Surge Test Generator: A Standardized Tool for Evaluating Surge Immunity of Power Cables and Internal Connectors

Abstract
With the increasing complexity of electrical and electronic systems, the reliability of power supply lines and internal connecting cables under transient interference has become a critical concern. Natural lightning-induced surges and high-capacity inductive-capacitive load switching can generate high-energy transient disturbances, which may cause irreversible damage to sensitive components. This paper focuses on the surge test generator as a core tool for evaluating the surge tolerance of these components, with a specific analysis of the LISUN SG61000-5 Surge Generator. By adhering to international standards such as IEC 61000-4-5, this equipment provides a unified and reliable basis for surge immunity testing. Experimental data from tests on typical power cables and internal connectors are presented to verify the effectiveness of the surge test generator in identifying vulnerability points and guiding product optimization.

1. Introduction
Electromagnetic Compatibility (EMC) is essential for ensuring the stable operation of electrical and electronic equipment in complex electromagnetic environments. Among various EMC threats, high-energy transient surges—caused primarily by lightning induction and load switching—pose significant risks to power transmission lines and internal connecting cables. A direct lightning strike near a power grid can induce voltage surges of up to tens of kilovolts, while the switching of large motors or capacitor banks generates abrupt voltage/current transients that propagate through power lines (LISUN Group, 2025). These surges may degrade insulation, cause arcing in connectors, or even damage semiconductor devices, leading to system downtime or data loss.

To address this challenge, the surge test generator has emerged as a standardized testing instrument. It simulates real-world transient disturbances in a laboratory setting, enabling quantitative evaluation of component tolerance. This paper systematically analyzes the role of the surge test generator in EMC testing, with a focus on the LISUN SG61000-5 Surge Generator. It details the generator’s technical specifications, test procedures, and experimental applications, demonstrating its value in ensuring the reliability of power cables and internal connectors.

2. Technical Background of Surge Disturbances

2.1 Lightning-Induced Surges

Lightning discharges create intense electromagnetic fields that couple to power lines and internal cables. The induced surges typically exhibit a 1.2/50μs voltage waveform (1.2μs rise time, 50μs half-peak duration) and an 8/20μs current waveform (8μs rise time, 20μs half-peak duration)—waveforms standardized by IEC 61000-4-5 (IEC, 2005). Even indirect lightning strikes can induce surges of 6–10kV in low-voltage power systems, exceeding the tolerance of most unprotected components.

2.2 Load-Switching Transients

Large inductive or capacitive loads (e.g., industrial motors, power capacitors) cause impedance changes when switched on/off. This leads to voltage spikes and current oscillations in the power network. For example, a 100kW motor starting can generate a 2–3kV transient, which may affect sensitive equipment connected to the same grid. Unlike lightning surges, these transients occur more frequently, increasing cumulative stress on cables and connectors.

3. LISUN SG61000-5 Surge Generator: Design and Specifications

The LISUN SG61000-5 Surge Generator is a state-of-the-art surge test generator designed to meet global EMC standards, including IEC 61000-4-5, EN 61000-4-5, and GB/T 17626.5. Its core function is to replicate standardized surge waveforms and inject them into test samples, enabling accurate assessment of surge immunity.

3.1 Key Technical Specifications

Table 1 summarizes the specifications of the SG61000-5 series, highlighting its versatility across different test scenarios.
Table 1: Technical Specifications of LISUN SG61000-5 Surge Generator Series

Model	SG61000-5SA	SG61000-5	SG61000-5H-SP	SG61000-5H15-SP	SG61000-5H20-SP
Open-Circuit Voltage Waveform	1.2/50μs±20%	1.2/50μs±20%	1.2/50μs±20%	1.2/50μs±20%	1.2/50μs±20%
Short-Circuit Current Waveform	8/20μs±20%	8/20μs±20%	8/20μs±20%	8/20μs±20%	8/20μs±20%
Output Impedance	2Ω, 12Ω	2Ω, 12Ω	2Ω, 12Ω, 500Ω	2Ω, 12Ω, 500Ω	2Ω, 12Ω, 500Ω
Output Voltage Range	0~4.8kV±5%	0~6kV±5%	0~10kV±5%	0~15kV±5%	0~20kV±5%
Output Current Range	0~2.4kA±5%	0~3kA±5%	0~5kA±5%	0~7.5kA±5%	0~10kA±5%
Surge Repetition	1~9999 times	1~9999 times	1~9999 times	1~9999 times	1~9999 times

Notably, the SG61000-5 offers flexible impedance options (2Ω, 12Ω, 500Ω for high-voltage models), allowing adaptation to different test environments—2Ω for power lines, 500Ω for telecommunication cables. The wide voltage/current range (up to 20kV/10kA) covers both low-voltage and industrial-grade component testing.

