1. Building

With the digitalization and intelligence of building construction, computers, inverter air conditioners, LED power supplies, elevators and other equipment are equipped on a large scale, introducing new power quality problems - harmonics for intelligent buildings, and a large number of nonlinear loads lead to serious distortion of voltage and current harmonics and low power factor.

Load analysis: Communication equipment, data room equipment, and special room air conditioning equipment in telecommunications buildings have very high requirements for power supply continuity, are very sensitive to voltage fluctuations, and various electromagnetic interference will affect data exchange equipment.

There are large volumes of harmonic source loads in telecommunications buildings, most of which are single-phase nonlinear loads, including:

(1) UPS power supply, large stand-alone capacity, most of the UPS uninterruptible power supply equipment with 6 pulses (3 times, 5 times, 7 times, etc.)

(2) Switching power supply, mainly used for computer and other office equipment power supply, the number is large (3 times, 5 times, 7 times, etc.)

(3) Frequency conversion air conditioners, elevators, water pumps, etc., are used in large quantities, and the frequency conversion drive equipment is the main harmonic source (5 times, 7 times, etc.)

2. TV theater stage

In TV stations, theaters, and stages, a large number of stage lighting equipment, stage machinery control rooms, air conditioning rooms, etc. will be used, which are all important harmonic sources. Moreover, these harmonics in turn affect the stage lighting effects, sound systems, etc., directly affecting the effect of the entire performance. According to the analysis, the harmonics existing in the theater TV station mainly have 3, 5, 7, 9, 11, 13 and other odd harmonics, when the load rate is 40% ~ 50% (for the normal performance of the theater, TV station common load rate), the harmonic distortion rate in the system reaches 48% ~ 53%, the harmonic content has seriously exceeded the standard, and the neutral current is too large, reaching about 150A, and the phase line current at this time is about 50A. In particular, the 3rd harmonic current generated by the lighting silicon control equipment is superimposed on the neutral line to make the neutral current too large, so that the consumption of the neutral cable increases, the heat generation increases, there is a potential safety hazard of fire, and it is easy to cause the system protection device to malfunction, causing unexplained power failure, affecting normal work.

3. Electric vehicle charging stations

As a supporting facility of electric vehicles, electric vehicle charging stations provide energy supply for the operation of electric vehicles and are an important basic support system for electric vehicles. A charger that converts AC power into DC power in the charging station charges the on-board battery of electric vehicles. The charger used in the charging (station) pile is a nonlinear device - the charger in the electric vehicle charging station generally adopts a bridge thyristor rectifier device, and the rectifier device is an important harmonic source, reducing the reliability of the power supply and distribution system, and endangering the safe operation of other electrical equipment, therefore, the electric vehicle charging station is equipped with an active power filter at the beginning of the design.

Load analysis: 6 pulse wave AC frequency conversion drive system, will produce 5, 7, 11, 13 harmonics.

Solution

The existence of power quality problems has brought serious harm to the municipality, for this reason, Bowo provides a complete set of solutions, as follows:

Application case

1. BW-APF active power filter helps the Winter Olympics