AC220V 20KA Lightning Protection Solution

【Abstract】

In the wireless base station power application, the AC port of the 20KA lightning protection is a regular demand, we early use the rail type of lightning protection, due to the inconvenience of installation, more power products use on-board lightning protection, based on the above reasons, we have developed corresponding board modules, to provide convenience to customers.

【Reasons why the AC port needs to meet 20KA】

According to , the risk level of the base station is made a clear division, and the main reference factors are geographic location, lightning protection area, annual thunderstorm days, frequency of lightning strikes, stability of power supply voltage, and importance of the base station, etc., and the divisions are as follows:

1) L-type (lower risk type): downtown area, public buildings, specialized server rooms and the day of the thunderstorm is a less mined area or medium mined area.

2) M-type (medium risk type): The rooftop computer rooms of -high-rise isolated buildings in cities, suburban areas, residential buildings, water ponds, and base stations without special distribution transformers, and the thunderstorm days are medium minefields and minefields.

3) H-type (Higher Risk Type): Hills, alongside highways, farmers\' houses, paddy fields, equipment rooms prone to lightning strikes, and with multiple and strong thunderstorms on thunderstorm days (including computer rooms with overhead power lines introduced above the medium thunderstorm area).

4) T-type (Extra High Risk): High mountains, islands, and with multiple and strong thunderstorms on thunderstorm days.

Note: Base stations that are not included in the above risk types may be identified on a case-by-case basis as to the type of environment to which they belong.

The following is , the lightning protection requirements for power ports:

According to the International Telecommunication Union standard ITU-T K.56, the requirements for onboard lightning strikes are as follows:

In summary, at the AC input port, meeting the 20KA through-current capability can basically meet the application requirements of most base station power supplies.

【Onboard lightning protection solution】

Depending on the test requirements, we have two solutions:

Solution description:

A: The flat design is used, the overall height is within 19mm, but it occupies a large board area;

B: A switching type protection device is used, which can effectively reduce the residual voltage.

C: Built-in temperature release mechanism, effectively cut off the connection between the lightning protection circuit and the main circuit.

D: Electrical signal communication, photoelectric isolation, more secure for control signal;

Solution description:

A: Ultra-small size, streamlined design, more advantageous for products with space requirements;

B: A switching type protection component is used, which can effectively reduce the residual voltage;

C: TCO temperature communication;

D: In satisfies 20KA and Imax satisfies 40KA@8/20μs;

【Summary】

Both solutions have been used in a large number of customers\' products. Each has its own strengths and can be chosen according to actual needs, Bencent Electronics can also provide customized solutions for customers.

The above is our solution of 20KA onboard at the AC power port of the base station, for more protection needs, pay attention to Bencent Electronics public number.