IEC 63245-1:2021

Spatial wireless power transfer based on multiple magnetic resonances - Part 1: Requirements

IEC 63245-1:2021 specifies requirements for spatial wireless power transfer based on multiple magnetic resonances (SWPT-MMR), which is a non-radiative wireless power transfer (WPT). This document contains two categories of requirements: general requirements and functional requirements. The general requirements cover charging procedures and charging zones. The functional requirements cover each component of a SWPT-MMR system, such as transmitter coils.

Transfert d'énergie sans fil dans l'espace reposant sur des résonances magnétiques multiples - Partie 1: Exigences

L'IEC 63245-1:2021 spécifie les exigences relatives au transfert d’énergie sans fil dans l’espace reposant sur des résonances magnétiques multiples (SWPT-MMR), qui est un mode de transfert d’énergie sans fil (WPT) non radiatif. Le présent document contient deux catégories d’exigences: les exigences générales et les exigences fonctionnelles. Les exigences générales couvrent les procédures de charge et la zone de charge. Les exigences fonctionnelles couvrent chaque composant d’un système SWPT-MMR (les bobines de transmission, par exemple).

General Information

• Status: Published
• Publication Date: 08-Mar-2021
• ICS: 29.240.99 - Other equipment related to power transmission and distribution networks
• ICS: 35.200 - Interface and interconnection equipment
• Technical Committee: TA 15 - Wireless Power Transfer
• Drafting Committee: WG 1 - TC 100/TA 15/WG 1
• Current Stage: PPUB - Publication issued
• Start Date: 19-Mar-2021
• Completion Date: 09-Mar-2021

Standards Content (Sample)

IEC 63245-1
®

Edition 1.0 2021-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside


Spatial wireless power transfer based on multiple magnetic resonances –
Part 1: Requirements

Transfert d’énergie sans fil dans l’espace reposant sur des résonances
magnétiques multiples –
Partie 1: Exigences

IEC 63245-1:2021-03(en-fr)

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IEC 63245-1

®


Edition 1.0 2021-03




INTERNATIONAL



STANDARD




NORME


INTERNATIONALE
colour

inside










Spatial wireless power transfer based on multiple magnetic resonances –

Part 1: Requirements



Transfert d’énergie sans fil dans l’espace reposant sur des résonances

magnétiques multiples –

Partie 1: Exigences















INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE


INTERNATIONALE




ICS 29.240.99; 35.200 ISBN 978-2-8322-9470-3




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® Registered trademark of the International Electrotechnical Commission
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CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms, definitions, and abbreviated terms . 6
3.1 Terms and definitions . 6
3.2 Abbreviated terms . 7
4 Overview of spatial wireless power transfer . 7
5 General requirements . 9
5.1 Requirements on charging zone . 9
5.1.1 Three-dimensional charging zone . 9
5.1.2 Quiet zone . 9
5.1.3 Null point . 10
5.2 Requirements on charging procedure . 11
6 Functional requirements . 12
6.1 Requirements on transmitter coils . 12
6.1.1 Multiple transmitter coils . 12
6.1.2 Location of transmitter coils . 13
6.1.3 Relationship between two transmitter coils . 13
6.1.4 Structure of connecting a pair of transmitter coils . 13
6.2 Requirements on operations related to current . 14
6.2.1 Supplying current. 14
6.2.2 Controlling phase of current . 14
6.3 Requirements on frequency . 15
6.3.1 Adjusting resonance frequency . 15
Bibliography . 16

Figure 1 – Conceptual image of SWPT [IEC 62827-3] . 8
Figure 2 – Conceptual image of SWPT-MMR . 8
Figure 3 – Free positioning of a receiver in a charging zone . 9
Figure 4 – Interaction between transmitter coils for generating a quiet zone . 9
Figure 5 – Interaction between transmitter coils for generating a quiet zone (top view) . 10
Figure 6 – Null points in a charging zone (top view) . 10
Figure 7 – Addressing null points by using two pairs of transmitter coils (top view) . 11
Figure 8 – Basic charging procedure of SWPT-MMR . 12
Figure 9 – Arrangement of transmitter coils . 13
Figure 10 – Example of transmitter coils and a power supplier in an SWPT-MMR
system . 14

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IEC 63245-1:2021 © IEC 2021 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

SPATIAL WIRELESS POWER TRANSFER
BASED ON MULTIPLE MAGNETIC RESONANCES –

Part 1: Requirements

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 63245-1 has been prepared by technical area 15: Wireless power
transfer, of IEC technical committee 100: Audio, video and multimedia systems and equipment.
The text of this International Standard is based on the following documents:
FDIS Report on voting
100/3548/FDIS 100/3564/RVD

Full information on the voting for the approval of this International Standard can be found in the
report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 63245 series, published under the general title Spatial wireless
power transfer based on multiple magnetic resonances, can be found on the IEC website.

