What is harmonic distortion and why is it a problem?

Harmonic distortion happens in electric power systems whenever electricity is converted from AC to DC by devices classified as non-linear loads. The interaction between your AC power and non-linear loads causes the original AC signal to be distorted and deliver less power than it should. Most modern devices we use nowadays such as LED lights, computers, TVs, etc. are actually non-linear loads and make harmonic distortion a problem for most electrical systems.

Why do we convert AC to DC?

Voltage (electrical potential energy) and electric current (moving electrons) are what provide power to an electrical circuit. In the late 1800s, the electricity giants Thomas Edison and Nicola Tesla went to war with each other over which kind of electricity would power the world, direct current or alternating current. Edison's direct current (DC) moves electric current in one direction on a circuit with a constant voltage level. In contrast, Tesla's alternating current (AC) switches the direction of voltage a certain number of times per second. In the graphs below, you see how the applied voltage either stays the same or changes over time for DC and AC. 

It turned out that AC power was easier to transmit over long distances, so it became standard for power companies to send power to homes and businesses in the U.S. with 60hz AC (sixty times a second). Most modern electronic devices, however, run on DC power since it is more suited for storage in batteries and is handled better by sensitive circuit boards. The alternating current provided by your power company is converted to direct current by those devices so they can run as designed. 

How is my AC power distorted?

When your power company transmits electric power, they want your alternating current to be as "pure" as possible and switching direction in a consistent way. AC that cleanly changes voltage at the standard 60hz frequency is the most effective at delivering power. 

What perfect AC would look like

Most modern electronic devices are non-linear loads. Whenever they convert the AC voltage to DC, they introduce higher frequencies called harmonics back into the original AC waveform. 

Harmonic frequencies added to your AC by non-linear loads

When you add up all the extra harmonics caused by non-linear loads, your AC voltage gets distorted and no longer behaves like the "pure" 60hz transmitted by your power company. We call this harmonic distortion.

What your AC looks like with harmonic distortion

 

How does harmonic distortion affect me?

So why do you care if your AC voltage gets more wonky whenever you plug in your electronics into the wall? Let's revisit how power is generated to answer that.

Power = voltage x current

The power that your devices need is dependent on the amount of voltage and current that they experience. Increase either voltage or current and the delivered power goes up. Decrease either of them and the delivered power will also decrease. The bad thing about harmonic distortion is that it decreases the average voltage level. So what do your devices have to do in order to get the power they need when there is less voltage? They draw more electrical current. 

When your devices draw more electric current, the additional electrons coursing through their circuits causes them to heat up more than usual and wear down faster. If you manage a lot of electronics, harmonic distortion increases your maintenance and replacement costs. The extra current also means that you'll have to pay for more electricity and see higher electric bills from your power company. 

What can I do about it?

That's where we come in.

Here at Atalon Green, we specialize in providing electrical filters that are specifically designed to get rid of the harmonic distortion in your AC power. Homeowners are saving on their monthly electric bill and businesses are seeing the benefits of reduced maintenance costs on top of their monthly energy savings. 

You can checkout our other resources to learn more about electrical filters or you can get started on your journey with us to save the planet, your devices, and your wallet.