The growing demand for high-precision sensing technologies in power systems has po-sitioned the development of novel electric field measurement tools as a critical metro-logical challenge. This study presents a broadband photoelectric electric field sensor based on the Mach-Zehnder interference phenomenon in asymmetric straight wave-guides. Furthermore, a three-dimensional electric field measurement system was de-veloped through systematic investigation of multidimensional field measurement methodologies. Experimental results demonstrate that the proposed device achieves broadband electric field measurement with linearity up to 0.9996 and pow-er-frequency measurement accuracy exceeding 97%. The system demonstrates con-current measurement capability for both lightning impulse waveforms and operation-al power frequency electric fields. The synthesized three-dimensional measurement error remains below 4%, enabling precise omnidirectional electric field detection.

To achieve the broadband applicability of standard voltage transformers in “dual high” power systems, an equivalent circuit model of the standard voltage transformer is first established. Using the complex magnetic permeability method and utilizing existing core parameters, the excitation impedance values are obtained. Next, based on the equivalent circuit model, the no-load error function of the standard voltage transformer is analyzed, and through simulation, the no-load error response curve of the standard voltage transformer in the frequency range of 20 Hz to 3000 Hz is derived. The simulation results indicate that within the 20 Hz to 700 Hz range, both the no-load ratio error and the no-load angular error meet the accuracy requirements, with the ratio error within ±0.05% and the angular error within 2′. Additionally, the derivation of the error transfer function demonstrates the correlation between the no-load error values and the number of turns and cross-sectional area of the standard voltage transformer. Simulation results, obtained by increasing and decreasing the number of turns and cross-sectional area by 10%, provide valuable insights for the error compensation and structural design of standard voltage transformers.

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.

Current measurement in Power and Energy Systems must accommodate direct-current components, converter harmonics, fast transients, wide dynamic ranges, and strong electromagnetic interference. Tunneling magnetoresistance (TMR) sensors offer high field sensitivity, broad intrinsic bandwidth, compact size, and low power consumption, but these device-level advantages do not directly translate into system-level accuracy or usable bandwidth. The principal contribution of this review is a unified framework organized around sensor architecture that connects magnetic tunnel junction transfer characteristics and Wheatstone-bridge behavior to complete current-sensing systems. Unlike previous reviews organized mainly by materials, operating principles, or applications, this work compares surface-mounted, linear-array, ring-array, and magnetic-core open- or closed-loop architectures across sensor-element, circuit, external-field, manufacturing, and installation errors, together with compensation strategies, test conditions, implementation burden, and application evidence. It further distinguishes device metrics from complete-system performance and laboratory feasibility from deployment evidence. The comparative analysis identifies current-to-field geometry, bridge matching, thermal drift, external interference, signal conditioning, and feedback dynamics as the coupled factors that determine usable range, accuracy, and bandwidth. Their relative importance changes with architecture: surface-mounted layouts are especially sensitive to placement and crosstalk; linear and ring arrays introduce channel-matching and spatial-calibration requirements; and magnetic-core designs are additionally constrained by core behavior and, in closed-loop systems, feedback dynamics. These relationships provide a requirements-driven basis for selecting an architecture according to waveform, current range, installation geometry, interference environment, and uncertainty requirements. Meaningful comparison further requires common-condition evaluation of amplitude and phase error, overload recovery, environmental stability, and calibration transfer across devices and installations.