Mai yadda ake kawo harmonics a cikin gwamnati na kirkiro?

Harmonics da electrical systems suna fito da nonlinear loads wadanda suka yi non-sinusoidal waveforms of current ko voltage a alternating current systems. Harmonics suna cikin sine wave components da multiples of frequencies other than fundamental frequencies. Duk da cewa mafi yawan abubuwa na harmonics a electrical systems:

Nonlinear load

Nonlinear loads suna da current da ba linearly related to the voltage. Wani wannan nau'in load ya fi shahara a power system, kuma sources mafi yawa sun hada da:

• Rectifier: Wani device da ake amfani da ita don convert alternating current to direct current, misali power adapter, frequency converter, etc.

• Switching power supply: Power supply da ake amfani da ita a modern electronic equipment, misali computer power supplies, mobile phone chargers, etc.

• Inverter: Wani device da ake amfani da ita don convert direct current to alternating current, common a solar photovoltaic systems, electric vehicle charging stations, etc.

• Variable frequency driver: wani device da ake amfani da ita don control the speed of a motor, widely used in the field of industrial automation.

• Arc welding machine: Nonlinear current an yi during the welding process.

• Gas discharge lamps: misali fluorescent lamps, high-pressure sodium lamps, etc., za su produce harmonics during start-up and operation.

Power electronic equipment

Power electronic devices widely used in modern power systems suna da muhimmanci a cikin sources of harmonics:

• Frequency converter: used to control the speed and torque of the AC motor, its working principle will produce harmonics.

• UPS (Uninterruptible Power Supply) : Harmonics an yi when switching to battery powered mode.

• Converter: Wani device da ake amfani da ita don change the frequency of alternating current, misali a converter used in wind power generation.

Motors and transformers

Akwai kuma slight harmonics zai faru a traditional motors and transformers saboda magnetic saturation effects:

• Motors: Especially in the start-up phase, harmonics may be generated due to the influence of nonlinear magnetization curves.

• Transformer: When the transformer works in the saturated area, it will also produce harmonics.

Problems with the grid itself

• Unbalanced load: An unbalanced load in a three-phase system can cause the neutral current to contain harmonics.

• Long-distance transmission: In the process of long-distance transmission, the inductance and capacitance effects of the line may lead to the amplification of harmonics.

Other factors

• Aging of power equipment: Older power equipment may produce additional harmonics due to degradation of internal components.

• Design Flaws: Poorly designed power systems can lead to amplification or generation of harmonics.

Harmonic effect

Harmonics can cause a variety of adverse effects on power systems, including but not limited to:

• Increased equipment losses: Harmonics can lead to additional losses of motors, transformers and other equipment, shortening the service life.

• Reduce system efficiency: Harmonics can reduce system efficiency and increase energy consumption.

• Affect the measurement accuracy: Harmonics will interfere with the measurement accuracy of the energy meter, resulting in incorrect calculation of electricity charges.

• Interference with the communication system: Harmonics will cause interference to the communication system and affect the quality of signal transmission.

• Triggering resonance: In some cases, harmonics can resonate with inductors and capacitors in the system, causing serious power quality problems.

Harmonic suppression measure

In order to reduce the impact of harmonics, the following measures are usually taken:

• Filters: Install passive or active filters to absorb or counteract harmonics.

• Increase the inductance of the load: By increasing the inductance of the load to suppress harmonics.

• Improve load characteristics: Use a load with low harmonic content, such as a three-phase rectifier instead of a single-phase rectifier.

• Dynamic reactive power compensation: Use equipment such as SVG (static reactive power generator) for dynamic reactive power compensation.

Sum up

Harmonics a electrical systems suna fito da nonlinear loads, misali rectifiers, switching power supplies, inverters, variable frequency drivers, etc. Harmonics can negatively affect the performance and reliability of the power system, so it is necessary to take appropriate measures to suppress or eliminate harmonics.