High-voltage electric field measurement technology has certain applications in electric field measurement of power systems, but due to the limitation of its measurement accuracy and bandwidth, it cannot be used for the measurement of lightning-impulse voltage. In order to calibrate the nonlinearity of the MV-level lightning-impulse voltage measurement system, this paper proposes the design and implementation of a high-precision inductive wideband electric field measuring sensor (EFMS). The influence of the metal shell on the electric field distribution was simulated, and the influence of the electric field non-uniformity coefficient was studied. The characteristics of the EFMS were tested, and the results showed that the EFMS can accurately reproduce the waveform of lightning-impulse voltage and power-frequency voltage, with a proportionality coefficient of 0.05664 V/(kV/m). In mostly uniform and extremely non-uniform fields, the nonlinearity of the EFMS for impulse voltage is less than ±0.25%, and the nonlinearity of the EFMS for power-frequency voltage is less than 0.1%. It is shown that the EFMS can be used for the nonlinearity calibration of ultra-high voltage impulse measurement devices.

To ensure the evaluation uniformity of the values of impulse voltage parameters, a method for determining the scale factor of impulse voltage measurement or a generation system based on multifrequency component synthesis in the energy domain is proposed. According to Parseval’s theorem, a functional relationship between the impulse scale factor and the ac scale factors is established for the impulse voltage measuring device. The challenge of accurately obtaining the scale factor for the measuring device under aperiodic instantaneous pulse waveforms is transformed into two problems: obtaining the scale factor for the periodic alternating voltage of different frequencies and calculating the weight of each frequency band. At the same time, the systematic errors introduced by approximation and segmentation during the process of converting mathematical models into measurement models are analyzed. Finally, a specific implementation method based on this evaluation method is proposed. An experimental verification of the impulse scale factors was conducted separately for a digital recorder and an impulse voltage divider. The results showed that the proposed method can accurately assess the scale factors of impulse voltage measuring devices, with feasibility and operability in metrological practices. The extended uncertainty of the impulse voltage scale factor obtained through this method is 0.02%. Furthermore, the evaluation method is universal; therefore, theoretically, any impulse voltage that can be represented with a mathematical function can be decomposed and evaluated for scale factors using this method.

Magnetic-core current transformers (CTs) are susceptible to high-frequency resonance during nanosecond-scale pulsed current measurements due to distributed parasitic elements, resulting in limited bandwidth and reduced accuracy. To address this issue, an optimized design approach based on segmented damping resistors is proposed. A PCB-based coplanar interwound structure is further introduced into a conventional magnetic-core CT with self-integration to enable precise damping configuration and reduce parasitic inductance, supporting the development of dynamic damping networks. Meanwhile, a distributed-parameter equivalent circuit model incorporating parasitic effects is constructed to elucidate the resonance suppression mechanism, where theoretical analysis establishes the relationship between segmentation and oscillation attenuation, and Simulink simulations are conducted to evaluate output behavior under varying segment counts. Furthermore, experimental tests using a square-wave excitation with a 20 ns rise time are carried out to compare undamped and segmented damping configurations, showing that high-frequency oscillations are effectively suppressed, with damping performance improving as the segment number increases. In particular, a 13-segment configuration reduces overshoot to 19.7%, achieving a 72.9% decrease compared to the undamped case. These results verify the effectiveness of segmented damping in mitigating high-frequency parasitic effects and offer a theoretical and engineering basis for the precision design of fast pulsed current measurement systems.

High-voltage and high-current impulse waveforms, characterized by a diverse frequency spectrum, pose challenges for accurate traceability to national standards. Traditional methods for tracing impulse quantities to a single-frequency measurement standard are not universally applicable. This paper introduces a novel approach that establishes a general traceability method by mapping the impulse scale factor to a multi-frequency AC scale factor based on the energy spectrum, enabling indirect traceability to the power frequency standard under high-voltage or high-current conditions. A full-waveform inversion method is employed that integrates the frequency spectrum of measured impulse waveforms using fast Fourier transform (FFT) with the frequency response characteristics of the measuring system, which are determined through convolution based on square wave responses. This approach facilitates traceability of time parameters for arbitrary impulse waveforms. Experimental results demonstrate that the resistive impulse voltage divider's scale factor uncertainties at low and high voltages are 3.100×10^-4 and 1.344×10^-3, respectively. Additionally, the uncertainties for the T₁ and T₂ parameters of the inverted waveform of the attenuator are within 0.45% and 0.03%, respectively. These findings validate the effectiveness of our traceability theory.

The synthetic model of the impulse scale factor is the foundation for tracing impulse waveform peaks to AC measurement standards. However, existing research has primarily focused on double-exponential 1.2/50 μs impulse waveforms, while for 8/20 μs impulse current waveforms—characterized as exponentially damped sinusoidal oscillations with pronounced spectral broadening and oscillatory features—conventional models fail to provide accurate characterization, leading to significantly increased synthetic errors. Based on Fourier transform theory, this study derives a multi-parameter mapping relationship between the impulse scale factor and AC scale factors. A fractional-order error suppression method and frequency band optimization strategy are proposed, establishing a synthetic impulse scale factor model suitable for 8/20 μs waveforms that significantly extends the applicability of existing models. Simulation results demonstrate that with the fractional-order parameter z = 0.1, the relative error of μ decreases by a factor of 12 times compared to existing models; meanwhile, the optimized frequency band division reduces data acquisition workload by 39% while maintaining measurement accuracy. This research defines the applicability boundaries of scale factor synthetic models under 8/20 μs impulse waveforms, providing theoretical support and practically efficient modeling methods for the traceability of impulse peak values.

Impulse current measurement technology is widely used in various applications, including lightning protection monitoring in power systems, welding current measurement in aircraft and shipbuilding industries, as well as high-current measurement in pulsed power systems. With the advancement of industrial technology, the measurement range of impulse currents has continuously expanded, reaching levels as high as mega-amperes (MA). The calibration of the scale factor for impulse current measurement devices is determined through comparison with standard measurement devices. Developing high-accuracy impulse current measurement devices and accurately judging their characteristics are prerequisites for ensuring the precise calibration of impulse current values. This paper introduces two different types of high-impulse current measurement devices. Experimental studies were conducted on the scale factor and response characteristics of the sensors. The scale factor extension calibration method for sensors under high currents of more than 100 kA has also been introduced. Test results indicate that the developed impulse current measurement devices can serve as standard measurement devices for high impulse current measurement.