Our Electric Grid – Electrical Generation Basics

Last blog I shared some basic information about the power grid, which I will expand on later. So for this blog post, I would like to share some basic information about how power is generated, which I will also expand on.

Electricity is created by energy transformation – we are taking one form of energy (chemical, nuclear, kinetic, wind, or electromagnetic radiation) and converting it into the electrical form of energy. The majority of power generation in our country is through the use of a Steam Cycle – Coal, oil, nuclear, natural gas, and others all use steam cycles. Steam systems are actually extremely complex, and very precise, but from the high level view a steam cycle uses a system of components to convert the fuel source into heat, which is intern used to heat up water and convert it into steam. The energy in the steam is then directed through a turbine, which provides kinetic energy to the electrical generator through the attached rotating shaft. The steam is exhausted from the turbine and condensed back to water for reuse. See the image below for a simplified example:

SteamCycle1

Electricity is a unique, interesting energy source. It is closely related to magnetism, and can be generated through the use of magnetism – simply passing a magnetic field by an electrical conductor, such as a piece of copper wire, will induce a voltage in the wire as the magnetic field passes it. The voltage is only induced as the magnetic field is moving, and ‘cutting’ through the wire. On the other side of that principle, when current is passing through a conductor will actually create a magnetic field. Electromagnets are created by coiling copper wire and passing electric current through the wire. These principle are how we generate electricity in our generators. In most generators, the rotating portion is just a big electromagnet, and around the armature is a bunch of coils of wire. Therefore, as the steam rotates the turbine shaft, it rotates the electromagnet causing the magnetic field to ‘cut’ the wires and induces a voltage – electricity!  This is a simpler drawing of a 1 phase generator:

AC Gen1

Power plants actually generate electricity in 3 phases, without getting in too deep yet, just consider it as 3 different power lines from 1 generator:

generatoranimation

In reality, these systems are much, much more complex, but I’m sparing the details for some more advanced blogs later, but I’ll share a little bit for future topics. The generation systems have to maintain a certain voltage output, and frequency, otherwise it would damage our electronic devices. Therefore, there are a lot of additional monitoring systems, protective systems, and regulation systems – the turbine speed is regulated to maintain generation frequency, and the electromagnetic field is also regulated to maintain the voltage output of the generator.

For next week I will be discussing how the different fuel sources get broken down and used to create heat, and I’ll also discuss a microcontroller project I’m currently working on using an Arduino Mega – Follow my blog and stay tuned for more!

2 thoughts on “Our Electric Grid – Electrical Generation Basics

  1. Pingback: John Kitchen

  2. Pingback: Our Electric Grid – Renewable Energy Sources, Part 1 | John Kitchen

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