Figures (15)  Tables (5)

    • Figure 1. 

      ECPT system architecture based on double-sided LC compensation topology.

    • Figure 2. 

      Schematic diagram of the UAV and its electric field coupling structure.

    • Figure 3. 

      Equivalent circuit of coupling mechanism. (a) Coupling mechanism model. (b) Current source model. (c) Equivalent π model.

    • Figure 4. 

      Coupling mechanism variation curve. (a) Mutual capacitance (b) Coupling coefficient.

    • Figure 5. 

      Power loss density distribution of different typical dielectric materials. (a) Tempered glass. (b) Silicon carbide. (c) Alumina ceramics.

    • Figure 6. 

      Bilateral LC type resonant topology under π equivalent model.

    • Figure 7. 

      Equivalent circuit of bilateral LC resonant network under π model.

    • Figure 8. 

      Equivalent circuit of bilateral LC resonant network under T model.

    • Figure 9. 

      Equivalent circuit of bilateral LC resonant network after inductor splitting.

    • Figure 10. 

      Equivalent circuit of bilateral LC compensation ECPT system.

    • Figure 11. 

      Experimental prototype of the wireless charging system.

    • Figure 12. 

      Block diagram of the experimental system architecture.

    • Figure 13. 

      System waveforms at R = 50 Ω (output power: 200 W, DC-DC efficiency: 87%).

    • Figure 14. 

      System waveforms at R = 10 Ω (output power: 200 W, DC-DC efficiency: 84.2%).

    • Figure 15. 

      Variation of DC-DC efficiency under different load resistances.

    • Typical dielectric
      materials      		 Relative complex
      dielectric constant      		 CM (pF) Cin1−CM (pF) Cin2−CM (pF)
      Tempered glass 5.5-j1.2e-10 65.52 11.43 0.111
      Silicon carbide 10-j1.2e7 116.22 12 0.110
      Muscovite 5.7-j2.41e-11 67.77 11.45 0.111
      Alumina ceramics 9.8-j1.2e-10 113.97 11.98 0.110
      Hard rubber 3-j1.2e-11 37.27 11.08 0.114
      Polyvinyl chloride 3.4-j6e-10 41.8 11.14 0.113
      Mylar 3.1-j1.2e-9 38.41 11.1 0.113
      Nylon 4-j1.2e-8 48.59 11.23 0.112

      Table 1. 

      Relative complex permittivity of typical dielectric materials and mutual capacitance of coupling mechanisms.

    • Typical dielectric
      materials      		 C12 (pF) C13 (pF) C14 (pF) C23 (pF) C24 (pF) C34 (pF)
      Tempered glass 11.32 131 0.10535 0.11187 131.27 0.0025
      Silicon carbide 11.9 232.3 0.10403 0.11045 232.79 0.00243
      Muscovite 11.35 135.52 0.10525 0.11176 135.79 0.00249
      Alumina ceramics 11.87 227.8 0.10406 0.11048 228.28 0.00243
      Hard rubber 10.97 74.59 0.10772 0.11439 74.72 0.00262
      Polyvinyl chloride 11.03 83.64 0.10711 0.11375 83.79 0.00259
      Mylar 10.99 76.86 0.10755 0.11421 76.99 0.00261
      Nylon 11.12 97.19 0.10643 0.11301 97.37 0.00255

      Table 2. 

      Coupling capacitance of typical dielectric materials.

    • Parameter Expression Parameter Expression
      YL1 $ \dfrac{1}{j\omega {L}_{1}} $ YL2 $ \dfrac{1}{j\omega {L}_{2}} $
      YC1 $ j\omega {C}_{1} $ YC2 $ j\omega {C}_{2} $
      Y1 $ j\omega {C}_{1}+\dfrac{1}{j\omega {L}_{1}} $ Y2 $ j\omega {C}_{2}+\dfrac{1}{j\omega {L}_{2}} $
      YM $ j\omega {C}_{{\mathrm{M}}} $ YRL $ \dfrac{1}{{R}_{{\mathrm{L}}}} $

      Table 3. 

      Admittances of the circuit components.

    • Parameter Value Parameter Value
      f (MHz) 1.5 Vdc (V) 50
      L1 (μH) 30.7 Cex1 (pF) 330
      L2 (μH) 30.7 Cex2 (pF) 330
      CM (pF) 33.1 Cin1 (pF) 39.1
      Kc 0.0898 Cin2 (pF) 39.1
      RL (Ω) 10–50

      Table 4. 

      System parameters.

    • Vdc (V) P (w) Efficiency (%) Weight (g) Power density (W/g) Ref.
      100 107 81.4 (DC-DC) 56 1.9 [14]
      150 325 86 (DC-DC) 368 0.88 [15]
      40 87 87.1 (DC-DC) 56.4 1.5 [16]
      52 312 89 (DC-DC) 300 1.04 [17]
      50 200 87 (DC-DC) 90 2.22 This study

      Table 5. 

      Comparison of UAV ECPT systems.