CN112550009B - Wireless charging foreign matter detection device and electric vehicle parking auxiliary device - Google Patents

Wireless charging foreign matter detection device and electric vehicle parking auxiliary device Download PDF

Info

Publication number
CN112550009B
CN112550009B CN202011364909.7A CN202011364909A CN112550009B CN 112550009 B CN112550009 B CN 112550009B CN 202011364909 A CN202011364909 A CN 202011364909A CN 112550009 B CN112550009 B CN 112550009B
Authority
CN
China
Prior art keywords
difference
value
array
coil
acquiring
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202011364909.7A
Other languages
Chinese (zh)
Other versions
CN112550009A (en
Inventor
蹇林旎
章程
牛松岩
喻航
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Southwest University of Science and Technology
Original Assignee
Southwest University of Science and Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Southwest University of Science and Technology filed Critical Southwest University of Science and Technology
Priority to CN202011364909.7A priority Critical patent/CN112550009B/en
Publication of CN112550009A publication Critical patent/CN112550009A/en
Application granted granted Critical
Publication of CN112550009B publication Critical patent/CN112550009B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L53/00—Methods of charging batteries, specially adapted for electric vehicles; Charging stations or on-board charging equipment therefor; Exchange of energy storage elements in electric vehicles
    • B60L53/10—Methods of charging batteries, specially adapted for electric vehicles; Charging stations or on-board charging equipment therefor; Exchange of energy storage elements in electric vehicles characterised by the energy transfer between the charging station and the vehicle
    • B60L53/12—Inductive energy transfer
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L53/00—Methods of charging batteries, specially adapted for electric vehicles; Charging stations or on-board charging equipment therefor; Exchange of energy storage elements in electric vehicles
    • B60L53/10—Methods of charging batteries, specially adapted for electric vehicles; Charging stations or on-board charging equipment therefor; Exchange of energy storage elements in electric vehicles characterised by the energy transfer between the charging station and the vehicle
    • B60L53/12—Inductive energy transfer
    • B60L53/124—Detection or removal of foreign bodies
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L53/00—Methods of charging batteries, specially adapted for electric vehicles; Charging stations or on-board charging equipment therefor; Exchange of energy storage elements in electric vehicles
    • B60L53/10—Methods of charging batteries, specially adapted for electric vehicles; Charging stations or on-board charging equipment therefor; Exchange of energy storage elements in electric vehicles characterised by the energy transfer between the charging station and the vehicle
    • B60L53/12—Inductive energy transfer
    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L53/00—Methods of charging batteries, specially adapted for electric vehicles; Charging stations or on-board charging equipment therefor; Exchange of energy storage elements in electric vehicles
    • B60L53/30—Constructional details of charging stations
    • B60L53/35—Means for automatic or assisted adjustment of the relative position of charging devices and vehicles
    • B60L53/36—Means for automatic or assisted adjustment of the relative position of charging devices and vehicles by positioning the vehicle
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L53/00—Methods of charging batteries, specially adapted for electric vehicles; Charging stations or on-board charging equipment therefor; Exchange of energy storage elements in electric vehicles
    • B60L53/30—Constructional details of charging stations
    • B60L53/35—Means for automatic or assisted adjustment of the relative position of charging devices and vehicles
    • B60L53/38—Means for automatic or assisted adjustment of the relative position of charging devices and vehicles specially adapted for charging by inductive energy transfer
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
    • G01V3/00—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation
    • G01V3/08—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices
    • G01V3/10—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices using induction coils
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J50/00—Circuit arrangements or systems for wireless supply or distribution of electric power
    • H02J50/10—Circuit arrangements or systems for wireless supply or distribution of electric power using inductive coupling
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J50/00—Circuit arrangements or systems for wireless supply or distribution of electric power
    • H02J50/60—Circuit arrangements or systems for wireless supply or distribution of electric power responsive to the presence of foreign objects, e.g. detection of living beings
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J50/00—Circuit arrangements or systems for wireless supply or distribution of electric power
    • H02J50/90—Circuit arrangements or systems for wireless supply or distribution of electric power involving detection or optimisation of position, e.g. alignment
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/70—Energy storage systems for electromobility, e.g. batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/7072—Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02T90/10—Technologies relating to charging of electric vehicles
    • Y02T90/12—Electric charging stations
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02T90/10—Technologies relating to charging of electric vehicles
    • Y02T90/14—Plug-in electric vehicles

Abstract

The device comprises a supporting plate, a first detection coil unit, a second detection coil unit, a signal acquisition and processing module and a metal foreign matter judgment circuit, wherein the first detection coil unit and the second detection coil unit are stacked on the first surface of the supporting plate and used for acquiring an induced electric signal of a closed detection coil caused by magnetic field change between an electric power transmitting device and a vehicle electric power receiving end in a charging process; the signal acquisition and processing module is used for acquiring the induced electrical signal of the first detection coil unit to generate a first sampled electrical signal and acquiring the induced electrical signal of the second detection coil unit to generate a second sampled electrical signal; the metal foreign matter judgment circuit is used for judging whether metal foreign matters exist according to the received first sampling electric signal and the second sampling electric signal, and intelligent detection of the metal foreign matters in a magnetic field coupling space of the wireless charging system is achieved.

