Measuring the Surge Immunity of Electrical Systems: An Exploration of Surge Immunity Testing

In our lives, powerful currents are generated due to lightning strikes or sudden closing of large power station switches, which can cause great damage to our electrical equipment. Therefore, we usually use surge immunity to simulate such situations and carry out tests to protect electrical equipment as much as possible.

LISUN 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.

I. Features of Surge Immunity
1. The instrument adopts color liquid crystal touch screen display, the data is clear and obvious, easy for operators to operate, and the built-in computer control realizes intelligent operation of man-machine dialogue, which is convenient and simple, bringing great convenience to operators;
2. Program-controlled high-voltage power supply is used to make the voltage stable with high accuracy, and the current and voltage breakdown can be seen on the display screen;
3. In order to ensure the consistency of surge waveform, imported non-inductive high-power resistors are used, which greatly enhances the reliability of tests;
4. The polarity of the instrument’s voltage will be switched automatically during the measurement process, and can also be switched alternately between positive and negative poles according to the user’s test requirements;
5.The entire lightning surge anti-interference test is controlled by software, without manual operation, which greatly reduces labor loss and avoids human errors, making the test more accurate and reliable;
6. Surge injection phase angle can be arbitrarily set between 0-360 degrees to enhance the flexibility of the instrument and meet the needs of more users;
7. The instrument is equipped with current and voltage attenuator, which can be connected directly to oscilloscope through BNC to observe waveform intuitively;
8. The instrument is equipped with computer interface, which can realize remote control, and can also choose control and control system software to meet the needs of more users.

Surge Generator SG61000 5 

II. The simulated situations of Surge Immunity Test mainly simulate various situations caused by indirect lightning strike
1. When lightning strikes external lines, a lot of current flows into external lines or grounding resistance, thus generating interference voltage.
2. Indirect lightning (such as lightning between clouds or within clouds) induces voltage and current on external lines.
3. When lightning strikes nearby objects, the strong electromagnetic field established around it induces voltage on external lines.
4. When lightning strikes the ground near the ground surface, the interference caused by the earth current passing through the public grounding system. In addition to simulating lightning strikes, scenarios in power plants such as substations are simulated, such as interference caused by switch action (voltage change due to switching), such as:
1). Interference caused by switching of main power supply system (such as switching of capacitor group);
2). Interference caused by small switches jumping near the equipment;
3). Switching of thyristor equipment accompanied by resonance line;
4). Various systemic faults, such as short circuits and arc faults between device grounding networks or grounding systems.

III. Matters needing attention for Surge Immunity
1. Operators must be trained and studied before they can operate the equipment, and the user manual should be read before operation;
2. Pay attention to the model and wiring mode before and after power on and off;
3. The instrument should be grounded well;
4. The panel indication value should not exceed 4.5kV when setting high voltage, and do not touch the interfering circuit with your hands;
5. The instrument should not be reversed to prevent vibration;
6. In order to ensure the comparability and repeatability of the test, the test configuration must be standardized;

IV. Sources of surge voltage caused by lightning
1. Direct lightning acting on external circuits, injecting large current flowing through grounding resistance or external circuit impedance to generate voltage;
2. Indirect lightning (induced voltage and current) on internal and external conductors of buildings;
3. Lightning current to ground near to the equipment coupled to the common grounding circuit in the power system grounding network. When the protective device acts, the voltage and current may change rapidly and may couple to the internal circuit.

V. Advantages of Lightning Surge Immunity
1. Large LCD display, computer control, one-time setting, automatic completion of test items.
2. Intelligently collect breakdown voltage value of the specimen during the test, which is displayed directly on the LCD.
3. Programmable high-voltage power supply, high voltage stability and accuracy.
4. Imported electronic main switch, stable waveform, strong comparability and long service life.
5. Negative and positive can be automatically switched, and positive and negative polarities can be switched alternately.
6. Surge injection phase angle 0-360° can be set arbitrarily.
7. Built-in four test levels according to IEC61000-4-5.
8. Built-in current and voltage probe, BNC connected to oscilloscope to observe the waveform (optional).
9. EMCK3000 measurement software saves waveforms and test records (optional).
10. RS-232 communication interface, can realize remote control, and optional control system software.

VI. Results of Lightning Surge Immunity Test
1. Normal performance within the limits specified by manufacturer, entrusting Party or purchasing Party;
2. Temporary loss or reduction of function or performance, but can recover itself after interference stops, without the intervention of operator;
3. Temporary loss or reduction of function or performance, but need the intervention of operator to recover;
4. Unrecoverable loss of function or performance due to hardware or software damage of equipment, or data loss.

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.

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