Investigation of High Altitude/Tropospheric Correction Factors for Electric Aircraft Applications

Arc Tracking Control in Insulation Systems for Aeronautic Applications: Challenges, Opportunities, and Research Needs

“…PDs and corona usually generate sound, light (mainly UV but also visible), wide frequency range radio interference voltage, electromagnetic wave energy, heat and chemical reactions. Under low pressure environments sound propagates with difficulty, so electromagnetic and UV-visible radiation can be used to detect corona [1,5]. Arcing in short gaps usually is preceded by corona discharges occurring at the region with highest electric field strength [11,78,79].…”

“…Arcing in short gaps usually is preceded by corona discharges occurring at the region with highest electric field strength [11,78,79]. Corona discharges are key sources of premature failure of insulation systems operating at high altitude [5], occurring earlier at low pressure than at atmospheric conditions [13,80], so surface discharges are among the main causes for early failure of electronic equipment operating in low pressure environments [13]. This is because air density is directly related to the development of electrical discharge development; any reduction of air density leads to a drop of the threshold value of the air ionization electric field, by which the arc is initiated [81].…”

“…This is because air density is directly related to the development of electrical discharge development; any reduction of air density leads to a drop of the threshold value of the air ionization electric field, by which the arc is initiated [81]. In [5] it is clearly demonstrated by means of long-exposure photographs that corona inception voltage (CIV) decreases with decreasing values of the atmospheric pressure. Early failure could be initiated because of the fast oxidation due to the ozone generated by the corona discharge [82], although early corona stages may not show any visible effects.…”

“…It is known that corona inception voltage has an important polarity dependency, since the CIV is lower for negative compared to positive polarity corona, but breakdown for positive polarity occurs at lower voltage than for negative polarity [71,78]. CIV is also influenced by the nature of voltage applied, i.e., DC, AC, switched DC or pulsed among others [5].…”

“…MEAs and AEAs will use more electrical power than their predecessors, since they replace pneumatic and hydraulic systems by electrical ones [3] to reduce the weight. Therefore, they are required to operate at higher voltage levels [4], above 1 kV [5], higher dV/dt, higher power densities and decreased wire distances. These modifications lead to new types of failure modes, including a higher risk of electric arc appearance, which can be potentially harmful [6].…”