Description

Wireless charging foreign matter detection device and electric vehicle parking auxiliary device
Technical Field
The application relates to the technical field of wireless charging of electric vehicles, in particular to a wireless charging foreign matter detection device and an electric vehicle parking auxiliary device.
Background
With the rapid development of industry and the continuous promotion of urbanization process, automobiles, especially household cars, are used as the most convenient and fast mode of transportation and travel, and the number of the automobiles is increased sharply. Statistics show that the automobile keeping quantity in China reaches 2.5 hundred million vehicles and the private vehicles reach 1.98 hundred million vehicles in the last half year of 2019. Automobiles have been introduced into thousands of households as a medium-to-high grade consumer product. However, in recent decades, the number of automobiles has increased dramatically, which results in excessive consumption of fossil fuels and global warming, and automobile exhaust gas has become one of important environmental pollution sources. In order to improve such a situation, energy-saving and environment-friendly Electric Vehicles (EVs) have been researched and developed to effectively alleviate the demand for fossil energy and gradually improve the environment. Wireless Power Transfer (WPT) is a non-contact Power transmission method. The basic principle is wireless power transmission using electromagnetic induction. Through long-time development, the wireless charging technology has the advantages of non-contact, no need of manual operation, portability, mobility and the like, and is popular among people. The technology is applied to electric energy transmission of automobiles, a series of problems of wire aging or electric leakage and the like in wired transmission are avoided, and the charging equipment is packaged and laid under the ground, so that the requirement of manual maintenance is reduced.
However, the wireless charging technology also has some disadvantages, for example, there is a space between the primary device and the secondary device of the wireless charging system, and during the alignment of the vehicle for charging, the magnetic field coupling coefficient between the primary and the secondary is easily reduced due to the deviation of the spatial position, which results in low charging efficiency of the device; because the spacing space exists between the primary side equipment and the secondary side equipment, when external foreign matters enter the magnetic field coupling area and the foreign matters are metal, an alternating electromagnetic field in the charging process can form an eddy current effect on the surface of the metal, so that the temperature of the metal foreign matters is rapidly increased, and inflammable matters such as surrounding weeds, paper scraps and the like are easily ignited by the high temperature of the metal foreign matters, so that the safety problems such as fire and the like are caused.
Disclosure of Invention
Accordingly, in view of the above-mentioned problems in the background art, it is desirable to provide a wireless charging foreign object detection apparatus and an electric vehicle parking assist apparatus capable of intelligently detecting whether a metal foreign object exists in a magnetic field coupling space of a wireless charging system, so as to avoid unnecessary damage and economic loss caused by an eddy current effect generated by the foreign metal foreign object in the magnetic field coupling space.
To achieve the above and other objects, a first aspect of the present application provides a wireless charging foreign matter detection device, including:
the supporting plate is placed above a plane where the ground-side power transmitting device is located, and a first surface of the supporting plate is parallel to the plane where the power transmitting device is located;
the first detection coil unit is arranged on the first surface of the supporting plate, comprises a plurality of first coils arranged along a first direction and is used for respectively acquiring induced electric signals of the closed detection coil caused by the change of a magnetic field between the power transmitting device and a vehicle power receiving end in the charging process, and the induced electric signals comprise induced voltage and/or induced current;
the second detection coil unit is arranged on the first surface, is stacked with the first detection coil unit, comprises a plurality of second coils arranged along a second direction and is used for acquiring the induced electrical signals, the orthographic projection of the second detection coil unit on the first surface is overlapped with the orthographic projection of the first detection coil unit on the first surface, and the center of the overlapped area and the center of the power transmitting device are positioned on a straight line perpendicular to the first surface;
the signal acquisition and processing module is respectively connected with the first detection coil unit and the second detection coil unit and is used for acquiring the induced electrical signal of the first detection coil unit to generate a first sampling electrical signal and acquiring the induced electrical signal of the second detection coil unit to generate a second sampling electrical signal;
and the metal foreign matter judgment circuit is connected with the signal acquisition and processing module and used for receiving the first sampling electrical signal and the second sampling electrical signal and judging whether metal foreign matters exist according to the first sampling electrical signal and the second sampling electrical signal.