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IEC 63245-1:2021 © IEC 2021 – 5 –
INTRODUCTION
The IEC 63245 (Spatial wireless power transfer based on multiple magnetic resonances,
SWPT-MMR) series provides requirements and a reference model for implementing a spatial
wireless power transfer system. The IEC 63245 series consists of the following parts:
– IEC 63245-1: Spatial wireless power transfer based on multiple magnetic resonances –
Part 1: Requirements, which describes requirements of SWPTs with multiple magnetic
resonances; and
– IEC 63245-2: Spatial wireless power transfer based on multiple magnetic resonances –
Part 2: Reference model, which describes a reference model for SWPTs with multiple
magnetic resonances.

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SPATIAL WIRELESS POWER TRANSFER
BASED ON MULTIPLE MAGNETIC RESONANCES –

Part 1: Requirements



1 Scope
This part of IEC 63245 specifies requirements for spatial wireless power transfer based on
multiple magnetic resonances (SWPT-MMR), which is a non-radiative wireless power transfer
(WPT). This document contains two categories of requirements: general requirements and
functional requirements. The general requirements cover charging procedures and charging
zones. The functional requirements cover each component of a SWPT-MMR system, such as
transmitter coils.
2 Normative references
There are no normative references in this document.
3 Terms, definitions, and abbreviated terms
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1 Terms and definitions
3.1.1
null point
point or area in the charging zone where the magnetic field cancels out almost entirely or is
below a certain specified minimum
3.1.2
quiet zone
magnetic field having an equalized energy density corresponding to each of the magnetic fields
formed on the transmitter coils
3.1.3
spatial wireless power transfer
concept of wireless power transfer between multiple sources and multiple receiving devices
placed at a certain distance in various positions and postures within a space
Note 1 to entry: "Spatial" means that receiving devices will take various positions and postures, and will lead to
variable transfer efficiency including almost zero percent. This situation can occur when receiving devices are placed
far apart from the power source and are freely rearranged.
[SOURCE: IEC 62827-3:2016, 3.1.2, modified – In the definition, "receiving devices placed at
a certain distance in various positions and postures within a space" replaces "receiving devices
which are placed at a distance within a spatial space".]

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IEC 63245-1:2021 © IEC 2021 – 7 –
3.1.4
spatial wireless power transfer system
group implementing spatial wireless power transfer in which the power source can deliver power
and data to the power-receiving device
Note 1 to entry: In special cases, a spatial wireless power transfer system can consist of only a single power source
and only a single power-receiving device.
Note 2 to entry: Spatial wireless power transfer system includes the case in which a power source has the ability
to access a power-receiving device through a relay from other power sources when the power source attempts to
deliver data to the receiving device. In this document, "data" means control and management data for wireless power
transfer.
[SOURCE: IEC 62827-3:2016, 3.1.3]
3.1.5
transmitter coil
component of a wireless power transmitter that converts electric current to magnetic flux
[SOURCE: IEC 63006:2019, 3.1.48]
3.2 Abbreviated terms
2D two-dimensional
3D three-dimensional
SWPT spatial wireless power transfer
SWPT-MMR spatial wireless power transfer based on multiple magnetic resonances
WPT wireless power transfer
4 Overview of spatial wireless power transfer
IEC TR 62869 describes types of WPT physical layer technologies. Among the technologies,
electromagnetic induction and magnetic resonance technologies are dominantly used in recent
industries. The IEC PAS 63095 and WPC Qi series specifies WPT based on electromagnetic
induction technology, whereas IEC 63028 specifies WPT based on magnetic resonance
technology.
A spatial wireless power transfer (SWPT) system delivers the electronic power to one or more
receivers within a spatial space. Figure 1 shows a conceptual image of SWPT described in
IEC 62827-3.

