A reasonable acoustic power formula is vital to precisely evaluate the audible noise (AN) level of ultra-high-voltage (UHV) AC power lines. This study derived a formula by taking several AN measurements under heavy rain conditions, using multiple conductor bundles in a UHV corona cage, and then subjecting these measured values to least squares fitting. The validity of the proposed formula was subsequently verified with statistical data obtained from two long-term stations at Henan and Hubei Province, which are located under the Jindongnan-Nanyang-Jingmen UHV AC transmission lines operating at 1000 kV. The deviation between the prediction and the long-term (L50) value was 0.76 dB for the Henan station and 0.17 dB for the Hubei station. It shows that the acoustic power formula derived in this paper is more accurate than the widely used Bonneville Power Administration formula, in which the corresponding deviations are much larger (3.07 and 2.53 dB).

Radio interference (RI) induced by the corona discharge of alternating current transmission lines is more severe at high altitudes than at low altitudes; hence, RI is a crucial limiting factor in the structural design of transmission lines and environmental impact assessments. To determine RI performance at high altitudes, the State Grid Corporation of China constructed an ultrahigh-voltage (UHV) corona cage in Xining in 2015 at an altitude of 2261 m. In this study, the cage was used to investigate a high number of bundled conductors under heavy rain. An RI excitation function was derived from Xining and the effects of several variables on RI performance were analyzed. In addition, RI altitude corrections were studied by comparing the Xining data with data obtained from a UHV corona cage in Wuhan located at an altitude of 23 m. The RI correction value was verified not to be a constant value but rather one that changed with the surface electric field and bundle size. The correction values obtained in this paper could enable the RI levels of high-voltage alternating current transmission lines at high altitudes to be evaluated more precisely.

The audible noise (AN) induced by corona discharge of AC transmission lines is more severe at high altitudes than at low altitudes; this has become a crucial limiting factor for the structural design of power lines and their environmental impact assessment. To determine the altitude effect and correction of AN level for AC power lines, a corona cage test system was used to measure the acoustic power level of four bundled conductors at five elevations, namely Wuhan (23 m), Tianshui (1100 m), Xining (2261 m), Gonghe (2943 m), and Yangbajain (4300 m). We obtained the AN characteristics for different altitudes, bundle numbers, and subconductor diameters through a statistical analysis of measured data. The analysis and comparison results indicate that the actual AN correction values are slightly less than the Bonneville Power Administration term of 1 dB/300 m at altitudes below 3200 m. Above 3200 m, the difference increases gradually. A correction term 2.85 dB/1000 m is recommended for more accurate evaluation.

Thanks to the development of deep learning, various sound source separation networks have been proposed and made significant progress. However, the study on the underlying separation mechanisms is still in its infancy. In this study, deep networks are explained from the perspective of auditory perception mechanisms. For separating two arbitrary sound sources from monaural recordings, three different networks with different parameters are trained and achieve excellent performances. The networks’ output can obtain an average scale-invariant signal-to-distortion ratio improvement (SI-SDRi) higher than 10 dB, comparable with the human performance to separate natural sources. More importantly, the most intuitive principle—proximity—is explored through simultaneous and sequential organization experiments. Results show that regardless of network structures and parameters, the proximity principle is learned spontaneously by all networks. If components are proximate in frequency or time, they are not easily separated by networks. Moreover, the frequency resolution at low frequencies is better than at high frequencies. These behavior characteristics of all three networks are highly consistent with those of the human auditory system, which implies that the learned proximity principle is not accidental, but the optimal strategy selected by networks and humans when facing the same task. The emergence of the auditory-like separation mechanisms provides the possibility to develop a universal system that can be adapted to all sources and scenes.

With the development of ultrahigh voltage (UHV) transmission lines in China, line corridors are becoming increasingly limited, and the lines pass closer to inhabited areas and the occurrence probability of induced electric shocks are increased. The research on transient electric shock and human sensory is essential due to the displeasure and complaints of people on electric shock. In this article, a real-size metal shed was established near a 1000-kV UHV alternating current (ac) transmission line, and the induced voltage and transient current characteristics were studied when the human body was in contact with the shed. Then, the amplitude and pulsewidth of the transient electric shock current were investigated, and the associations between discharge energy and sensation were established. The research found that transient electric shock is the most serious when the grounded human body contacts the insulated shed, and the imparted electric shock energy reaches 25 mJ. When the body and the shed are grounded, there is no electric shock sensation. When the insulated human body is in contact with the insulated shed, the electric shock sensation is intermediate, and women's perceptions of pain are more intense. The results provide references to transient electric shock protection for power transmission lines.

At high altitudes, the corona discharge of alternating current transmission lines is more severe, and the induced radio interference (RI) level is higher. Foul weather, especially rain, can aggravate RI performance. In this article, to investigate the influence of rain intensity on RI level at high altitudes, an ultra-high-voltage (UHV) corona cage was employed to perform RI measurements for four bundled conductors (4 × LGJ 630, 6 × LGJ 500, 8 × LGJ 500 and 8 × LGJ 630) by using an artificial rain system at an altitude of 2261 m. The RI levels of the four conductors were obtained under fair weather and under 1.5, 2, 6, 12, and 18 mm/h of rainfall. Then, the RI performances of a 1000 kV UHV single circuit lines and a 1000 kV double circuit line on the same tower were calculated using the excitation function approach. Finally, the difference between predicted RI values at high altitude and long-term measurements for operational power lines at low altitude were discussed.