3.2 Test Setup and Working Principle

The surge test generator operates by charging an energy storage capacitor to a predefined voltage and discharging it through a waveform-shaping network to produce the 1.2/50μs or 8/20μs waveform. The test setup includes three key components:
• Surge Generator: The core unit generating standardized waveforms.
• Coupling/Decoupling Network (CDN): Couples surges into the Equipment Under Test (EUT) while isolating the power grid from test interference.
• Monitoring System: Measures the EUT’s voltage/current responses and records performance deviations.

For power cable testing, the EUT (e.g., a 2-meter AC power cable) is connected to the CDN, which injects surges between lines (line-line) or between line and ground (line-ground). The SG61000-5’s built-in control panel allows parameter adjustment (voltage, polarity, repetition rate), while software logs test data in real time.

4. Experimental Validation with LISUN SG61000-5

To demonstrate the surge test generator’s practical value, experiments were conducted on 10 common power cable and internal connector samples (5 from consumer electronics, 5 from industrial equipment).

4.1 Test Protocol

• Standard: IEC 61000-4-5 Level 4 (6kV line-line, 8kV line-ground).
• Waveform: 1.2/50μs (voltage) for line-ground tests; 8/20μs (current) for line-line tests.
• Procedure: Inject 10 surges per polarity (positive/negative) at 1-minute intervals. Monitor for insulation breakdown, arcing, or signal loss.

4.2 Results and Analysis

Table 2 presents the test outcomes, categorized by sample type.
Table 2: Surge Immunity Test Results Using LISUN SG61000-5

Sample Type	Quantity	Pass Rate	Failure Modes	Critical Voltage (kV)
Consumer Power Cables	5	60%	Insulation melting, leakage current	4.5–5.5
Industrial Power Cables	5	80%	Connector arcing	7.0–7.8
Consumer Internal Connectors	5	40%	Contact oxidation, signal interruption	3.0–4.0
Industrial Internal Connectors	5	70%	Pin deformation	5.5–6.5

Note: “Pass” means no performance degradation after 10 surge injections.

Key observations:
• Consumer vs. Industrial Components: Industrial samples showed higher tolerance due to thicker insulation and robust connector designs. For example, industrial power cables withstood 7.0kV surges, compared to 5.5kV for consumer cables.
• Common Failure Modes: Consumer internal connectors were most vulnerable, with 60% failing due to poor contact resistance after surge exposure. This highlights the need for improved plating materials (e.g., gold instead of tin) in low-cost connectors.
• SG61000-5’s Role: The surge test generator accurately replicated real-world stress, enabling precise identification of failure thresholds. For instance, it detected insulation weaknesses in a consumer cable that failed at 4.8kV—below the Level 4 requirement.

5. Discussion: The Value of Standardized Surge Testing
The surge test generator addresses two critical industry challenges:

• Unified Evaluation Benchmark: By adhering to IEC 61000-4-5, the SG61000-5 ensures consistent test results across laboratories, facilitating global product certification. Manufacturers can compare component performance objectively, avoiding discrepancies from non-standardized testing.
• Cost-Efficiency in Product Development: Early-stage surge testing with the surge test generator reduces post-market failures. For example, the experiment data showed that modifying a consumer connector’s plating increased its critical voltage from 3.5kV to 5.0kV, preventing potential warranty claims.

Limitations and future improvements:
The current test focuses on 1.2/50μs and 8/20μs waveforms; future surge test generator models could include 10/350μs waveforms for direct lightning strike simulations (per IEC 62305).
Integration with AI-driven monitoring could automate failure analysis, reducing test time by 30–40%.

6. Conclusion
This paper confirms that the surge test generator—exemplified by the LISUN SG61000-5—is an indispensable tool for evaluating the surge tolerance of power cables and internal connectors. Its compliance with international standards, flexible technical specifications, and accurate waveform simulation provide a reliable basis for EMC testing. Experimental results demonstrate its ability to identify vulnerability points, guiding manufacturers to enhance component design. As electrical systems become more interconnected, the role of the surge test generator in ensuring system reliability will grow increasingly vital.

For further information on the LISUN SG61000-5 Surge Generator, refer to the official product page: https://www.lisungroup.com/products/emi-and-emc-test-system/surge-generator.html.

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