, 60 Hz. ()
Third, why do transmission networks (power lines) have very high voltages? There is a sense here, if you remember, then: the power loss during transportation is equal to d(P)=I 2 *R, and the total transmitted power is equal to P=I*U. The share of losses from the total power is expressed as d(P)/P=I*R/U. The minimum share of total power losses, i.e. will be at maximum voltage. Three-phase networks transmitting high power have the following voltage classes:
Fourth: what is the nominal designation V="Volt" (A="Ampere") in AC voltage (current) circuits? This is rms=effective=rms=rms value of voltage (current), i.e. such a value of direct voltage (current), which will give the same thermal power at a similar resistance. Indicating voltmeters and ammeters give exactly this value. The maximum amplitude values (for example, from an oscilloscope) are always higher in absolute value than the current one.
Fifth, why is the voltage lower in consumer networks? There is a sense here too. Practically permissible voltages were determined by the available insulating materials and their. And then there was nothing to change.
What is "three-phase voltage 380/400V and single-phase voltage 220/230V"? There is attention. Strictly speaking, in most cases (but not in all), a three-phase household network in the Russian Federation is understood as a 220 (230) / 380 (400) V network (occasionally there are household networks 127/220 V and industrial 380/660 V !!!). Incorrect, but occurring designations: 380/220V; 220/127 V; 660/380V!!! So, further we are talking about a conventional network of 220 (230) / 380 (400) Volts, to work with the rest - it would be better for you to be an electrician. So for such a network:
Sixth, why are 220V and 230V the same, why are 380V and 400V the same? Yes, because the PUE and GOSTs for the quality of the supply voltage are taken as quality voltage +/- 10% of the nominal value. Yes, and electrical equipment is designed for this.
The site project warns: if you have no idea about the safety measures when working with electrical installations (), it’s better not to start yourself.
The supply voltage is 220 V single-phase and 380 V three-phase in the Russian Federation. 50 Hz. Why is that. Electrical jargon and common sense.
First, why is the supply voltage in electrical networks variable, not permanent? The first generators at the end of the 19th century produced a constant voltage, until someone (smart!) realized that it was easier to produce a variable during generation and rectify it at consumption points if necessary than to produce a constant during generation and give birth to a variable at consumption points.
Secondly, why 50 hz? Yes, it just happened to the Germans at the beginning of the 20th century. It doesn't make much sense. In the US and some other countries, 60 Hz. ()
Third, why transmission networks (power lines) have very high voltage? There is a sense here, if you remember, then: the power loss during transportation is equal to d(P)=I 2 *R, and the total transmitted power is equal to P=I*U. The share of losses from the total power is expressed as d(P)/P=I*R/U. The minimum share of total power losses, i.e. will be at maximum voltage. Three-phase networks transmitting high power have the following voltage classes:
Fourthly: what is the nominal designation V \u003d "Volt" (A \u003d "Ampere") in AC voltage (current) circuits? This is rms=effective=rms=rms value of voltage (current), i.e. such a value of direct voltage (current), which will give the same thermal power at a similar resistance. Indicating voltmeters and ammeters give exactly this value. The maximum amplitude values (for example, from an oscilloscope) are always higher in absolute value than the current one.
Fifth, why is the voltage lower in consumer networks? There is a sense here too. Practically permissible stresses were determined by the available insulating materials and their dielectric strength. And then there was nothing to change.
What's happened "three-phase voltage 380V and single-phase voltage 220V"? There is attention. Strictly speaking, in most cases (but not in all), a three-phase household network in the Russian Federation is understood as a 220/380V network (occasionally there are household networks 127/220 V and industrial 380/660 V !!!). Incorrect, but occurring designations: 380/220V; 220/127 V; 660/380V!!! So, further we are talking about a conventional 220/380Volt network, to work with the rest - it would be better for you to be an electrician. So for such a network:
The DPVA.info project warns: if you have no idea about the safety measures when working with electrical installations (see PUE), it’s better not to start yourself.
