For those who need a three-phase supply, they are essential. If a single-phase supply is needed, a three-phase generator is uneconomic.
Three-phase is used for loads of more than about 15-20 kVA.
One of the major advantages of using 1 phase over 3 phase is its ease of operation, i.e. in 1-phase there is no problem of load sharing, while in 3-phase one has to share his/her load on all three phases equally or else has to to use three phase equipment.
As far as power station generators (alternators) are concerned, there are no real advantages of single phase over three phase.
As far as small, standby or emergency generators are concerned, a single-phase generator will be smaller and less expensive. If you are considering purchasing a small generator to provide an emergency supply in the event of a power cut to your residence, then a single-phase generator is the only sensible option.
3-phase is good enough.
It allows for a decent energy density in the wires, and you still only need three windings.
4-phase would need one full more winding (a 33 %increase of complexity) at only a little increase of performance.
6-phase would mean a 100% increase in complexity, for not much more increase of performance.
slip rings
A three-phase meter can be used for single phase while the reverse is not the case.
cheap,quiet,long lifetime for motor
You need to match the UPS to the service. If it is three phase you need a three phase UPS, and vice versa for single phase. It isn't a case of being better, it is a situation where you need to match your application.
The only ways this can be done is via a motor generator or a solid state inverter. These can convert single phase power to 3 phase power, however they are generally too large and expensive for home use and motor generators are extremely noisy.In a commercial or industrial location 3 phase power is usually directly available from the power company.
You can take three separate single-phase circuits from a 3-ph generator. Just use one of the live wires plus the neutral to make a single-phase supply. <<>> A three phase generator does not have to be converted to single phase. In electrical terminology any two legs from a three phase system are classed as single phase. No matter what voltage the generator is producing, L1 - L2, L2 - L3, L3 - L1 are classed as single phase legs along with L1 - N, L2 - N, L3 - N. If the generator output voltage is not the voltage that you are looking for use any two legs of the generators output voltage and use a transformer to obtain the voltage that you need.
Single phase inherently requires less equipment (it's cheaper). Three phase motors are more efficient than single phase.
A three-phase meter can be used for single phase while the reverse is not the case.
Over all losses are less in three phase AC system compared to 1 phase. For a given load (KW) 1 phase system would draw more current
The primary advantage is that, for a given load, a three-phase system requires less copper for tranmission/distribution than an equivalent single-phase system would require. Other advantages include the fact that three-phase machines are smaller than single-phase machines of similar rating.
Advantages: it improves frequency stability. phase modulation n demodulation is easy as compared to frequency modulation.
cheap,quiet,long lifetime for motor
Simple hookups to devices you wish to power (2 wires and ground). Most household common devices use single phase.
You need to match the UPS to the service. If it is three phase you need a three phase UPS, and vice versa for single phase. It isn't a case of being better, it is a situation where you need to match your application.
All current is the passage of electric charges from one terminal to another through a conductor so there is no real difference in the type of current that flows in a 3 phase system compared to a single phase system.
Yes. I have a several power generators for sale. Single phase, Three phase, Diesel and Petrol. What sort of power generator are you looking for exactly? Industrial, residential?
the torque requirement of single phase induction motor is less,and it is use for low power applications upto 1 to 10 kw.like in fans,mixiers
In a typical 3 phase system you have multiple voltages and configurations that can be used in either single phase or 3 phase, depending on how the circuit is designed. A single phase system is just single phase. You can have multiple voltages but it is always single phase.For example, in a typical 277/480v 3 phase system you can power 277v single phase lighting or equipment, 480v single phase lighting or equipment (which uses 2 legs of the 3 phase system but operates like any other single phase circuit), or 480v 3 phase motors.When comparing motors, a 3 phase motor will be substantially smaller than a single phase motor of the same horsepower. You can also reverse a 3 phase motor by switching any 2 leads. A single phase AC motor runs in one direction regardless of how the leads are connected.AnswerFor a given load, a three-phase transmission system requires less volume of copper in terms of conductor size, compared to single phase, so it is more economical to use three-phase.