FAQs

The generation, distribution, and transmission system together constitute a network called as Power plant. The power plant uses the form of energy such as coal, diesel and converts it into electrical energy. An example of the power system is a grid that supplies power to the other system.

The power grid starts in the places where electricity is made. Electricity once was generated only at central power stations, which usually ran on fossil fuels — coal or natural gas — or nuclear energy. Today more and cleaner options for energy generation are available.
Those options can also cut costs. Distributed energy resources such as rooftop solar panels, can be cheaper because they generate electricity closer to home. That means fewer long power-transmission lines and other expensive grid infrastructure required for centralized distribution.

After electricity is generated, it must be transmitted and distributed to consumers. The network of transmission and distribution facilities makes up the power grid.
Typically, electricity is transmitted at a very high voltage over the power lines that dot the countryside. The higher the voltage, the less current needed for the same amount of power, and thus less loss of electricity. (Resistance to current in the lines creates heat that causes some loss.)
When the electricity reaches customers’ neighborhoods, transformers convert the high-voltage electricity to a lower voltage for distribution to homes and businesses.

The main work of transmission line and distribution line is to transfer power from one place to another but the difference between transmission and distribution line is based on the factors like the type of phase, the distribution line because the wire for transmission line is thick and for distribution line is thin, the transmission line requires three phase supply for carrying electricity and distribution line requires single phase supply for carrying electricity.

Renewable generation poses a dual challenge to electricity system planners and operators. It adds variability and uncertainty in electricity supply, while decreasing the number of on-line controllable generators that can be used to balance supply and demand. For electric power systems to rely primarily on renewable generation, flexible resources will be needed. These resources could be generators, consumers, or storage systems that can reliably increase or decrease supply or demand to maintain balance.

Renewables integration studies often account for spatial correlation of PV generation; however, deciding where to site new PV or transmission is not their focus. For example, Phase one of the Western Wind and Solar Integration Study uses spatial scenarios to vary how much PV is sited by state. But within each state, PV is always sited according to the same principles. States are large enough that moving systems from one to another does not greatly affect the correlation between systems, but the spacing of systems within states will affect this correlation.

The place where electric power produced by the parallel connected three phase alternators/generators is called Generating Station (i.e. power plant).

The ordinary power plant capacity and generating voltage may be 11kV, 11.5 kV 12kV or 13kV. But economically, it is good to step up the produced voltage from (11kV, 11.5kV Or 12 kV) to 132kV, 220kV or 500kV or more (in some countries, up to 1500kV) by Step up transformer (power Transformer).

Generation is the part of power system where we convert some form of energy into electrical energy. This is the source of energy in the power system. It keeps running all the time. It generates power at different voltage and power levels depending upon the type of station and the generators used. The maximum number of generators generate the power at voltage level around 11kV-20kV. The increased voltage level leads to greater size of generator required and hence the cost involved.

Generator loss of excitation fault means that the excitation current provided by the excitation system suddenly disappears completely or partially. After the synchronous generator is out of magnetic, it will be transferred to the asynchronous running state, and the reactive power will be absorbed from the original reactive power conversion.

The causes of generator loss of magnetism fault are: generator rotor winding fault, excitation system fault, automatic demagnetization switch trip and circuit fault.

• Low-excitation and magnetic-loss generators absorb reactive power from the system, causing the voltage of the power system to decrease. If the reactive power reserve in the power system is insufficient, the voltage in some adjacent points in the power system will be lower than the allowable value, which destroys the stable operation between the load and each power supply, and even collapses the power system voltage.
• When a generator is demagnetized, due to the voltage drop, other generators in the power system will increase their reactive power output under the action of the automatic adjusting excitation device, thereby causing some generators, transformers or circuits overcurrent, its backup protection may be mis-operated due to overcurrent, which will widen the scope of the accident.
• After a generator loses its magnetism, due to the swing of the generator's active power and the decrease of the system voltage, it may cause the step-out between the adjacent normal operation generator and the system, or between the parts of the power system, causing the system to oscillate.
• The larger the rated capacity of the generator, the larger the reactive power shortage caused by low excitation and demagnetization, and the smaller the capacity of the power system, the smaller the ability to compensate for this reactive power shortage. Therefore, the greater the ratio of the unit capacity of the generator to the total capacity of the power system, the more serious the adverse effect on the power system.

Coal fires occur in operating coal mines, abandoned coal mines and waste coal piles. They sometimes start because of a nearby blaze, but they can also ignite through spontaneous combustion: certain minerals in the coal, such as sulfides and pyrites, can oxidize and in the process generate enough heat to cause a fire.

In power grids, supply and demand hang in a delicate balance on a second-to-second timeframe. Flexible backup energy sources must stay online at all times to maintain this equilibrium by meeting small variations in demand throughout the day or stepping in quickly if a power plant should suddenly go offline. If supply ever gets too far out of step with demand, devices designed to protect transmission lines and sensitive electronics from damage will quickly trip into action, causing blackouts as they work to shed demand or generation and restore the balance. Currently, certain coal, oil, natural gas, and hydro plants take on the important role of providing these standby capacity services, known as frequency regulation and operating reserves.

The question here is, what would the benefits be if we stopped operating them so inflexibly, if we started using more of their technical capabilities to ‘ramp’ output up and down on different time scales from seconds to hours to seasons?” The answer is less reliance on the gas and coal plants—and more renewable energy integration: Now, as power grids around the world incorporate more and more variable renewable resources like wind and solar, the value of flexibility is increasing. Nuclear plants in places with increasing renewable energy penetration, like Germany, are therefore also moving toward flexible operation.