In the wireless charging foreign object detection device in the above embodiment, the support plate is disposed above the plane where the ground-side power transmission device is located, and the first surface of the support plate is disposed parallel to the plane where the power transmission device is located; then, arranging a first detection coil unit comprising a plurality of first coils arranged along a first direction on the first surface of the supporting plate, and arranging a second detection coil unit which is arranged in a stacked manner with the first detection coil unit, wherein the orthographic projection of the second detection coil unit on the first surface is overlapped with the orthographic projection of the first detection coil unit on the first surface, and the center of an overlapped area and the center of the power transmitting device are positioned on a straight line perpendicular to the first surface; respectively acquiring induced electric signals of a closed detection coil caused by magnetic field change between the power transmitting device and a vehicle power receiving end in a charging process by utilizing each first coil in the first detection coil unit and each second coil in the second detection coil unit, wherein the induced electric signals comprise induced voltage and/or induced current; the signal acquisition and processing module is respectively connected with the first detection coil unit and the second detection coil unit and is used for acquiring the induced electrical signal of the first detection coil unit to generate a first sampling electrical signal and acquiring the induced electrical signal of the second detection coil unit to generate a second sampling electrical signal; the metal foreign matter judgment circuit connected with the signal acquisition and processing module judges whether metal foreign matter exists according to the received first sampling electric signal and the second sampling electric signal, intelligent detection of the metal foreign matter in a magnetic field coupling space of the wireless charging system is achieved, the phenomenon that foreign metal foreign matter enters a magnetic field coupling area and is influenced by an alternating electromagnetic field in the charging process to form eddy current on the metal surface, the temperature of the metal foreign matter rises rapidly, and the metal foreign matter causes the ignition of surrounding inflammable matters such as weeds, paper scraps and the like, and the safety problems of fire and the like are solved.
In one embodiment, the first coils are rectangular coils and are even in number, the second coils are rectangular coils and are even in number, the first coils are arranged in an equidistant linear array along the first direction, the second coils are arranged in an equidistant linear array along the second direction, and the first direction is perpendicular to the second direction;
two pairs of first coils at the central part of the first detection coil unit are paired in a staggered mode to form a first difference-finding coil pair respectively;
in the first coils except the first difference-finding coil pair in the first detection coil unit, the first coils at symmetrical positions form second difference-finding coil pairs respectively;
two pairs of second coils at the central part of the second detection coil unit are paired in a staggered mode to form a third difference-finding coil pair respectively;
in the second detection coil unit, in addition to the third difference-finding coil pair, second coils located at symmetrical positions form fourth difference-finding coil pairs respectively;
the metal foreign matter judgment circuit further comprises a first difference value operation circuit, a second difference value operation circuit and a processor;
the first difference operation circuit is connected with each first difference coil pair and each second difference coil pair and is used for calculating the difference of the induced electric signals of the two first coils in each first difference coil pair and the difference of the induced electric signals of the two first coils in the second difference coil pair to form a first difference array;
the second difference operation circuit is connected with each third difference coil pair and each fourth difference coil pair, and is used for calculating the difference of the induced electrical signals of the two second coils in each third difference coil pair and the difference of the induced electrical signals of the two second coils in the fourth difference coil pair to form a second difference array;
the processor is connected to both the first difference operation circuit and the second difference operation circuit, and is configured to:
acquiring the first difference value array, and acquiring a difference value reference value corresponding to each difference value in the first difference value array to form a first difference value reference value array;
acquiring the second difference value array, and acquiring a difference value reference value corresponding to each difference value in the second difference value array to form a second difference value reference value array;
and judging whether metal foreign matters exist according to the first difference value array, the first difference value reference value array, the second difference value array and the second difference value reference value array.
