Experimental investigation on correlation of corona‐induced vibration and audible noise from DC conductor

Ground total electric field (GTEF) is a vital parameter in the field of electromagnetic environment of high voltage direct current (HVDC) lines. Some experimental works reported that airborne suspended particles can be charged in the corona ion flow of the lines and thus affect GTEF. This paper aims at studying the charging models for particles. Equivalent unipolar charging models (EUCMs) and bipolar charging models (BCMs) for describing field and diffusion charging mechanisms in bipolar ion environments are introduced and the Maxwell-Wagner relaxation is proposed to be incorporated. Besides, the EUCMs and BCMs are analysed and validated through comparisons with experimental data. The results show that BCMs are applicable to describing the particle charging in a bipolar ion environment, while EUCMs are not. The predictions made by BCM that takes into account the Maxwell-Wagner relaxation are in good agreement with experimental results. Moreover, the BCMs are proposed to analyse the experimental results about GTEF in the presence of particles, which are not understood before. It is demonstrated that the BCMs are able to qualitatively explain these results. Finally yet importantly, a new charging model combining field and diffusion charging mechanism is proposed for airborne suspended particles around HVDC lines and validated by experiments. The results show that the proposed hybrid field-diffusion charging model is able to give predictions consistent with experiments. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

“…In Equations (1) and (6), ϕ(r) is the electrostatic potential of the ions in the field of the particle at the distance r…”

Section: Diffusion Charging -The Fuchs' Modelmentioning

confidence: 99%

Charging models for airborne suspended particles around HVDC lines

et al. 2021

“…where E[] is the mathematical expectation and ∇ θ denotes the partial differential respect to variable θ. From the narrowband radio propagation path-loss model in (1), the CRLB for unbiased distance estimators can be expressed as [29] var d^≥ ln 10 ⋅ σ ⋅ d 10η (12) where d^ represents an unbiased estimate for the distance d.…”

Section: Crlb Analysis With Measurement Noisementioning

confidence: 99%

“…Besides, a line of CRLB, which is added in Fig. 10, which is computed via (12). Node that CRLB is the lower bound of all the unbiased estimations which are based on (2).…”

Section: Performances With Crlb Line At a Certain Positionmentioning

confidence: 99%

“…With the large-scale implementations of HVDC transmission lines, the environmental impacts due to electromagnetic waves have become a focus of public attention in the following technical parameters: electric field [6][7][8], ion current density, space charge density [9], radio interference [10,11], audible noise [12,13], corona discharge [14][15][16][17] etc. In contrast to the HVAC transmission lines, the electric field under HVDC lines is greatly enhanced when a corona discharge occurs and an accurate and efficient measurement method is needed to assure the system follows the electromagnetic environmental standard.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Received signal strength indication‐based localisation method with unknown path‐loss exponent for HVDC electric field measurement

Cui

Wang

et al. 2017

The electric field environment under high-voltage direct current (HVDC) transmission lines is an important design consideration. In the wireless sensor networks for electric field measurement system under the HVDC transmission lines, it is necessary to obtain the electric field distribution with multiple sensors. The accurate localisation of sensing nodes is essential to the analysis of measurement results. However, most current techniques are limited to constant measurement environment with fixed and known path-loss exponent. Here, the authors report a localisation method based on received signal strength indication with unknown path-loss exponent for the localisation of one-dimensional linear topology wireless networks in the electric field measurement system. The optimisation method is utilised to obtain the optimal pass-loss parameter without involving the previous environment parameters. Afterwards, simulations are employed to demonstrate the feasibility and the effectiveness of the proposed method by comparing with other methods.

“…It has been proved that through measurement of time‐domain waveform of sound pressure, real‐time sound pressure signals which reflect the vibration of gas molecules can be obtained. The random nature of corona‐generated AN and correlation between the AN and the corona discharge can be clearly reflected through the detail characteristics of the time‐domain waveform of AN [17, 21]. Furthermore, the real‐time background noise can also be recorded through time‐domain measurement.…”

Section: Introductionmentioning

confidence: 99%

Statistical analysis of audible noise generated by AC corona discharge from single corona sources

Wang

et al. 2018

Self Cite

Time-domain waveforms of sound pressure pulses generated by alternate current (AC) corona discharge from single corona sources are measured. The pulse amplitude and time interval of sound pressure pulses in positive and negative half cycles are analysed separately due to large differences of the sound pressure pulses in positive and negative half cycles. The influences of instantaneous voltages on the pulse amplitude and time interval are obtained, and statistical distributions of pulse amplitude and time interval are also obtained. Besides, empirical formulas of the pulse amplitude and time interval are derived by numerical fitting method. Based on the statistical results, stochastic simulation of the sound pressure pulses is conducted, and the validity of the simulated results is given by comparing the frequency-domain results and A-weighted sound pressure level (SPL) with the measured ones. Finally, the stochastic simulation method is used to discuss modulating influence of AC voltage on the tones emission from AC corona discharge. Besides, the influence of the measurement time on the resultant SPL is also discussed on the basis of the stochastic model. In order to insure the SPL independent of the measurement time, the measurement time should be larger than 0.2 s.