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Figure 1 – Conceptual image of SWPT [IEC 62827-3]
Spatial wireless power transfer based on multiple magnetic resonances (SWPT-MMR) is a
specific implementation of SWPT. Similar to IEC 63028, SWPT-MMR is based on magnetic
resonance. However, SWPT-MMR includes multiple magnetic resonances to generate a
charging zone. In the charging zone, electric power is transferred to one or more receivers
regardless of the position and direction of the receiver(s). Figure 2 shows a conceptual image
of SWPT-MMR. As shown in Figure 2, an SWPT-MMR system generates a charging zone in a
specific space with multiple magnetic resonances.

Figure 2 – Conceptual image of SWPT-MMR

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IEC 63245-1:2021 © IEC 2021 – 9 –
5 General requirements
5.1 Requirements on charging zone
5.1.1 Three-dimensional charging zone
An SWPT-MMR system generates a three-dimensional charging zone for SWPT. In the charging
zone, the power-receiving device has an increased degree of freedom in a 3D space to expand
a range of wireless power transmission in a process of performing wireless charging when
compared to a pad structure corresponding to a two-dimensional (2D) area. Figure 3 depicts
various positionings of a receiver in a charging zone.

Figure 3 – Free positioning of a receiver in a charging zone
REQ-ZONE1: an SWPT-MMR system shall be capable of generating a 3D charging zone.
5.1.2 Quiet zone
For transferring electric energy to a receiver in any position within a 3D charging zone, energy
density in the charging zone shall be equalized corresponding to each of the magnetic fields
formed on the transmitting coils. To equalize energy density within the charging zone, at least
one pair of transmitter coils are arranged to face each other and they generate a magnetic field
by using the current supplied from at least one power source. The 3D space with equalized
energy density is referred to as a "quiet zone". Figure 4 and Figure 5 show interaction between
transmitter coils for generating a quiet zone. A pair of transmitter coils generates a quiet zone
in one direction. To add a quiet zone in another direction, an additional pair of transmitter coils
can be arranged.

Figure 4 – Interaction between transmitter coils for generating a quiet zone

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Inward and outward currents of the same colour belong to the same transmitter coil.
Figure 5 – Interaction between transmitter coils for generating a quiet zone (top view)
REQ-ZONE2: an SWPT-MMR system shall be capable of generating a quiet zone indicating a
magnetic field having an equalized energy density in the charging zone.
REQ-ZONE3: an SWPT-MMR system shall be capable of controlling multiple transmitter coils
to generate multiple quiet zones.
5.1.3 Null point
In a charging zone, a null point is a point or area where the magnetic field cancels out almost
entirely or is below a certain specified minimum. Figure 6 depicts null points in a charging zone.

Inward and outward currents of the same colour belong to the same transmitter coil.
Figure 6 – Null points in a charging zone (top view)

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IEC 63245-1:2021 © IEC 2021 – 11 –
To deal with null points, an SWPT-MMR system can have two pairs of transmitter coils. Figure 7
shows an example of an SWPT-MMR system equipped with two pairs of transmitter coils; each
transmitter coil can be identified by its colour. As shown in Figure 7, red and blue transmitter
coils generate a quiet zone on the y-axis, and green and yellow transmitter coils generate a
quiet zone on the x-axis. A quiet zone on one axis can eliminate the null point of a quiet zone
on another axis.

Inward and outward currents of the same colour belong to the same transmitter coil.
Figure 7 – Addressing null points by using two pairs of transmitter coils (top view)
REQ-ZONE4: an SWPT-MMR system shall be capable of dealing with null points in a charging
zone.
REQ-ZONE5: it is recommended that an SWPT-MMR system be capable of generating multiple
quiet zones in different directions.
5.2 Requirements on charging procedure
Figure 8 shows a basic charging procedure of SWPT-MMR. In standby state, an SWPT-MMR
prepares for generating a charging zone. After initialization, an SWPT-MMR system generates
a charging zone in the SWPT-MMR system. During this step, a quiet zone will be formed in the
generated charging zone. As a next step, the SWPT-MMR system can optimize the charging
zone based on the location and angle of a receiver coil in a power receiver. The optimization
may include adjusting the phase of current or the resonant frequency, and the SWPT-MMR
system and a receiver can communicate through various methods, such as Bluetooth Low
1
Energy or Zigbee™ , for the optimization. In addition, the SWPT-MMR system in standby state
may use the various communication methods for detecting a receiver. The SWPT-MMR system
can start power transmission when optimization is complete, and it can terminate power
transmission based on the charging status of the power receiver.
_____________
1
 Zigbee is the trademark of a product supplied by the ZigBee Alliance Corporation. This information is given for
the convenience of users of this document and does not constitute an endorsement by IEC of the product named.
Equivalent products may be used if they can be shown to lead to the same results.

