Auxiliary Circuits for Selection and Enhancement of Multi-Frequency Wireless Power Transfer to Multiple Loads

• US 20150228402A1
• Filed: 02/12/2014
• Published: 08/13/2015
• Est. Priority Date: 02/12/2014
• Status: Active Grant

• Current Assignee: University of Hong Kong (Government of Hong Kong Special Administrative Region)
• Original Assignee: University of Hong Kong (Government of Hong Kong Special Administrative Region)
• Inventors: HUI, Shu Yuen Ron, ZHONG, Wenxing
• Granted Patent: US 9,787,102 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/50 using additional energy repeaters between transmitting devices and receiving devices

Abstract

This invention is related to a novel method and apparatus that provides selective and enhanced power flow in wireless power transfer systems with multiple receivers. Auxiliary circuits are introduced in the receiver circuits (and relay circuits if applicable) so as to ensure proper frequency-selective wireless power flow to the appropriate targeted receivers, with the pickup power by the non-targeted receivers substantially reduced even if the chosen tuned frequencies for different receivers are not widely apart.

Claims

1. A wireless power transfer system for transferring power at more than one frequency, comprising:

a transmitter capable of transmitting power wirelessly at more than one frequency;

a first targeted receiver for receiving power at a first frequency from the transmitter;

a second non-targeted receiver for receiving power at a second frequency, but not the first frequency from the transmitter;

an auxiliary circuit in said second non-targeted receiver, so as to ensure proper frequency-selective wireless power flow from said second non-targeted receiver to the targeted receiver, with pickup power retained by the non-targeted receiver substantially reduced, even if the chosen tuned frequencies for targeted and non-targeted receivers are not widely separated.

2. The power transfer system of claim 1 wherein the auxiliary circuit acts as one of a bandpass filter to shunt power at the first frequency to ground before a load of the second receiver and a bandstop filter to prevent the flow of the power at the first frequency to the load of the second receiver.

3. The power transfer system of claim 1 wherein the auxiliary circuit causes a part of the second receiver to act as a resonator for the first frequency so as to transmit power from the first receiver to the second receiver at the first frequency.

4. The power transfer system of claim 1 wherein the second receiver is a relay circuit.

5. The power transfer system of claim 2 wherein a receiver comprises a resonant inductor, a resonant capacitor and a load, the load may be connected in series with the resonant inductor and capacitor or in parallel with the resonant capacitor;

and wherein the auxiliary circuit is further designed to act as a resonator for the first frequency so as to transmit power from the first receiver to the second receiver at the first frequency.

6. The power transfer system of claim 5, wherein the resonant capacitor is in two parts connected in series with one part of the resonant capacitor connected to one side of the load, and

wherein the auxiliary circuit is a band-pass filter that includes the resonant capacitor, an auxiliary inductor and an auxiliary capacitor connected, the auxiliary capacitor and inductor are connected in series between the two parts of the resonant capacitor and the other side of the load.

7. The power transfer system of claim 5, wherein the resonant capacitor is in two parts with one part connected in parallel with the load and the other part connected in series with the load and the resonant inductor, and

wherein the auxiliary circuit is a band-pass filter that includes the resonant capacitor, an auxiliary inductor and an auxiliary capacitor wherein the auxiliary inductor and auxiliary capacitor are connected in series and the combination is connected in parallel with the one part of the resonant capacitor and the load.

8. The power transfer system of claim 5, wherein the resonant capacitor is in two parts with one part connected in series with one side of the load, and

wherein the auxiliary circuit is a band-stop filter that includes an auxiliary inductor and an auxiliary capacitor connected in parallel with each other and connected in series with the resonant inductor at a junction and the one part of the resonant capacitor, said auxiliary circuit further including the other part of the resonant capacitor, which is connected between junction of the auxiliary capacitor and inductor with the resonant inductor and the other side of the load.

9. The power transfer system of claim 5, wherein the resonant capacitor is in two parts with one part connected in parallel with the load, and

the auxiliary circuit is a band stop filther that includes an auxiliary inductor and an auxiliary capacitor connected in parallel with each other and connected in series with the resonant inductor at a junction and with the load, the said auxiliary circuit further including the one part of the resonant capacitor and the other part of the resonant capacitor, which is connected between junction of the auxiliary capacitor and inductor with the resonant inductor and the other side of the load.