Lighting surge analysis and how does it work

The SG61000-5 fully automatic surge generator (also called lightning surge immunity test, combination wave generator, surge current generator/surge voltage generator, combined surge voltage and current generator) .

How does a surge generator work?
The SG61000-5 surge generator provides a common basis for evaluating the resistance of power cords and internal connectors of different equipment to high energy transient interference caused by natural lightning surge induction and large capacity load switching. It fully meets the IEC 61000-4-5, EN61000-4-5 and GB/T17626.5 standards.

The common electronic equipment damage are not caused by lightning strikes directly, but by the current surges induced in power and communication lines when lightning strikes occur. On the one hand, due to the highly integrated internal structure of electronic equipment (VLSI chip), the withstand voltage level and over-current resistance of the equipment is reduced; in the other hand, the withstand lightning ability(including induced lightning and operating over-voltage surge) is reduced, In the other hand, due to the number of signal source paths increases, and the system is more vulnerable to the intrusion of lightning waves than before. Surge voltage can enter computer equipment from power lines or signal lines, etc., resulting in the formation of lightning surges and damage to computer equipment and other electronic/electrical equipment.

1. Power surge
Power surges are not only caused by lightning strikes. Power surges will occur when a short circuit fault occurs in the power system or when a large load is switched. The power grid stretches for thousands of miles, and the probability of lightning strikes or line surges is very high. When a lightning strike occurs hundreds of kilometers away from you, the lightning surge is transmitted through the power grid at the speed of light, and attenuated by substations, etc., and there may still be thousands of volts when it reaches your computer. This high voltage is very short, only tens to hundreds. Microseconds, or not enough to burn the computer, but it does great damage to the semiconductor components inside the computer, just as the noise of the old sound is bigger than the new one because the internal components are damaged, as the damage deepens, the computer It also gradually becomes more and more unstable, or may cause the loss of your important data. Such a surge voltage is completely likely to damage electronic equipment at one time, so the insulation performance is good, and the high-throughput ceramic gas discharge tube with high insulation resistance and low capacitance characteristics has become the first choice for power lightning surge protection.

2. Signal system surge
The main sources of surge voltage in signaling systems are induced lightning strikes, electromagnetic interference, radio interference, and electrostatic interference. Metal objects (such as telephone lines) are affected by these interference signals, which will cause bit errors in the data in transmission, affecting the accuracy and transmission rate of transmission. Removing these interferences will improve the transmission of the network.

The picture above is a pulse generation circuit that simulates the surge voltage induced in the transmission line when the lightning strikes the power distribution equipment, or the counter high voltage generated by the lightning current through the common ground resistance after the lightning strikes. The single pulse energy at 4kV is 100 joules. In the figure, Cs is the energy storage capacitor (about 10uF, which is equivalent to the thundercloud capacitor);
Us is high voltage power supply;
Rc is the charging resistance;
Rs is the resistance formed by the pulse duration (resistance formed by the discharge curve);
Rm is the impedance matching resistor Ls forms the inductance for the current rise. The lightning surge immunity test has different parameter requirements for different products. The parameters in the above figure can be slightly modified according to the product standard requirements.

For the test on the power line, it is all done through the coupling and decoupling network. There are two modes of coupling:
Common mode
Coupling interference between L or N and PE, this is usually 2Ω
L – PE
N – PE

Difference mode
Coupling interference between the L and N, this impedance is usually 12Ω
L – N

The severity level of lightning surge immunity test is divided into 5 levels:
Level 1: better protected environment;
Level 2: Environment with certain protection;
Level 3: Ordinary electromagnetic disturbance environment, no special installation requirements for equipment, such as industrial workplaces;
Level 4: Severely harassed environments, such as civil empty overhead lines, unprotected high-voltage substations; Level X: Determined by negotiation between the user and the manufacturer;
Class X: Determined by the user in consultation with the manufacturer

Lisun Instruments Limited was found by LISUN GROUP in 2003. LISUN quality system has been strictly certified by ISO9001:2015. As a CIE Membership, LISUN products are designed based on CIE, IEC and other international or national standards. All products passed CE certificate and authenticated by the third party lab.

Our main products are Goniophotometer, Integrating Sphere, Spectroradiometer, Surge Generator, ESD Simulator Guns, EMI Receiver, EMC Test Equipment, Electrical Safety Tester, Environmental Chamber, Temperature Chamber, Climate Chamber, Thermal Chamber, Salt Spray Test, Dust Test Chamber, Waterproof Test, RoHS Test (EDXRF), Glow Wire Test and Needle Flame Test.

Please feel free to contact us if you need any support.
Tech Dep: Service@Lisungroup.com, Cell/WhatsApp:+8615317907381
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Tags：SG61000-5