Overview of the arc mechanism and extinguishing in the circuit breaker of a more-electric aircraft
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摘要: 多電飛機指次級功率從機械能、液壓能、氣壓能等傳統的多能源體制統一為電能體制的飛機，具有系統結構簡單、可靠性高、可維護性高和能源利用率高等優點，其電力系統最先進的架構為360～800 Hz變頻交流電源和270 V直流電源，目前已在空客A380、波音B787、F-22等多電飛機中應用。但隨著用電功率的增加，多電飛機的配電、用電網絡以及線纜布局將變得更復雜，發生短路等電氣故障的概率明顯加大。故障電流產生的電弧不僅嚴重影響線纜和用電設備的壽命、可靠性和安全性，還將限制航空電力系統擴容和飛行性能提升。多電飛機斷路器是滅弧的關鍵器件，通過分析斷路器中電弧放電過程的復雜機理，可有助于提升其滅弧性能。為深入推進多電飛機電力系統中斷路器電弧理論與滅弧技術研究的開展，首先分析了民用和軍用多電飛機電力系統的結構以及電氣故障保護的難點，然后分別歸納了航空變頻交流斷路器和270 V直流斷路器中電弧理論與滅弧技術的研究現狀，最后預測了未來航空保護電器滅弧技術的發展趨勢。
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關鍵詞:
- 多電飛機 /
- 航空270 V直流電力系統 /
- 變頻電力系統 /
- 航空斷路器 /
- 電弧
Abstract: A more-electric aircraft refers to an aircraft whose secondary power is unified from the traditional multi-energy, such as mechanical energy, hydraulic energy, and pneumatic energy, to the electrical energy, which has the advantages of a simple system structure, high reliability, high maintainability, and high energy efficiency. The most advanced architecture of its power system is the 360–800 Hz variable frequency AC power supply and the 270 V high-voltage DC power supply, which have been applied in the Airbus A380, Boeing B787, F-22, and other more-electric aircraft. As power consumption increases, the power distribution, power network, and cable layout in a more-electric aircraft become more complex, and the probability of electrical faults such as short circuits increases. The arc generated by fault current not only severely affects the life, reliability, and safety of cable and electrical equipment but also limits the capacity expansion of an aviation power system and the improvement of flight performance. The circuit breaker in a more-electric aircraft is a key device for arc extinguishing. Analyzing the complex mechanism of the arc-discharging process in a circuit breaker helps improve the arc-extinguishing performance. To further promote research on the arc mechanism and extinguishing technology of circuit breakers in more-electric aircraft power systems, in this paper, the structure of civilian and military more-electric aircraft power systems and the difficulties in the electrical fault and protection are first analyzed. Then, the research status of the arc-extinguishing technology of the aviation variable frequency AC circuit breaker and the 270 V high-voltage DC circuit breaker are summarized. For an intermediate-frequency vacuum arc, the instantaneous input power inside the gap and at the anode increases with the current frequency, which indicates that the half-wave input power increases with the frequency and proves that the transition state arc is an important source of anode ablation during intermediate-frequency arcing. Under the same current condition, the frequency increases. On the one hand, when the value of di/dt increases, the arc-extinguishing ability decreases with increasing frequency. On the other hand, intensifying the skin effect leads to an increase in the arc center pressure, arc contraction, and magnetic field hysteresis, which is not conducive to arc extinguishing. In addition, the metal vapor density vaporized by droplets reduces the recovery strength of the dielectric after the current zero, which is not conducive to arc extinguishing. For the 270 V DC arc, air, nitrogen, helium, hydrogen, and other gas are presently used in aviation power systems, among which hydrogen is the research hotspot. Finally, future research trends of arc extinguishing technology for aviation circuit breakers are predicted. -
圖 3 電弧的危害. (a) 電弧帶來火災隱患; (b) 電弧燒蝕斷路器觸頭表面
Figure 3. Arc hazard: (a) fire hazards by arc; (b) ablated contact surface of circuit breaker by arc
圖 4 中頻真空電弧的磁場仿真計算. (a) 中頻真空電弧區域的磁場分布; (b) 開距中間平面的磁場分布
Figure 4. Magnetic field simulation of an intermediate-frequency vacuum arc: (a) magnetic field distribution in the intermediate-frequency vacuum arc region; (b) magnetic field distribution in the middle plane
圖 5 中頻弧后擊穿過程中的金屬液滴噴射現象
Figure 5. Metal droplet jetting during post-arc breakdown at intermediate frequency
圖 6 一種自然換流混合式斷路器. (a) 斷路器結構; (b) 滅弧過程的仿真
Figure 6. Hybrid circuit breaker with natural commutation: (a) structure of the circuit breaker; (b) simulation of the arc-extinguishing process
表 1 典型民用多電飛機的變頻電力系統
Table 1. Variable frequency power supply system of a typical civil more-electric aircraft
Type Power of ME/(kV·A) Phase voltage /
VFrequency of ME /Hz Power of APU/(kV·A) Frequency of
APU/HzPower of RAT
/(kV·A)A320ME 4×75 115 360–800 2×120 400 2×80 A380/C919 4×150 115 360–800 2×120 400 70 B787 4×250 230 360–800 2×225 400 10 
下載: 導出CSV
中文字幕在线观看表 2 典型軍用多電飛機的直流電力系統
Table 2. 270 V DC power supply system of a typical military more-electric aircraft
Type Power of ME/kW Power of APU/kW Voltage level/V Short-circuit current/kA F-22 2 × 65 22 270 2.5 F-35 2 × 125 200 270 5
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