How do Electrical Power Systems work?

Sometimes. you might wonder how electricity is generated, what those transmission towers that you see around are for or how electricity gets to your home. Well, it’s all a network; a network of units working together to achieve the goal of delivering electricity. And this network is called the electrical power system

What is an electrical power system?

An electrical power system is a network of units or components which generates, transfer and utilizes electrical power. In other words, an electrical power system would have a unit that generates power, one that transfers it and the other that consumes it.

There are many types of electrical power systems around the world, and they all differ in how their power is generated and transferred to the consumers. And they all come in different sizes and capacities.

Examples of power systems are the home backup power system which can constitute of a Generator, cables and home appliances. The generator generates the power which passes through the cables to your home appliances.

Another example is the power system in automobiles which constitutes an alternator, battery and a starter. The battery provides power to the starter motor; starter motor starts the engine and keeps it running; the running engine makes the alternator generate power to keep battery charging. And it all continues in cycles. In this power system, the alternator, which is the generator, provides power to the battery which powers the starter motor (load) to keep the engine running.

A major type of power system is the electrical Grid.

What is the Electrical Grid?

The conventional power system that is known to almost everyone is the electrical Grid. An electrical grid, also known as a power grid, is a power system network which consists of generating stations, transmission line, distribution lines and consumer loads.

The electrical grid system can be centralised or decentralised.

In the decentralised electrical grid, power is generated in locations, most times, close to consumers, and distributed through distribution lines to consumers. Many of the energy sources for decentralised electrical grid are from renewable energy. Examples are mini-grid, mini-hydro, solar power system (with solar panels on roofs), etc.

In the centralised electrical grid system, Power is generated, most times, in locations far from consumers; transmitted through high power lines and then distributed through distribution lines to the consumers.

The power that is generated in a different locations might be through different means.

How power can be generated in centralised electrical grid

Basically, power can be generated using generators. Now, generators come in different sizes and capacities. Like, the generators used in homes, hospitals, schools, etc are small generators. Also, solar panels are another type of generator.

The generators that are used in the centralised electrical grid are always of high capacity and size. It does not compare with the home-based ones, as it comes with various other components to help it generate power.

In a centralised electrical grid, the units that generate power is the power generating stations. The different types of power generating stations in existence are Hydro, nuclear, gas, and thermal generation stations, Wind, large solar farms and so on.

Basically, in the hydro, nuclear, gas and thermal generating stations, the turbine shaft is connected to the rotor of the generator. So, as the turbine rotates, the rotor of the generator also rotates, thereby leading to the generation of electricity.

The energy required to drive the turbine in individual generating stations varies. For hydro generating stations, energy from water is required to drive the turbine. While for gas generating stations, energy from natural gas is required to drive the turbine.

In the wind power generating station, the wind drives the wind turbine which in turn drives a generator to generate electricity.

The large solar farms make use of solar panels to convert solar radiation to electricity.

From the generation station, power is generated at a certain voltage; stepped up to a higher voltage through substations (containing step-up transformers and other components); and fed to the power transmission network.

The role of power transmission?

The power transmission integrates the power from various power generating stations and transmits it (at extra-high voltage) through power lines (transmission network) to a transmission substation where it is stepped down to high voltage.

The transmitted power whose voltage has been stepped down is then transmitted to a power distribution substation.

In essence, Power transmission transmits power in Bulk, and at a very high voltage.

The role of the Power distribution unit?

The power distribution helps deliver power to the final consumer.

At the power distribution substation (which contains a step-down transformer and other accessories), the voltage of the transmitted power is stepped down to a medium voltage.

Even though the voltage of the transmitted power has been stepped down, it still can’t be used by consumers. So, it is distributed to other substations which can step down the voltage to a consumer-friendly voltage. This substation is what we find around our neighborhood.

From the substation, power is then distributed to the consumers.

Who are the electric power consumers?

It should probably be ‘what’

Power consumers are not humans, they are the electrical appliances or loads humans use.

There are three major types of consumers: Industrial (Businesses that deal in manufacturing), commercial (businesses that deals in selling) and residential consumers (homeowners).

They all make use of different machines and appliances that consumes power. The common consumers of electric power are light bulbs, electronics, motors (can be found in fans too) and so many others.

The electrical grid power system could differ from country to country, but they follow the same ideology.