In one embodiment, the processor is configured to:
calculating the difference degree of any difference value in the first difference value array, and acquiring a difference value reference value corresponding to the difference value; if the difference degree is larger than or equal to the difference reference value, judging that metal foreign matters exist;
calculating the difference degree of any difference value in the second difference value array, acquiring a difference value reference value corresponding to the difference value, and judging that a metal foreign body exists if the difference degree is greater than or equal to the difference value reference value;
under the condition that the metal foreign body exists, acquiring a code of a first coil or a code of a second coil corresponding to the difference value so as to determine the position of the metal foreign body according to the codes;
for any difference value x and the difference reference value y corresponding to the difference value x, the difference degree γ of the difference value x is calculated according to the following formula:
Figure BDA0002805125730000051
in one embodiment, two pairs of first coils of the central portion of the first detection coil unit are symmetrically paired to form a first summing coil pair, respectively; two pairs of second coils at the central part of the second detection coil unit are symmetrically paired to form a second summation coil pair respectively;
the metal foreign matter judgment circuit further comprises a first sum operation circuit and a second sum operation circuit;
the first sum operation circuit is connected with the first summing coil pair and the processor and is used for calculating the sum of the induced electric signals of two first coils in the first summing coil pair to form a first sum array;
the second sum operation circuit is connected with the second summing coil pair and the processor and is used for calculating the sum of the induced electric signals of the two second coils in the second summing coil pair to form a second sum array;
the processor is configured to:
acquiring the first sum value array, and acquiring sum value reference values corresponding to the sum values in the first sum value array to form a first sum value reference value array;
acquiring the second sum value array, and acquiring sum value reference values corresponding to the sum values in the second sum value array to form a second sum value reference value array;
judging whether metal foreign matters exist or not according to the first sum value array, the first sum value reference value array, the second sum value array and the second sum value reference value array;
if any sum value in the first sum value group is smaller than or equal to the corresponding sum value reference value, judging that metal foreign matters exist in the central area of the power transmitting device; and
and if any sum value in the second sum value array is less than or equal to the corresponding sum value reference value, judging that metal foreign matters exist in the central area of the power transmitting device.
A second aspect of the present application provides an electric vehicle parking assist apparatus for assisting an electric vehicle to park for charging, comprising:
in any of the embodiments of the present application, the wireless charging foreign object detection apparatus, wherein the processor is configured to:
acquiring the induction voltage of any one first coil in the first direction under the condition that no metal foreign matter is found in idle load detection after charging request and the electric vehicle enters a parking space
Figure BDA0002805125730000061
Current I of the transmitting coil of the power transmitting apparatus1Current I of receiving coil of the power receiving device2A mutual inductance value M between the transmission coil of the power transmission device and the first detection coil unitGA-SensorAnd a preset angular frequency value omega, and the mutual inductance value M between the first detection coil unit and the receiving coil of the power receiving device is calculated according to the following formulaVA-Sensor：
Figure BDA0002805125730000071
According to the mutual inductance value MVA-SensorAnd performing comparison operation by using a preset offset-mutual inductance curve to judge the offset condition of the electric vehicle and assist the electric vehicle to stop and align.
In one embodiment, the processor is further configured to:
acquiring a mutual inductance value of a first coil in the first detection coil unit, and judging a variation trend of the mutual inductance value of the first coil in real time in the moving process of the electric vehicle, so as to judge whether the offset of the electric vehicle in the first direction is greater than or equal to a first preset offset threshold value or not according to the variation trend and the offset-mutual inductance curve, and if so, controlling to execute a preset warning action; and/or
And acquiring a mutual inductance value of a second coil in the second detection coil unit, judging the change trend of the mutual inductance value of the second coil in real time in the moving process of the electric vehicle, judging whether the offset of the electric vehicle in the second direction is greater than or equal to a second preset offset threshold value according to the change trend and the offset-mutual inductance curve, and if so, controlling to execute a preset warning action.
In one embodiment, the processor is further configured to:
acquiring a mutual inductance value M between the first detection coil unit and a reception coil of the power reception deviceVA-Sensor；
Obtaining the real-time current value I of the transmitting coil of the power transmitting device under the condition that the vehicle deviates1-realtimeA real-time current value I of a receiving coil of the power receiving device2-realtimeThe power transmitting device and the power receiving device sense the induced voltage U on the coilTargetInduced voltage U of the coil is detected symmetricallyTargetSubtracting to obtain the voltage deviation U introduced by the offsetRemove. According to the voltage self-zeroing scheme, the voltage difference semaphore detected on the coil pair is detected in real time, and the calculated voltage difference semaphore U generated due to offset is subtractedRemoveTo obtain a product only due to the presence of metallic foreign matterVoltage U generated on the detection coilMetal-Sensor；
By comparing the voltage U generated on the detection coil due to the presence of metallic foreign matterMetal-SensorAnd the difference value reference value to judge whether metal foreign matters exist or not and determine the positions of the metal foreign matters, and the induced voltage U of the power transmitting device and the power receiving device on the detection coilTargetCalculated according to the following formula:
Figure BDA0002805125730000081
in one embodiment, the warning action includes at least one of controlling to stop charging, sending a warning prompt message or sending a vehicle body deviation prompt message.
