It depicts the output of a generator wound in such a way that three independent single-phase curves are produced, each separated (or out of phase) by 120 electrical degrees. Phase 1 begins at 0 degrees, phase 2 at 120 degrees, and phase 3 at 240 degrees. From 240 degrees on, all three add to a circuit's overall power. The third phase is usually not used.
The voltage across any two points within a generator will be equal in magnitude but opposite in polarity (i.e., positive at one point, negative at another). This is true for all three phases. A diagram showing the relative voltages of the three phases is called a "phasing diagram".
A generator can produce only so much current before it overheats. If you increase the load on the generator, it will need more heat dissipation devices such as larger wires or more surface area from which to dissipate the heat. A generator cannot generate power if it is not turning - it needs to spin at some speed for its magnets to move and thus create current.
As long as the generator is receiving power from the line voltage, it will continue to run even if there is no load attached. This is why generators are often found running when the power is off - they are still getting power from the line voltage even though no one is using them.
Generators come in many different sizes and shapes.
Power is often generated and distributed in three phases, with transformers used to change the voltage. Three coils are tightly attached together and 120 degrees apart in a three-phase alternating current generator. The magnetic field produced by each coil interacts with that of the other two coils, producing a combined magnetic field which passes through the core of the generator.
The strength of the magnetic field determines the amount of current that flows through the coil. Thus, the more powerful the generator, the more current it will flow through its coil.
Consequently, more power will be drawn from the source of energy being converted into electrical power (the utility line), and less energy will be lost due to resistance (heat). Therefore, a powerful generator can keep up with the demand for electricity at any given time, while a weak one would need to be recharged or replaced periodically.
In conclusion, power is generated in a three-phase generator by using three coils with 120 degree angles between them. The stronger the generator, the more current it will flow through its coil.
An alternating current three-phase generator is just three alternating current single-phase generators. These generators operate consecutively with a 120-degree offset between them, two at a time. As a result, the generator generates three waves of alternating current voltage in one cycle, allowing for a stable supply of constant voltage. The three phases are transmitted to a three-phase power distribution system by means of three conductors or cables.
The three-phase power distribution system consists of three separate conductors or cables that transmit each phase of the power signal to different locations. At each location, power is distributed on the appropriate conductor based on which phase of the power signal is highest. For example, if both red wires are hot then it's a ground fault and you should check your circuit breaker or fuse box to make sure it's not damaged. If only the red wire is hot, you have a broken cable or connector on that cable so replace it before any more wires are cut. If all three wires are hot, you have an open circuit somewhere in your home wiring network and you should call a qualified electrician to repair it.
Three-phase power is used in large industrial facilities as well as in homes. It is much more efficient than single-phase power for long-distance transmission because it requires only three conductors instead of one for each phase of single-phase power.
Three-phase generators operate by creating three different waves of alternating current (AC) power that run in sequence, guaranteeing that there is always a continuous flow of energy and that the power level never drops, as with single-phase generators. A special type of transformer called a "transformer/motor" takes the mechanical energy from the turbine or engine and converts it into electrical energy. The three sets of wires coming out of the transformer are then sent to three separate windings on the rotor. Each set of wires sends a signal to trigger the generation of a magnetic field around the stator. These fields add together at the end of the machine, producing power transmission without any contact.
The function of the generator is to convert mechanical energy into electrical energy for general use. This is done by having two sets of poles inside the generator which rotate at high speed against each other. As these two sets of poles move away from one another, they create a magnetic field which passes through the coil of wire forming part of the armature. This creates an electric current in the armature which can be used to power anything that needs electricity such as lights, heaters, etc.
Generators can be divided into three main types: split-phase, three-phase and single-phase. Split-phase generators use two sets of windings on the rotor, one set opposing the other.
When connecting power sources and loads, the phase sequence, which refers to the order in which each phase achieves peak voltage during an alternating current cycle, must be followed. Figure 1 depicts an ABC phase sequence and the associated sine waves for three-phase generators and motors. The direction of rotation of three-phase machines is indicated by the direction in which the phases rise above zero voltage.
For single-phase motors, the B phase is always positive while A and C are negative. For polyphase (more than two) motors, all phases may have the same or opposite polarity. In either case, all phases must be connected to get a net torque that points forward; you cannot have a single-phased motor. If you do connect a single-phased motor, it will act as if it were a single-phase motor, with both A and B having the same magnitude but opposite signs. This would cause the motor to spin in the wrong direction.
The sequence in which the phases reach maximum voltage determines how the currents flow through the machine and what type of machine it is: a generator or a motor. The term "commutation" means the process of switching the current from one conductor to another as it passes through a junction. Commutators do this for multiple conductors at a time on a single brushless DC motor. On a three-phase motor, commutation occurs at every junction where a conductor crosses over another.