Commercial buildings

Overview of power quality in commercial plazas, residential buildings, and office buildings

With the development of social economy, commercial plazas, commercial residential buildings, and public facilities are being built in large quantities. Then, in these commercial buildings and residential buildings, due to technological progress and increased demand for energy-saving lighting and inverters have been more and more widely used in the power distribution systems of these projects. However, while saving electricity, these devices also bring a lot of harmonic pollution, causing harmonic losses and safety hazards, which is called power quality pollution. Therefore, the problem of controlling harmony, improving power quality, and creating a safe, stable, efficient, and healthy green power quality environment is a very important issue in the power distribution of commercial buildings.

Power quality analysis of commercial plazas, residential buildings, and office buildings

The power harmonic pollution sources of commercial plazas, residential buildings, and office buildings are mainly generated by two aspects according to their nature: electronic ballasts and rectifier-type electronic devices. Electronic ballasts are widely used in energy-saving lighting, such as fluorescent lamps, counter downlights, etc., and the harmonics they generate are mainly 3rd and other zero-sequence harmonics. Rectifier-type power electronic devices are mainly used in UPS, office equipment, inverter air conditioners, inverter elevators and other equipment, and the harmonics they generate are mainly 5th and 7th harmonics.

Project governance solutions for commercial plazas, residential buildings, and office buildings

⚪ Choice of solutions

According to the above analysis, commercial buildings mainly generate 3rd, 5th, and 7th harmonics, but the harmonic content is not particularly large, generally reaching about 10~30%, and generally not exceeding 30%. We generally choose to install SVG for reactive compensation while being able to compensate for 2nd~13th harmonics. Compared with the active power filters + SVG/TSC solution, the SVG-only solution is more economical and more appropriate.

⚪ Harm of harmonics

• Impact on transformers

• Impact on distribution lines

• Impact on the correctness of relay protection and automatic devices

• Impact on the accuracy of metering devices