Interference in the power supply is preventing or impairing reception of signals. The sources of such obstacles can be not only external, but also internal factors. Understanding and understanding the root causes of this phenomenon will avoid many problems, and will also help in the selection and placement of equipment. Therefore, before proceeding with the elimination of interference in the network, you need to know how to remove them and what sources of occurrence exist.
Content:
- Interference classification
- Protection methods
- Measurement methods
Interference classification
There are two types of interference in the electrical network: impulse and high frequency. The first ones arise when the device is turned on or off in the mains. They are dangerous, as they can disable all electronic equipment in the house in a short time. High-frequency interference always exists on the network, but it is not considered as dangerous as impulse interference.
The causes of the phenomenon:
- voltage fluctuations and deviations;
- impulse voltages;
- harmonics;
- frequency deviations;
- short voltage dips.
An electrical network in which there is interference can be subject to voltage deflection and fluctuations. Learn more about what are voltage drops and how to protect yourself from them, you can from our article.
The electrical network is also exposed to impulse voltages. The reason may be natural phenomena in the form of thunderstorms or switching operations that are carried out in the network.
Multiple harmonics are sinusoidal current or voltage. The difference in the frequency of such a phenomenon will differ many times from the fundamental frequency. If the power grid has a non-linear current-voltage characteristic, then this type of interference occurs. Main sources: TVs, fluorescent lamps, conversion units, induction furnaces.
An electrical network with a multiple harmonic can be connected to the transformer through static frequency converters. The frequency and duration of harmonics will depend on the output frequency of the inverter.
Frequency deviation occurs due to the fact that the power of the generators that generate electricity does not match the consumed load. The grid, which increases the load power, increases the frequency and speed of the generator.
If the electrical network receives an unexpected and sharp decrease in voltage, then this means that such an interference has arisen as short voltage dips. The power grid will resume normal operation after a certain period of time. This phenomenon occurs in power systems due to switching processes that are associated with the starting and operation of high-power motors, and are also associated with a short circuit.
Consumers must take into account the fact that it is impossible to eliminate or reduce the amount of interference that is generated by the operation of power systems to eliminate short circuits.
Protection methods
Interference in the electrical network can occur at any time, which will lead to unpleasant moments and losses. For example, if you work at a computer, important text data may disappear. To avoid this, protection from such phenomena is necessary.
An excellent solution in this case would be protection with an uninterruptible power supply (UPS). After the mains has been disconnected, the battery remains operational for at least ten minutes. This will be enough to save all important documents and programs. Also, such a power source serves as protection against voltage surges. About, how to choose an uninterruptible power supply, we talked about in a separate article.
Protection against interference in the network can be carried out in a cheaper way: the use of line filters. Such a device will be able to save devices that are connected to the mains from power outages and interference. Protection in such ways will allow you to protect devices and interference in the network will be harmless to them.
Measurement methods
Measurement of noise in the network is carried out with special devices. But if there are no such devices, then additional specific measures should be applied.
Typically, an instrument that needs to measure mains noise will be powered from the same source that needs to be measured. If the wires are connected incorrectly, then there will be errors when taking readings. The figure below shows the connection diagram of the device with which the measurement will be carried out:
An oscilloscope is also used to measure interference. In the presence of a storage tube, the device will be able to make a measurement. About, how to use an oscilloscope we talked about it in a separate publication.
Finally, we recommend watching a useful video on the topic:
Now you know what causes power disturbances and how to protect yourself from them. We hope the information provided was useful to you!
You probably don't know:
- Low voltage in the network - where to complain
- How to protect the cable from damage
- Errors in the installation of electrical wiring
