In modern power systems, the application of a large number of nonlinear loads has led to an increasing amount of harmonic content in the power grid, which seriously affects the quality of the power grid. As an important device in the power system, the harmonic suppression capability of the AC voltage regulator plays a key role in improving the quality of the power grid. This article will explore in depth the quantitative improvement of the harmonic suppression capability of the AC voltage regulator on the quality of the power grid.
Harmonics can cause distortion of the voltage and current waveforms of the power grid, resulting in a decrease in the quality of power. Specifically, it increases the loss of the power grid, reduces the efficiency of power generation, transmission and power consumption equipment, affects the normal operation of relay protection and automatic devices, and may even cause resonant overvoltage in the power system, endangering equipment insulation and system safety. For example, harmonic currents can generate additional copper and iron losses in transmission lines, increase line temperature, and shorten the service life of the line.
AC voltage regulators usually use a variety of technologies to suppress harmonics, such as filters and improved control algorithms. Filters can remove harmonics of a specific frequency from the power grid by filtering them. Some advanced AC voltage regulators also use intelligent control algorithms to monitor the harmonic content in the power grid in real time and adjust the output as needed to achieve the best harmonic suppression effect.
Total harmonic distortion is an important indicator to measure the harmonic content in the power grid. AC voltage regulator can significantly reduce the THD of grid voltage and current through effective harmonic suppression. For example, in an industrial power grid with a large number of harmonic sources, the voltage THD may be as high as 10% when AC voltage regulator is not used. After using AC voltage regulator with good harmonic suppression ability, THD can be reduced to less than 3%, making the grid voltage waveform closer to a sine wave, greatly improving the power quality.
The presence of harmonics will lead to a decrease in the power factor of the power grid and increase reactive power loss. After AC voltage regulator suppresses harmonics, it can make the waveform of the load current closer to a sine wave, thereby improving the power factor. Generally speaking, in some occasions with more nonlinear loads, the power factor may be only 0.6-0.7. Through the harmonic suppression of AC voltage regulator, the power factor can be increased to more than 0.9, reducing the transmission of reactive power and improving the transmission efficiency of the power grid.
Harmonics interact with capacitors, inductors and other components in the power grid, which may cause voltage fluctuations and flickers. AC voltage regulator can effectively reduce such voltage fluctuations and flickers by suppressing harmonics. For example, in some places with high requirements for voltage stability, such as hospitals and data centers, after using AC voltage regulator, voltage fluctuations can be controlled within ±1%, and the flicker coefficient will be greatly reduced, providing a stable power supply environment for sensitive equipment.
The harmonic suppression capability of AC voltage regulator has many quantitative improvements on the quality of the power grid. By optimizing indicators such as reducing total harmonic distortion, improving power factor, and reducing voltage fluctuations and flickers, the power quality of the power grid is effectively improved, the stable operation of the power system is guaranteed, and reliable power supply is provided for various electrical equipment, which is of great significance to improving the overall efficiency and reliability of the power system.
