Dual side control for inductive power transfer

Patent metadata

Field	Value
Publication number	US-9761370-B2
Application number	US-201313748187-A
Country	US
Kind code	B2
Filing date	Jan 23, 2013
Priority date	Jan 23, 2012
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

An apparatus for dual side control includes a measurement module that measures a voltage and a current of an IPT system. The voltage includes an output voltage and/or an input voltage and the current includes an output current and/or an input current. The output voltage and the output current are measured at an output of the IPT system and the input voltage and the input current measured at an input of the IPT system. The apparatus includes a max efficiency module that determines a maximum efficiency for the IPT system. The max efficiency module uses parameters of the IPT system to iterate to a maximum efficiency. The apparatus includes an adjustment module that adjusts one or more parameters in the IPT system consistent with the maximum efficiency calculated by the max efficiency module.

First claim

What is claimed is:

1. An apparatus comprising:
a measurement module that measures a voltage and a current of an inductive power transfer (“IPT”) system, the voltage comprising one or more of an output voltage and an input voltage, the current comprising one or more of an output current and an input current, the output voltage and the output current measured at an output of the IPT system, the input voltage and the input current measured at an input of the IPT system;
a max efficiency module that determines, using the voltage and current measured by the measurement module, a maximum efficiency for the IPT system, the max efficiency module using one or more models of elements of the IPT system and varying parameters of the IPT system within the one or more models of the IPT system to iterate to a maximum efficiency; and an adjustment module that adjusts one or more parameters in the IPT system consistent with the maximum efficiency calculated by the max efficiency module,
wherein the IPT system includes a first stage and a second stage, wherein the first stage transmits energy wirelessly and the second stage receives the wirelessly transferred energy and controls energy transfer to one or more loads via an output bus,
wherein the output voltage and the output current are measured on the output bus, wherein the one or more parameters varied by the max efficiency module and adjusted by the adjustment module comprise one or more of a duty cycle reference that adjusts a duty cycle of a switching power converter of the second stage and a conduction angle reference that adjusts conduction angle of a switching power converter of the first stage, wherein one parameter is used as the primary control variable and another parameter is updated to regulate output power.

2. The apparatus of claim 1 , wherein the first stage comprises an LCL load resonant converter and the second stage comprises one or more of a secondary resonant circuit, a secondary rectification circuit and a secondary decoupling circuit.

3. The apparatus of claim 2 , wherein at least one load comprises an energy storage device.

4. The apparatus of claim 1 , wherein the adjustment module adjusting one or more of the duty cycle reference and the conduction angle reference comprise an outer control loop, wherein one or more of
the first stage comprises a first stage inner loop controlling conduction angle based on the conduction angle reference, the first stage inner loop controlling conduction angle faster than the outer loop control; and
the second stage comprises a second stage inner loop controlling duty cycle based on the duty cycle reference, the second stage inner loop controlling duty cycle faster than the outer loop control.

5. The apparatus of claim 1 , wherein the max efficiency module determines the maximum efficiency by iterating using one or more variables, the one or more variables comprising:
conduction angle of the first stage;
duty cycle of the second stage;
size of a gap, the IPT system transferring power wirelessly across the gap;
misalignment of a primary receiver pad and a secondary receiver pad, the IPT system transferring power wirelessly from the primary receiver pad to the secondary receiver pad;
power transferred to the one or more loads; and
a quality factor.

6. The apparatus of claim 1 , wherein the max efficiency module determines the maximum efficiency by determining an efficiency of at least the first stage and the second stage for the measured voltage and current.

7. The apparatus of claim 6 , wherein the max efficiency module determines the maximum efficiency where efficiency of the IPT system is calculated as:
η=η r1 ·η c1 ·η r2 ·η b2 ·η c2 ,

wherein
η is IPT system efficiency;
η r1 is efficiency of the first stage without voltage drop;
η c1 is efficiency of first stage without linear resistance loss,
η r2 is efficiency of a secondary resonant circuit of the second stage;
η b2 is efficiency of a secondary rectification circuit and a secondary decoupling circuit of the second stage without voltage drop; and
η c2 is efficiency of the secondary rectification circuit and the secondary decoupling circuit of the second stage with linear resistance loss.

8. The apparatus of claim 7 , wherein the first stage comprises an LCL load resonant converter and the secondary decoupling circuit comprises a secondary boost converter and wherein η r1 is calculated as:

η

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R

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1

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R
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(

(

R

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Assignees

• Univ Utah State
• Us Energy

Inventors

• Wu Hunter
• Sealy Kylee
• Gilchrist Aaron

Classifications

• B60L53/126

  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 title

• H02J2105/37

  exchanging power with electric vehicles [EV] or with hybrid electric vehicles [HEV] · CPC title

• H02J7/933

  the cycle being controlled or terminated in response to electric parameters · CPC title

• Y02T10/7072

  Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors · CPC title

• H02J50/10

  using inductive coupling · CPC title