High-voltage (HV) lightning impulse voltage generator test systems are critical for simulating the effects of lightning strikes and other transient overvoltages on electrical equipment. These systems ensure the reliability and safety of HV infrastructure by subjecting test objects to standardized impulse waveforms, such as the 1.2/50 μs lightning impulse defined by international standards like IEC 60060-1[citation:1][citation:8]. This article delves into the design, operation, and key considerations of these test systems, highlighting their importance in modern electrical engineering.

Components and Working Principle

A typical HV impulse test system consists of a Marx generator, front and tail resistors, a load capacitor, and measuring instruments. The Marx generator, comprising multiple capacitor stages, generates high-voltage impulses by charging capacitors in parallel and discharging them in series[citation:1]. The front resistor (R1) controls the rise time of the impulse (approximately 1.2 μs), while the tail resistor (R2) regulates the time to half-value (around 50 μs). The load capacitance (C2) includes the test object's capacitance and parasitic elements, which influence the waveform shape. Stray inductance in the circuit, often from long connecting leads, can cause oscillations or overshoot at the impulse peak, exceeding the permissible 10% limit for relative overshoot magnitude (β′)[citation:1].

Standards and Measurement Accuracy

Adherence to international standards is essential for valid test results. IEC 60060-1 outlines general test requirements, while IEC 60060-2 specifies measuring system standards[citation:3][citation:8]. Instruments like digital recorders and oscilloscopes must comply with guidelines such as IEC 61083-1 (adopted as GB/T 16896.1-2024 in China) to ensure measurement precision[citation:5][citation:10]. Accurate voltage measurement is achieved using capacitive or resistive dividers, which capture rapid transient responses. However, grounding resistance and parasitic elements can introduce errors, necessitating careful calibration and modeling[citation:4][citation:9].

Challenges and Applications

Key challenges in impulse testing include controlling overshoot and oscillations caused by circuit inductance and load capacitance[citation:1]. For instance, wind turbine blades, due to their height and exposure, require robust lightning protection tested with portable Marx generators capable of generating over 2.5 MV[citation:7]. Similarly, grounding devices are evaluated using impulse current systems producing waveforms like 8/20 μs with peak values up to 100 kA[citation:6]. Recent advancements focus on portable generators for on-site testing and improved digital measurement techniques, such as FFT-based analysis, to minimize errors[citation:7][citation:9].

Conclusion

HV lightning impulse voltage test systems are indispensable for validating the resilience of electrical equipment against transient overvoltages. By integrating standardized designs, precise measurements, and innovative solutions like portable generators, these systems support diverse applications—from energy infrastructure to aerospace—ensuring safety and performance in the face of lightning-related challenges.