This study aims to conduct galloping experiments using a full aeroelastic model to investigate the galloping controlling effects of interphase spacers with different kinds of arrangements on three-phase iced eight-bundled transmission lines. We designed and built a low-speed wind tunnel to assess the compact transmission lines on a single span. The similarity conditions between the aeroelastic model and the prototype were determined by the similarity theory and the proposed modification method. We considered four common arrangements of interphase spacers. Compared with the situation without interphase spacers, the composite amplitude reduction rate of the first two modes and amplitude reduction rate varying with wind speed were evaluated. Then, we investigated the anti-galloping effects of interphase spacers and analyzed the limited effects of interphase spacers on the interphase distance. Besides, the corresponding arrangements under different conditions were determined. In addition, we explored the galloping phenomena varying with wind speed. The results suggested that their galloping phenomena were changed because of the effects of interphase spacers, and coupling effects of interphase spacers with different arrangements were different. This research could be used to estimate the positions of interphase spacers and offered a theoretical foundation for the anti-galloping design of transmission lines.

In this study, the coupled ordinary differential equations for the galloping of the first two modes in iced bundled conductors, including in-plane, out-of-plane, and torsional directions, are derived. Furthermore, through numerical analysis, the critical conditions of this modal galloping are determined in the range of wind speed–sag parameters, and the galloping patterns and variation laws in different parameter spaces are analyzed. The parameter space is then divided into five regions according to the different galloping modes. Under the multimodal coupling mechanism of galloping, the impact of single and two kinds of coupled mode galloping on the spatial nonlinear behavior is explored. The results reveal that the system exhibits an elliptical orbit motion during single mode galloping, while an “8” motion pattern emerges during coupled mode galloping. Moreover, two patterns of “8” motion are displayed under different parameter spaces. This research provides a theoretical foundation for the design of transmission lines.

The theoretical results indicate that iced bundled conductors experience spatial galloping due to wind-induced vibration, involving in-plane, out-of-plane, and torsional movements. To better understand the dynamic response of this behavior from an experimental perspective, an innovative experimental method has been proposed. The method can simultaneously measure the in-plane, out-of-plane, and torsional vibration signals of iced bundled conductors’ galloping. A testing system was established, and the method is applied in the galloping experiment of continuous iced bundled conductors, validating some theoretical results. This paper describes the construction of a wide-aperture, low-speed wind tunnel suitable for testing the galloping of continuous iced bundled conductors. A ‘cut-bury-glue’ method was proposed to create a model of continuous iced bundled conductors effectively, along with a method for connecting subconductors to improve experimental precision. The tests utilized laser displacement sensors and wireless posture sensors, considering the installation and data collection characteristics of the sensors. Through signal conversion, error correction, and other technical methods, simultaneous measurement of in-plane, out-of-plane, and torsional vibration signals was achieved. The spatial galloping behavior, changing with wind speed, exhibits limited-amplitude and synchronous characteristics. The participation of different modes shows elliptical orbital motion in single-mode galloping and ‘8’ shaped orbital motion in coupled-mode galloping. These results are consistent with previous theoretical research, offering a new approach to studying iced bundled conductors’ galloping.

To address the challenge of discontinuous operating bandwidth in energy harvesters subjected to ultra-low-frequency human motion and low-frequency vibration environments, this study proposes a wearable frequency up-conversion piezoelectric–electromagnetic hybrid energy harvester (FUCPEEH). In both ultra-low and low-frequency ranges, bidirectional coupling between the piezoelectric and electromagnetic modules enables efficient harvesting of human motion energy as well as low-frequency ambient vibration energy. A theoretical model is established and validated experimentally, demonstrating good agreement between simulation and measurement. Experimental results show that the harvester operates effectively over a broad 1.6–10 Hz frequency range. At a running speed of 9 km h ⁻¹ , the FUCPEEH delivers an output power of 95.8 mW and a power density of 177.4 μ W cm ⁻³ . By processing the piezoelectric signals generated by the FUCPEEH under ultra-low-frequency excitation using deep learning, accurate motion-state recognition and user identity recognition are achieved, with accuracies of 99.79% and 99.53%, respectively. A series of electrical demonstrations, including driving an LED array and charging commercial wireless earbuds, further verifies its capability to power wearable devices. These results indicate that the proposed FUCPEEH has substantial potential for applications in smart-city infrastructure and green intelligent living, such as health monitoring, and human–machine interaction.