Application of Pressure Scanners in Wind Load Effect Testing of Power Transmission Structures

I. Types of Power Transmission Structures and Background of Wind-Induced Issues in Cable-Supported Transmission Systems

When discussing power transmission, people often think of common roadside facilities such as overhead conductors and transmission towers. From a structural perspective, however, power transmission systems can be broadly classified into three categories: conventional tower–line transmission structures, cable transmission systems, and cable-supported (guyed or suspended) transmission structures. Among these, the traditional tower–line structure is the most widely used, while cable transmission systems are mainly deployed underground or subsea.

In complex terrains such as mountainous regions, deep valleys, and Karst Landforms, the applicability of the first two structural types is significantly limited due to difficulties in tower siting and high construction costs. Under such constraints, cable-supported transmission structures have emerged as an effective alternative.

Cable-supported transmission structures use steel frames and suspended cables to span across mountainous terrain, offering advantages such as simple structural configuration, lower investment, and ease of installation. They are particularly well suited for power transmission projects in western China and other mountainous areas. However, these structures are essentially long-span, highly flexible cable systems, and their wind resistance performance becomes a critical issue in design and safety assessment. This concern is further exacerbated in high-altitude, low-temperature, and high-humidity environments, where icing phenomena are common.

Icing not only alters the geometric shape and mass distribution of the suspended cables, but also leads to more complex aerodynamic responses under wind action. When the approaching flow exhibits strong turbulence characteristics, iced cables may experience amplified vibrations, galloping, or even aerodynamic instability under wind loads, posing a serious threat to the safe operation of transmission lines. Therefore, investigating the wind load characteristics and wind-induced stability of iced cables in cable-supported transmission structures under turbulent flow conditions is of clear practical significance.

II. Experimental Research Approach and Pressure Measurement Methods

To address the complex wind field conditions encountered by cable-supported transmission structures in real service environments, wind tunnel testing is widely adopted as the primary research approach. By generating incoming flows with different turbulence characteristics in the wind tunnel, researchers can systematically investigate the effects of turbulence on mean aerodynamic forces, fluctuating wind pressure distributions, and unsteady aerodynamic behavior of iced cables.

In typical experiments, representative cross-sectional models of iced suspended cables are selected, and force and pressure measurements are conducted under varying wind attack angles and turbulence intensities. Turbulent flow fields are generally simulated using grid devices. Based on this setup, the model is installed in the test section, and a large number of pressure taps are arranged along the circumferential and spanwise directions on the model surface.

By synchronously acquiring pressure signals from these taps, the instantaneous wind pressure characteristics resulting from the coupling between turbulent inflow and structural vibration can be captured. This enables analysis of the mean pressure distribution of iced cables in turbulent flow, the spatial distribution of fluctuating wind pressure as a function of turbulence parameters, and the sensitive regions of aerodynamic force variation under different icing configurations.

III. Importance of Pressure Scanners

In wind tunnel tests of iced suspended cables in cable-supported transmission structures, accurate acquisition of fluid pressure data is a fundamental basis for evaluation and analysis. As high-precision, multi-channel pressure acquisition devices, pressure scanners are indispensable equipment in such experiments.

First, these tests involve a large number of measurement points, with a single acquisition often requiring dozens or even hundreds of channels. This demand aligns well with the multi-channel capabilities of pressure scanners. For example, pressure scanners from KETU&TEST are available in various channel configurations and can be interconnected via network switches to achieve up to 1,024 channels of synchronous data acquisition, enabling large-scale pressure measurement tasks.

Second, pressure signals in turbulent wind fields exhibit pronounced transient characteristics, which place stringent requirements on the dynamic response and sampling synchronization of the measurement system. KETU&TEST pressure scanners offer an accuracy better than ±0.05% FS and a sampling rate of up to 10 kHz. Through long-term application in wind tunnel and fluid mechanics experiments, as well as close collaboration with multiple universities and research institutes, these systems have demonstrated the ability to reliably capture high-frequency fluctuating wind pressure signals. This provides a solid data foundation for subsequent aerodynamic spectrum analysis and unsteady model development.

In addition, experiments related to cable-supported transmission structures often involve numerous repeated test conditions and long-duration operation, imposing high requirements on equipment stability and reliability. KETU&TEST pressure scanners undergo tens of thousands of verification tests prior to delivery and are designed for long-term stable operation, making them well suited for such demanding experimental scenarios.

As a key technology for power transmission in complex terrains, cable-supported transmission structures require thorough investigation of their wind resistance and anti-icing stability. Through wind tunnel testing combined with high-precision pressure scanners, researchers are able to gain deep insight into the complex aerodynamic characteristics of iced structures under turbulent environments. In this type of experimental research, pressure scanners from KETU&TEST provide robust technical support and contribute to enhancing the safety and stability of power infrastructure.