Uniform magnetic field transmitter

• US 9,975,441 B2
• Filed: 12/16/2015
• Issued: 05/22/2018
• Est. Priority Date: 12/17/2014
• Status: Active Grant

• Current Assignee: New York University
• Original Assignee: New York University
• Inventors: Huang, Jingduo, Czarkowski, Dariusz, Leon, Francisco De, Bojarski, Mariusz
• Primary Examiner(s): Diao, M'Baye
• Application Number:
  US14/971,060
• Publication Number:
  US 20160176301A1
• Time in Patent Office: 888 Days
• Field of Search: 320108
• CPC Class Codes: B60L 53/12 Inductive energy transfer
• CPC Class Codes: B60L 53/126 Methods for pairing a vehicle and a charging station, e.g. establishing a one-to-one relation between a wireless power transmitter and a wireless power receiver
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

A system for wirelessly charging an electric vehicle comprises a wireless charging coil having a first end, a second end, and a plurality of turns. The first end has a first turn having a first radius r₁ and the second end has an N^th turn having an N^th radius r_N, r_N<r₁ such that the wireless charging coil is funnel shaped,

• • where, an ascending distance between each adjacent turn of the wireless charging coil is:
    Δ′_j,j+1=Δ_{j+i−3,j+i−2}+(Δ′₃₄−Δ_i,i+1), for j≥4 and r′_j+1>0
  • where,
  • Δ′_j,j+1=r′_j−r′_j+1 is the distance between adjacent turns,
  • σ is between 0.05% and 0.2%,
  • i is 2 to N;
  • j is 1 to N; and
  • Δ′₃₄ is an ascending distance between the third turn and the fourth turn.

Claims

1. A non-transitory computer readable medium for determining horizontal and vertical turn distributions of a wireless charging coil, when executed by a computing device, cause the computing device to perform operations, comprising:

setting a number of turns (N) of the wireless charging coil equal to 0 and a parameter g equal to 0;

calculating an initial turn distribution of the wireless charging coil;

adjusting a horizontal turn distribution of the wireless charging coil;

setting a vertical turn distribution of the wireless charging coil;

removing redundant turns of the wireless charging coil;

setting a depth (d) of the wireless charging coil equal to 0;

determining if a uniformity factor of the wireless charging coil satisfies a predetermined requirement;

determining if the depth d<

a maximum depth (d_max)/N, in response to the uniformity factor not satisfying the predetermined requirement;

incrementing a value of d in response to d<

a maximum depth (d_max)/N;

determining if g<

20, in response to d not less than d_max/N;

incrementing a value of g, in response to g<

20;

incrementing a value of N, in response to g not less than 20;

determining horizontal and vertical turn distribution of the wireless charging coil, in response to the uniformity factor satisfying the predetermined requirement; and

displaying the horizontal and vertical turn distribution of the wireless charging coil to a user.

2. The computer readable medium of claim 1, wherein the wireless charging coil is funnel shaped.

3. The computer readable medium of claim 1, wherein the turns include a plurality of circular turns aligned along a longitudinal axis of the wireless charging coil.

4. The computer readable medium of claim 1, wherein the predetermined requirement of the uniformity factor includes the uniformity factor being less than 12%.

5. The computer readable medium of claim 1, wherein the value of N is incremented from 0 to infinity with a step of 1.

6. The computer readable medium of claim 1, wherein the value of g is incremented from 1 to 20 with a step of 0.05.

7. The computer readable medium of claim 1, wherein the value of d is incremented from 0 to d_max/N with a step of change in d (δ

d).

8. The computer readable medium of claim 1, wherein the removing of the redundant turns of the wireless charging coil is performed until the uniformity factor satisfies at least one of a near ideal uniformity condition, or 20% of the turns in the wireless charging coil are removed.

9. A system for wirelessly charging an electric vehicle, comprising;

a wireless charging coil having a first end, a second end, and a plurality of turns, the first end having a first turn and the second end having an N^th turn, the first turn having a first radius r₁ and the N^th turn having an N^th radius r_N, r_N<

r₁ such that the wireless charging coil is funnel shaped,

wherein, an ascending distance between each adjacent turn of the wireless charging coil is;

Δ

′

_j,j+1=Δ

<sub>j+i−

3,j+i−

2</sub>+(Δ

′

₃₄−

Δ

_i,i+1),for j≥

4andr′

_j+1>

0

wherein,

Δ

′

_j,j+1=r′

_j−

r′

_j+1 is the distance between adjacent turns,

i is 2 to N;

j is 1 to N;

Δ

′

₃₄ is an ascending distance between the third turn and the fourth turn

Δ

<sub>j+i−

3,j+i−

2</sub> is the distance between adjacent turns; and

Δ

_i,i+1 is the distance between adjacent turns.

10. The system of claim 9, wherein the distance between the first turn r₁ and a second turn r′

₂ is between 0.25% and 0.9% of r₁ such that a variance of a field strength H_z(x)(var(Hz)) is minimized, wherein,

11. The system of claim 10, wherein a uniformity factor (λ

_uniform) of the wireless charging coil is less than 12%.

12. The system of claim 9, wherein the plurality of turns include a plurality of circular turns aligned along a longitudinal axis of the wireless charging coil.