Municipal projects, such as rail transit, sewage treatment, telecommunications, heat, gas, etc. Computers, air conditioners, chillers, energy-saving lamps, UPS power supplies, LED screens, and inverter-type power loads are the main sources of harmonics.

1. Computers and computers are not only necessary equipment for every office worker, but also an important home entertainment device. Single-phase rectification (ie. 4-pulse rectification) is commonly used in electronic equipment. The number of harmonics generated is an integer multiple of the pulse wave number ± 1, that is, the 3rd, 5th, 7th, and 9th harmonics. Harmonic content is about 15%~20%

2.Air conditioning machine. The harmonic distribution is 2 to 15 times. The magnitude of the harmonic current varies depending on the mode of operation. When the fan is turned on, the harmonic current is about 10%, the harmonic current is about 25% during cooling, and the harmonic current is about 30% when heating.

3. Energy-saving lamps. Energy-saving lamps are almost all harmonic sources. The harmonic currents of most energy-saving lamps are distorted. Due to design differences, the harmonic currents of different types and models of energy-saving lamps are different, generally 15%-20%.

4. The inverter. Its harmonic content is about 40%.

1. Centralized management: DBL-AP7/ATP7 series reactive power compensation device + DBL-APF series active filter

Terminal local management: DBL-PQ terminal power quality device + DBL-NP series neutral line security energy-saving device

2. Centralized management: DBL-AP7/ATP7 series reactive power compensation device + DBL-SVG static var generator + DBL-APF series active filter (DBL-AP7/ATP7 mixed with SVG)

Terminal local management: DBL-PQ terminal power quality device + DBL-NP series neutral line security energy-saving device

3.Centralized management: DBL-SVG static var generator + DBL-APF series active filter

Terminal local management: DBL-PQ terminal power quality device + DBL-NP series neutral line security energy-saving device