Urban rail transit industry

Release time:

2021-04-07 10:32

sort： Industry Solutions

Application background:

The harmonic sources of urban subway traffic can be divided into two major electrical equipment:

1), high-voltage 35KV side traction rectifier inverter device generated high-order harmonics, the dominant harmonic is 11 times, 13 times, 23 times 25 times;

2) Low-voltage 0.4KV side stations, sections, depots, control centers and other large-scale use of frequency conversion fans, central air conditioners, frequency conversion elevators, electronic rectification energy-saving lamps, advertising boxes, UPS and other low-order harmonics, dominant harmonics 5, 7, 11 times.

The natural power factor of the low-voltage side is low, and the reactive power fluctuates greatly when working at full load during the day;

3) The natural power factor of the high-voltage side is high, and due to the long power supply line, there is a phenomenon of reactive reverse transmission at night under light load;

Recommended scheme:

The low-voltage 0.4KV side is directly controlled by DVG digital reactive power generator, and the high-voltage 35KV side is directly connected to the bus below 35KV by APF active filter through step-up transformer to filter out high-order harmonics, bi-directional adjustment of power factor and prevention of reactive power reverse transmission.

Design Capacity of Active Filter = Operating Current * Current Distortion Rate

Note: In order to make the compensation effect better, there is generally a margin, so the calculation capacity is generally multiplied by the 1.2 of the effective harmonic current at the maximum load rate as the final configuration capacity.

Customer Benefits:

Reduce the harmonic content to ensure the safe and stable operation of the subway power supply system;

Safety improvement of power factor to avoid fines caused by reactive power reverse;

Energy saving and consumption reduction, reduce rail transit operating costs.

Chemical industry and new energy industry

Iron and steel metallurgical industry

Chemical industry and new energy industry

Iron and steel metallurgical industry