0
Why the standard ac frequency distribution is 50 Hz or 60 Hz and not a large figure like 500 or 1000 Hz?
Wiki User
∙ 9y ago
Whether you use 50 Hz and 60 Hz in the place where you live or work happens to be for historical reasons.
If you want to see more detailed information please see the Related Questions shown below.
Wiki User
∙ 14y ago
Wiki User
∙ 9y agoThe frequency of AC power is determined by the speed of the prime mover driving the generator, be it a large hydroelectric driven generator, a steam driven generator or a gasoline engine driven generator.
One Hertz is one cycle per second. A cycle is equal to 360 degrees of rotation of a generator drive shaft. In other words one Hertz is one complete rotation of a generator.
50 Hz means a generator is revolving 50 times a second or 3,000 revolutions per minute (RPM). A 60 Hz generator is rotating at 3,600 RPM.
1,000 Hz would require the generator to rotate at 60,000 RPM, which is too fast for mechanical prime movers.
There are 400 Hz systems used in aircraft and other applications but they are self contained small systems.
The way the power distribution grid works requires all generators connected to the grid to be running exactly the same speed as well as be in phase with each other. Being in phase means that every generator connected to the grid is at exactly the same point of rotation as every other generator. So when one generator is at 10 degrees of rotation every other generator is at 10 degrees of rotation. Any generator trying to connect to the grid, that doesn't match the speed and phase alignment, appears to all the other generators as a very large load, essentially a short circuit. The oncoming generator would be producing power in opposition to all the other generators causing very large current flows, damaging equipment. There are safety devices that prevent such things from happening.
Historically, once power grids started to develop in a geographical area or a country they became locked into whatever frequency their generators were rotating. Any town or city that wanted to join the grid would have to match the grids frequency and voltage.
A higher frequency system would require a whole new grid dedicated to the new frequency.
<<>> The frequency of a power system is chosen to satisfy conflicting requirements. A lower frequency results in lower power loss in transmission over distances, but lower frequencies require more massive Transformers. Power grid systems also require lower frequencies to maintain stability in the generators.
In transport aircraft 400 Hz is used as the power frequency because the distance is short and the major requirement is to reduce the mass of electrical components. On the other hand in national power supply systems a lower frequency is used so that power can be distributed over long distances.
Some long-distance power lines run on DC (zero frequency) to reduce the power losses as far as possible. Since expensive rectifiers must be used, this is done only if the distances and power levels
warrant it.
Add your answer:
Earn +20 pts
When was the first large scale distribution of electricity?
Arguably, the first large scale distribution of electricity was on August 26, 1895 when water flowing over the niagra fall was diverted to turbines.
What is a frequency?
Frequency really means how often a wavelengths repeats itself and is actually related to time. Different wavelengths can be of a single frequency or they can contain multiple, yet separate frequencies at the same time. One of the ways that wavelengths can be identified, is simply by the frequency. By and large, the frequency used will also tell you a bit about the application in which it's used, as well as the type of frequency you can expect it to be, such as AM, FM, TV, Satellite, or some other type of communications. This is largely in part because there is a published frequency spectrum chart that's available in print and online that identifies most uses for a specific frequency range.
Why can you not get limeaway in anystores in Canada?
If a company has not sold it's distribution rights for an area or country then the product does not get promoted or imported into that market. If that is the case contact the company and as about distribution rights. Canada is a very large market geographically and very diverse culturally. As a result many companies have several different distribution areas in Canada.
What is the size of a donkey?
donkeys are about the size between a cow and a goat, mammoth donkeys on the other hand are as big as a horse
How many beds does a standard hotel room have?
Typically, a standard hotel room has one large bed (a double or queen bed). However, it may have two smaller beds instead.
A grouped frequency distribution is used when the range of data values is relatively small. True or false?
False. When the range is large you would use a grouped frequency distribution.
What is simple frequency distribution?
Simple frequency distribution is a method of organizing large data sets into more easily interpreted sets. An example is organizing sample test scores by the individual scores.
Why are unequal class intervals used in frequency distribution?
to avoid a large number of empty classes?
Name of the very famous distribution that describes the frequency of the number of times a number comes up in a series of dice rolls?
The binomial distribution which, for large numbers of rolls can be approximated by the Gaussian distribution.
When graphing a distribution of phenotypes for a continuous trait a broad curve implies?
a large standard deviation
When to use z or t-distribution?
If the sample size is large (>30) or the population standard deviation is known, we use the z-distribution.If the sample sie is small and the population standard deviation is unknown, we use the t-distribution
What is grouped frequency distribution?
If the observations are grouped together into classes, then the number of observations for each class gives the grouped frequency distribution (FD). This kind of FD is particularly important when the data are continuous so that you are likely to have very small frequencies for a very large number of values.
Why use unequal class intervals in a frequency distribution?
they may be necessary in certain situations to avoid a large number of empty ,or almost empty, classes.
What is a grouped frequency distribution used for?
To simplify analyses for large data sets. To simplify analyses for large data sets. To simplify analyses for large data sets. To simplify analyses for large data sets.
The standard error of the mean is the standard deviation of the sampling distribution of the sample mean?
a large number of samples of size 50 were selected at random from a normal population with mean and variance.The mean and standard error of the sampling distribution of the sample mean were obtain 2500 and 4 respectivly.Find the mean and varince of the population?
Which of the following is true regarding the sampling distribution of the mean for a large sample size?
It has the same shape, mean, and standard deviation as the population.
How is frequency distribution useful to us?
I suspect you are referring to a sample frequency distribution.Providing that the sample size is sufficiently large there are various kinds of information that can be gleaned from one:the approximate range of values in the populationthe location of the population as measured by the value that appears most often in the frequency distribution-known as its modethe likely shape of the population's distribution, in particular whether it is symmetric or skewedobviously how values of the population variable are distributedwhether there are any curious peaks or valleys, even when the sample size is largethe amount of variation around the central value
