Test Design of Lightning Surge Immunity Test in Electronic Equipment
Date: 2025-11-13Read: 0
When lightning strikes, when electronic devices transmit along power or signal lines, the strong current and its generatedElectromagnetic PulseIt can generate overvoltage through conduction, induction, coupling, and other methods, forming lightning surges. Usually, lightning perceives high voltage on exposed power lines, which not only directly transmits to devices, but also couples electromagnetic induced surges with surrounding signal lines when the power lines conduct. This kind of surge can cause significant damage to electronic products, so products need to have a certain level of surge anti-interference ability.
The anti-interference degree of lightning surge mainly tests the anti-interference degree of electrical and electronic equipment to single pole surge (impulse) caused by switch and lightning transient overvoltage.
Establish a common benchmark to evaluate the performance of electrical and electronic equipment in surges. Usually, laboratory testing simulates the impact of lightning interference on equipment. Surge is the rapid rise and fall of current or voltage propagating along power or signal lines.
Transient of power system switches:
(1) Resonance phenomena related to switching devices such as thyristors;
(2) Distribution systems with small local switch actions or load changes;
(3) The main switching disturbances in the power system, such as capacitor switching;
(4) Equipment combination short circuit to grounding systemarc faultWaiting for various system failures.
(1) Direct lightning strike refers to the voltage generated by the high current injected into an external circuit through a grounding resistor or external circuit impedance;
(2) When coupled to the common path of the equipment combination grounding system nearby, the lightning current discharged directly to the ground nearby generates induced voltage;
(3) Indirect lightning (i.e. electromagnetic fields generated by lightning strikes between or within cloud layers or nearby objects) generates induced voltage and current on conductors inside and outside buildings.
Classification of lightning levels:
LPZ0A area: All objects within this area may be directly struck by lightning, resulting in all lightning currents; The electromagnetic field strength within the area has not decreased.
LPZ0B area: Objects within the area cannot be directly struck by lightning currents corresponding to the selected rolling ball radius, but the electromagnetic field strength within the area has not decreased.
LPZ1 zone: All objects in this zone cannot be directly struck by lightning, and the proportion of current flowing through various conductors cannot be directly struck by lightning. LPZ0B has a small area; According to the shielding measures, the electromagnetic field strength in this area may attenuate.
LPZ2 follow-up lightning protection zone: When it is necessary to further reduce the current and electromagnetic field strength, the follow-up lightning protection zone should be added, and the requirements for the follow-up lightning protection zone should be selected according to the environmental area that needs to be protected.
Experimental configuration
1. Combination wave generator, coupling/decoupling network and other auxiliary equipment.
2. The combined wave generator is divided into two types: 10/700 μ s and 1.2/50 μ s, corresponding to different port types.
3. Classification
The surge immunity test is divided into:
(1) Surge voltage immunity test (open circuit voltage)
(2) Surge current immunity test (short-circuit current)
Note: Surge anti-interference test simulates indirect lightning strikes, without considering direct lightning strikes or direct lightning strikesEUTInsulation capacity withstand high voltage test.
1.2/50 μ s waveform introduction:
1) Circuit schematic of combined wave generator
2) Specificallywaveform diagram
10/70 μ s waveform introduction:
1) Circuit schematic of combined wave generator
2) Specific waveform diagram
Scope of application for two types of surge signals:
(1) Suggest using 10/7000 communication network and long-distance signal circuit port μ s shock wave. Common electronic devices, such as RJ45, RS232, XDSL, RS485, security cameras, etc.
(2) It is recommended to use one AC/DC power port and one short distance signal circuit port for 1.2/50 μ s shock waves. Common electronic devices, such as LED lighting equipment, base stations, etc.
Common equipment port anti wave capability test
Subdivision diagram of lightning protection area:
Recommended protection level for each interface:
