Christopher L. Halsall

Bio: Christopher L. Halsall is an academic researcher from University of the West of Scotland. The author has contributed to research in topics: Conducted electromagnetic interference & Electromagnetic interference. The author has an hindex of 1, co-authored 1 publications receiving 3 citations.

Harmonics and Electromagnetic Interference

Abstract: Electrical interference is an unwanted consequence of power electronics apparatus. This issue is addressed by highlighting the main controlling factors and by developing equations that assist in quantifying the severity of the problem. Both themes are directed at power frequency harmonics: they are also applied to electromagnetic interference where, in addition, the techniques for interference suppression are considered, as are the methods by which this phenomenon is measured.

On How Harmonic Interference Does Influence the Forming of Pulse-Width Modulation Signal

Abstract: This paper is devoted to finding a relationship between harmonic interference on a data transfer and the pulse duration errors in transmitting an informative signal. Looking for a noise immunity in the case of pulse-width modulation makes sense if we can’t rely upon fiber-optic channels and other stationary equipment only. Surging interferences on a channel transmitting a pulse modulated signal result in a jitter on the leading and falling edges of the pulses. If the noise influence can’t be eliminated, a data transfer errors occur, inherent to the pulse-width modulation and other kinds of pulse modulation. At the time of making the paper, the authors were exploring a rationale for how the time lapse fixing errors are dependent on harmonic interference parameters. Here we give a grounding for the rule of the distribution law for the triggering moment of a rectangular pulse shaper. It is shown, that any straightforward measures are not enough to reduce these errors. The rule of probability density distribution of the time when the forming device gets triggered, is stated not only as a whole, many widespread cases are shown as well. The resulting analytics can be used both to find a trade-off between parameters of a device operating in a noisy condition, and as a measure of the pure theoretical limit pulse-width modulation as well.

Electrical energy quality role on the globe

Abstract: The end-consumers need high quality of electrical energy like safe, continuous voltage supply with the required current at constant rms values and at constant frequency, then pure sinusoid waveform of voltage. If the rated voltage of computers will be dropping down to its 75% the disturbance in their operation appears and at 50% they will loose their ability for work, then the acquired data, the envisaged commands will be lost. Flicker occurs when high power is fluctuating providing changes in voltage that makes the human eyes fatigue. Long-term flicker severity index must be less than unity otherwise it jeopardizes the smooth operation of other consumers In the vicinity of huge arc furnaces in urban area networks a basic flicker index ranging between 0.2 and 0.25 was recorded. Harmonic spectrum is different if computers working only in a room, then the total harmonic distortion was 3.47%. When luminescent light sources were also working the distortion increased up to 4.71% and when welding equipment were added in a workshop the total harmonic distortion went up to 10.98%. If it reaches 10% then the acquired data, commands, control signals will be lost, the operation of consumers and manufacturing process will be out of order, thus re-installation or even repair is needed for the computers.

Electrical Energy Quality Role on the Globe

Abstract: The end-consumers need high quality of electrical energy like safe, continuous voltage supply with the required current at constant rms values and at constant frequency, then pure sinusoid waveform of voltage. If the rated voltage of computers will be dropping down to its 75% the disturbance in their operation appears and at 50% they will loose their ability for work, then the acquired data, the envisaged commands will be lost. Flicker occurs when high power is fluctuating providing changes in voltage that makes the human eyes fatigue. Long-term flicker severity index must be less than unity otherwise it jeopardizes the smooth operation of other consumers In the vicinity of huge arc furnaces in urban area networks a basic flicker index ranging between 0.2 and 0.25 was recorded. Harmonic spectrum is different if computers working only in a room, then the total harmonic distortion was 3.47%. When luminescent light sources were also working the distortion increased up to 4.71% and when welding equipment were added in a workshop the total harmonic distortion went up to 10.98%. If it reaches 10% then the acquired data, commands, control signals will be lost, the operation of consumers and manufacturing process will be out of order, thus re-installation or even repair is needed for the computers.