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REQ-PROC1: it is recommended that an SWPT-MMR system follow the basic charging
procedure comprised of standby state, charging zone generation, optimization, power
transmission, and transmission termination.
REQ-PROC2: it is recommended that an SWPT-MMR system include a communication module
to interact with a receiver for optimization procedure.
REQ-PROC3: it is recommended that an SWPT-MMR system include a communication module
to detect a receiver in standby state.

Figure 8 – Basic charging procedure of SWPT-MMR
6 Functional requirements
6.1 Requirements on transmitter coils
6.1.1 Multiple transmitter coils
As described in 5.1, an SWPT-MMR system needs to have multiple transmitter coils.
REQ-COIL1: an SWPT-MMR system shall have at least a pair of transmitter coils for generating
a quiet zone on one axis.
REQ-COIL2: an SWPT-MMR system shall have at least two pairs of transmitter coils for
handling null points occurring on each axis of a quiet zone.

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IEC 63245-1:2021 © IEC 2021 – 13 –
6.1.2 Location of transmitter coils
Transmitter coils of an SWPT-MMR system can be placed at various locations in the system.
For example, a box-shaped SWPT-MMR system can have one transmitter coil on each wall.
Then, the coils can be placed on the centre of each wall. When the box-shaped SWPT-MMR
system has two transmitter coils on each wall, the upper part of a wall can have a transmitter
coil and the bottom part of the wall can have another transmitter coil.
REQ-COIL3: an SWPT-MMR system shall be capable of accommodating transmitter coils
placed at various locations in the system.
6.1.3 Relationship between two transmitter coils
In order to form a quiet zone, two transmitter coils of an SWPT-MMR system are recommended
to face each other as a pair. To generate quiet zones on multiple axes, an SWPT-MMR system
can have multiple pairs of transmitter coils. Figure 9 shows an example of the SWPT-MMR
system with two pairs of transmitter coils.

Figure 9 – Arrangement of transmitter coils
REQ-COIL4: an SWPT-MMR system shall have a pair of transmitter coils arranged to face each
other in the charging zone.
6.1.4 Structure of connecting a pair of transmitter coils
An SWPT-MMR system has at least one pair of transmitter coils facing each other and at least
one power supplier for supplying current to the coils. Figure 10 shows the configuration of an
SWPT-MMR system consisting of a power supplier and two transmitter coils, which are
connected in parallel or in series.

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Figure 10 – Example of transmitter coils and
a power supplier in an SWPT-MMR system
REQ-COIL5: an SWPT-MMR system shall have at least one pair of transmitter coils, which are
connected in parallel or in series.
REQ-COIL6: an SWPT-MMR system shall have at least one power supply.
6.2 Requirements on operations related to current
6.2.1 Supplying current
An SWPT-MMR system has at least two transmitter coils. The transmitter coils are connected
with a power supplier as shown in Figure 10, and the power supplier shall supply current to the
transmitter coils.
REQ-CUR1: an SWPT-MMR system shall be capable of supplying currents to at least two pairs
of transmitting coils.
6.2.2 Controlling phase of current
To generate a charging zone, an SWPT-MMR system may have multiple pairs of transmitter
coils. In such a case, an in-phase or an out-of-phase current will be provided to each pair of
transmitters in order to generate a charging zone.
REQ-CUR2: an SWPT-MMR system shall supply an in-phase current or an out-of-phase current
to each pair of transmitter coils when the SWPT-MMR system has multiple pairs of transmitter
coils.
REQ-CUR3: an SWPT-MMR system shall be capable of controlling the phase of the current
supplied to the plurality of transmitting coils included in the wireless charging zone.
REQ-CUR4: an SWPT-MMR system shall be capable of controlling a phase of
...