One of the most important topics in electrical engineering is harmonics. This term describes a specific type of electrical oscillation that can occur during the transmission or consumption of electrical energy.
In this article, you will learn what harmonics are, what consequences they have, and how they can be reduced.
Table of Contents
What are harmonics
Harmonics are brief peak voltages that can occur in power grids. They are caused by inductive or capacitive loads and can lead to malfunctions in electrical devices. Therefore, protective measures against harmonics are an essential part of electrical systems.
Causes of harmonics
Harmonics can be caused by various factors. The most common causes include grid disturbances, faulty components, and non-linear loads.
Grid disturbances
One of the most frequent causes of harmonics is grid disturbances. These can be triggered by various factors, such as an improperly dimensioned or disturbed circuit, voltage sags, or a power outage.
Faulty components
Harmonics can also be caused by faulty components. This is the case, for example, when a transformer is improperly dimensioned or a diode is defective. A poorly tuned power converter can also lead to harmonics.
Non-linear loads
Another common cause of harmonics is non-linear loads. These include electronic devices such as televisions, computers, or light dimmers. Motors can also act as non-linear loads, especially when operating under full load.
High-frequency devices
High-frequency devices such as mobile phones, Wi-Fi routers, or radar stations can also cause harmonics. This is particularly true when several of these devices are operated close to one another.
Consequences of harmonics
In modern power supply systems, the compensation of harmonics plays an increasingly important role. Nevertheless, the consequences of harmonics are often underestimated. They can negatively impact both technical systems and human well-being.
Harmonics can lead to increased stress on electrical and electronic components. At the same time, they can result in higher energy consumption because certain components are limited in their performance. In more severe cases, they can even cause system failures.
Human well-being can also be negatively affected by harmonics. This is especially the case when the harmonics fall into the audible frequency range. People generally react very sensitively to noise and can quickly perceive it as disturbing or even unpleasant. Even when harmonics are inaudible, their constant presence can lead to increased psychological stress.
Measures to reduce harmonics
Harmonics in the electrical power supply are a major issue. They can cause damage to equipment and cables and generally impair the power supply. Therefore, it is important to take measures to reduce harmonics. One of the most effective ways to reduce harmonics is to use filter capacitors. These capacitors are able to absorb the higher current frequencies, thereby reducing the risk of damage. Another way to reduce harmonics is to design the used equipment and cables to withstand higher peak voltages. However, this typically requires thorough planning and some knowledge of electricity to ensure the system is not overloaded. Finally, network effects can also be utilized to reduce harmonics. This includes, for example, using a common ground potential or separating phases within a network. However, these methods usually require a thorough analysis of the network and some experience in network electronics.
13 mistakes made when combating harmonics
Mistake 1: Not knowing enough about the causes of harmonics
Harmonics can occur for many different reasons. These include poor contacts, inductive interference, poor damping, and so on. To effectively combat harmonics, you must first figure out which of the aforementioned causes is responsible for the problem. Only then can you address the root cause and truly solve the issue.
Mistake 2: Taking no measures to eliminate the causes of harmonics
As already mentioned, you must first identify the causes of harmonics before you can effectively combat them. However, many companies make the mistake of taking no action to eliminate the root causes of their harmonic problems. Instead, they merely attempt to treat the symptoms of the harmonics. This is only a short-term solution and will not truly help in the long run.
3. Mistake: Taking the wrong measures to eliminate the causes of harmonics
If you decide to take measures to eliminate the causes of harmonics, it is very important that you choose the right ones. Many companies make the mistake of opting for expensive and complicated solutions instead of finding simple and effective approaches. This often results in investing a lot of time and money into something that ultimately does not really help.
4. Mistake: Forgetting to perform regular maintenance
One of the most common reasons for harmonic problems is poor maintenance. Many companies forget to carry out regular maintenance work or tend to postpone this task until the last minute. This frequently leads to certain components no longer functioning properly or being poorly maintained. As a result, serious issues can develop over time, ultimately leading to harmonic problems.
5. Mistake: Not knowing enough about harmonic protection measures
It is often assumed that simply installing a surge protector in the power grid is sufficient to protect against harmonic peak voltages. Unfortunately, this is not the case.
6. Mistake: Starting too late
Harmonics are a serious issue in electrical engineering and can cause significant damage to equipment, cables, and transformers. However, they are often not noticed immediately and therefore not addressed right away. This can be fatal, because the longer harmonics remain untreated, the more damage they can cause.
7. Mistake: Using the wrong filters
Filters are a common method for combating harmonics. However, there are different types of filters, and not all of them are equally well-suited for mitigating harmonics. Therefore, it is important to select the right type of filter for your specific application.
8. Mistake: Not enough shielding
Shielding is also an important tool in combating harmonics. However, insufficient shielding is frequently used, which can result in harmonics still being able to cause damage.
9. Mistake: No monitoring of dielectric strength
Another common source of error when dealing with harmonics is the lack of monitoring of dielectric strength. This can lead to transformers and other electrical equipment being damaged without it being noticed immediately. Therefore, it is important to regularly check the dielectric strength and make any necessary corrections if required.
10. Mistake: Do not rely on a single device
While a single filtering device can help you reduce harmonics in your power grid, it is not the only solution. If you want to take truly effective action against harmonics, you need to use multiple devices.
These include:
- High-quality power supply units
- Power filters
- Harmonic diverters
- Transient suppression diodes
11. Mistake: Do not ignore the importance of the earth
Earth is an essential component of the power grid and can be very helpful in combating harmonics. However, many people ignore the importance of earth and instead rely on more expensive and complicated solutions. If you use earth properly, you can significantly improve your power grid.
12. Mistake: Not using protective circuits
Protective circuits are very important when it comes to combating harmonics. However, many people ignore their importance and fail to use protective circuits. This is a big mistake, as protective circuits can help protect your power grid from damage.
Mistake 13: You are not using high-quality components
If you want to combat harmonics effectively, you must use high-quality components. However, many people neglect component quality and instead rely on cheaper alternatives. This is a major mistake, as high-quality components can help your power grid last longer and protect it from damage.
Conclusion
Harmonics are a serious issue in electrical engineering. Due to their complex structure, they can have both positive and negative effects on the electrical system. It is therefore important to understand and manage them precisely.
