Practical knowledge | Briefly describe the hazards of harmonic generation and solutions for harmonic control
What is harmonic?
Harmonics refer to the amount of electricity contained in a current with a frequency that is an integer multiple of the fundamental frequency. Generally, it refers to the Fourier series decomposition of periodic non sinusoidal electricity. In addition to the electricity at the fundamental frequency, the electricity at currents with frequencies greater than the fundamental frequency is called harmonics.
The harmonic frequency is the ratio of the harmonic frequency to the fundamental frequency.
Source of harmonics
At present, electrical equipment is diverse and complex, and the nonlinearity of loads is becoming increasingly common, causing a harsh harmonic environment and posing a great threat to ensuring the safe and normal operation of power systems and equipment.
Among them are air conditioning, water pumps, fans, elevators, computer room network equipment, office equipment, UPS, lighting control systems, fire protection systems, monitoring systems, and other power electronic devices.
What are the hazards of harmonics?
What are the benefits of treating harmonics?
Direct benefits: 1. Protect capacitors from interference, 2. Reduce losses, 3. Reduce heating of lines and busbars; 4. Protect electrical equipment
Indirect benefits: Improve the quality of system electrical energy, reduce the capacity burden of the distribution system, and protect the safe and stable operation of electrical equipment.
Social benefits: Eliminating harmonics from the source of every low-voltage harmonic source, preventing harmonic currents from flowing into the higher-level power grid, and contributing to the construction of a perfect power quality power grid
What standards does harmonic follow?
National standard: GB-T14549-1993 "Harmonics in Power Quality Public Grid" was first promulgated in 1993, and in 2011, standards for the mechanical and communication industries were successively issued: "JB11067-2011T Low Voltage Active Power Filter Device" and "YDT2323-2011_Low Voltage Parallel Active Power Filter for Communication"
How to control harmonics?
Haoan Electric's customer has developed Haoanet active power filter APF to address harmonic issues. Haoanet APF modular design includes rack mounted and wall mounted models. Adopting modern power electronics technology, intelligent control, and fast dynamic compensation for harmonics of any order; Simultaneously possessing functions of harmonic compensation, reactive power compensation, and imbalance compensation.
After compensating for the 2nd to 50th harmonics through Haoanet, the THDi is less than 5% and the cos is 0.99 level compensation effect.
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