power_transfer_architecture_of_the_qi_standard
Differences
This shows you the differences between two versions of the page.
| Both sides previous revisionPrevious revisionNext revision | Previous revision | ||
| power_transfer_architecture_of_the_qi_standard [2025/05/01 10:27] – tm | power_transfer_architecture_of_the_qi_standard [2025/05/01 14:11] (current) – [4.Negotiation phase] tm | ||
|---|---|---|---|
| Line 1: | Line 1: | ||
| =====Power Transfer Architecture of the Qi Standard===== | =====Power Transfer Architecture of the Qi Standard===== | ||
| - | ====Establishing power transfer==== | ||
| The transmitter (Tx) and receiver (Rx) go through an advanced process for power to be transferred. This process comprises **four phases** in the **baseline power profile (BPP)**, namely the selection, ping, identification & configuration, | The transmitter (Tx) and receiver (Rx) go through an advanced process for power to be transferred. This process comprises **four phases** in the **baseline power profile (BPP)**, namely the selection, ping, identification & configuration, | ||
| Line 7: | Line 6: | ||
| ====1. Selection phase==== | ====1. Selection phase==== | ||
| - | In the selection phase, the transmitter (Tx) monitors the characteristics of its resonant circuit to detect the presence of a potential receiver (Rx). This can also be an unwanted foreign object. When a Qi-compatible device is brought near, its coil interacts with the Tx coil through mutual inductance. This coupling alters the Tx's resonance frequency and impedance. By observing these changes, the Tx infers the presence of an object. No data communication occurs at this stage, and the Rx remains inactive. (The Qi Wireless Power Transfer System Class 0 Specification 1 and 2: Interface Definitions, | + | In the selection phase, the transmitter (Tx) monitors the characteristics of its resonant circuit to detect the presence of a potential receiver (Rx). This can also be an unwanted foreign object. When a Qi-compatible device is brought near, its coil interacts with the Tx coil through mutual inductance. This coupling alters the Tx's resonance frequency and impedance. By observing these changes, the Tx infers the presence of an object. No data communication occurs at this stage, and the Rx remains inactive (The Qi Wireless Power Transfer System Class 0 Specification 1 and 2: Interface Definitions, |
| ====2. Ping phase==== | ====2. Ping phase==== | ||
| Line 24: | Line 23: | ||
| This phase can only be accessed through EPP or MPP capable devices with **[[Foreign object detection in the Qi standard|foreign object detection (FOD)]]**. In this phase the Tx and Rx review their power transfer contract. The purpose of the negotiation phase is to fine-tune this contract. The Rx sends a negotiation request to the Tx to which it replies with a message of granting, denying or not recognising the request. Both the sender and the receiver keep a copy of the current contract. This temporary copy is used to store updated parameters until the negotiation phase is successfully completed. | This phase can only be accessed through EPP or MPP capable devices with **[[Foreign object detection in the Qi standard|foreign object detection (FOD)]]**. In this phase the Tx and Rx review their power transfer contract. The purpose of the negotiation phase is to fine-tune this contract. The Rx sends a negotiation request to the Tx to which it replies with a message of granting, denying or not recognising the request. Both the sender and the receiver keep a copy of the current contract. This temporary copy is used to store updated parameters until the negotiation phase is successfully completed. | ||
| + | |||
| As part of this phase, the Rx also sends the reference **[[Foreign object detection in the Qi standard|quality factor (Q-factor)]]** value to the Tx. This value reflects the Q-factor measured under ideal conditions without any foreign objects. The Tx uses this value to determine a threshold for FOD by comparing it with the Q-factor measured on its own primary coil. If the measured Q-factor falls below this threshold, the Tx may terminate the power transfer. These Q-factor evaluations and threshold settings are performed during the negotiation phase to ensure safe and efficient operation. | As part of this phase, the Rx also sends the reference **[[Foreign object detection in the Qi standard|quality factor (Q-factor)]]** value to the Tx. This value reflects the Q-factor measured under ideal conditions without any foreign objects. The Tx uses this value to determine a threshold for FOD by comparing it with the Q-factor measured on its own primary coil. If the measured Q-factor falls below this threshold, the Tx may terminate the power transfer. These Q-factor evaluations and threshold settings are performed during the negotiation phase to ensure safe and efficient operation. | ||
| + | |||
| With the MPP this process is simplified. The magnetic attachment within the new MPP mode tightly secures transmitter and receiver coils in optimal positions. Therefore, the coupling factor always hovers around a value of 1. This makes the negotiation and FOD procedures faster and more predictable than in EPP (The Qi Wireless Power Transfer System Class 0 Specification 1 and 2: Interface Definitions, | With the MPP this process is simplified. The magnetic attachment within the new MPP mode tightly secures transmitter and receiver coils in optimal positions. Therefore, the coupling factor always hovers around a value of 1. This makes the negotiation and FOD procedures faster and more predictable than in EPP (The Qi Wireless Power Transfer System Class 0 Specification 1 and 2: Interface Definitions, | ||
| Line 46: | Line 47: | ||
| * **Safety stop**: The exit can also be triggered by various, previously discussed, safety features: overheating protection, FOD or aborted communication between Tx and Rx. | * **Safety stop**: The exit can also be triggered by various, previously discussed, safety features: overheating protection, FOD or aborted communication between Tx and Rx. | ||
| - | The BPP control architecture of the Qi standard is shown in Figure 1. Figure 2 presents the EPP control architecture. This architecture also applies to MPP, as the structure remains the same (Evolution of Qi Wireless Charging Standard & What’s New With Qi2, n.d.; The Qi Wireless Power Transfer System Class 0 Specification 1 and 2: Interface Definitions, | + | The BPP control architecture of the Qi standard is shown in Figure 1. Figure 2 presents the EPP control architecture. This architecture also applies to MPP, as the structure remains the same (GRL, n.d.; Holtek, 2022, p. 4; Technologies, |
| - | | {{: | + | | {{: |
| | Figure 1 BPP architecture of communication (Holtek, 2022, p. 4) | | | Figure 1 BPP architecture of communication (Holtek, 2022, p. 4) | | ||
| - | | {{: | + | | {{: |
| | Figure 2 EPP architecture of communication (Technologies, | | Figure 2 EPP architecture of communication (Technologies, | ||
| Line 58: | Line 59: | ||
| <color # | <color # | ||
| * <color # | * <color # | ||
| - | * <color # | + | * <color #808080>GRL. (n.d.). |
| - | * <color # | + | * <color #808080>MPS. (2018). |
| * <color # | * <color # | ||
| * <color # | * <color # | ||
power_transfer_architecture_of_the_qi_standard.1746095250.txt.gz · Last modified: by tm