In one embodiment, the processor is further configured to:
after controlling to execute a preset offset self-zero procedure, controlling to start charging the charging vehicle;
acquiring a first voltage difference value array, and acquiring voltage difference value thresholds corresponding to the voltage difference values in the first voltage difference value array to form a first voltage difference value threshold array, wherein the first voltage difference value array is composed of difference values of induction voltages of two first coils in the first difference coil pair and the second difference coil pair;
acquiring a second voltage difference value array, and acquiring voltage difference value thresholds corresponding to the voltage difference values in the second voltage difference value array to form a second voltage difference value threshold array, wherein the second voltage difference value array is composed of difference values of induction voltages of two second coils in the third difference coil pair and the fourth difference coil pair;
judging whether metal foreign matters exist or not according to the first voltage difference value array, the first voltage difference value threshold array, the second voltage difference value array and the second voltage difference value threshold array;
if so, controlling to interrupt charging to the charging vehicle, and judging the position information of the metal foreign matter according to the first voltage difference value array and/or the second voltage difference value array;
if not, detecting whether the charging vehicle is fully charged or not, and controlling to stop charging the vehicle under the condition that the vehicle is fully charged.
In one embodiment, the processor is further configured to:
acquiring a charging request sent by a charging vehicle;
and controlling to start and detect whether metal foreign matters exist or not according to the charging request.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain drawings of other embodiments based on these drawings without any creative effort.
Fig. 1 is a schematic view of an application scenario of a wireless charging foreign object detection apparatus according to an embodiment of the present application;
fig. 2 is a schematic diagram of an arrangement of a first detection coil unit and a second detection coil unit provided in an embodiment of the present application;
fig. 3 is a schematic circuit architecture diagram of a wireless charging foreign object detection device according to an embodiment of the present application;
fig. 4a is a schematic diagram of an arrangement of first detection coil units provided in an embodiment of the present application;
fig. 4b is a schematic diagram of an arrangement of second detection coil units provided in an embodiment of the present application;
fig. 5 is a schematic circuit architecture diagram of a wireless charging foreign object detection device according to another embodiment of the present application;
fig. 6 is a schematic circuit architecture diagram of a wireless charging foreign object detection device according to another embodiment of the present application.
Detailed Description
To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present application are illustrated in the accompanying drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
Where the terms "comprising," "having," and "including" are used herein, another element may be added unless an explicit limitation is used, such as "only," "consisting of … …," etc. Unless mentioned to the contrary, terms in the singular may include the plural and are not to be construed as being one in number.
It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present application.
Throughout the description of the present application, it is to be noted that, unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; the connection may be direct or indirect via an intermediate medium, and the connection may be internal to the two components. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.
Referring to fig. 1 to 3, in an embodiment of the present application, a wireless charging foreign object detection apparatus is provided, which includes a support plate 10, a first detection coil unit 20 and a second detection coil unit 30, wherein the support plate 10 is placed above a plane where a ground-side power transmission device is located, and a first surface of the support plate 10 is parallel to the plane where the power transmission device is located; the first detection coil unit 20 is disposed on the first surface of the support plate 10, and includes a plurality of first coils 21 arranged along a first direction, such as Ox, for respectively acquiring induced electrical signals of the closed detection coil caused by the magnetic field change between the power transmitting device and the vehicle power receiving end during charging, where the induced electrical signals include induced voltage and/or induced current; the second detection coil unit 30 is arranged on the first surface of the support plate 10, is arranged in a stacked manner with the first detection coil unit 20, and comprises a plurality of second coils 31 arranged along a second direction, such as Oy, and is used for acquiring an induced electric signal of the closing detection coil caused by the change of the magnetic field between the power transmitting device and the vehicle power receiving end in the charging process, the orthographic projection of the second detection coil unit 30 on the first surface is overlapped with the orthographic projection of the first detection coil unit 20 on the first surface, and the center of the overlapped area and the center of the power transmitting device are positioned on a straight line perpendicular to the first surface; the signal acquisition and processing module 40 is respectively connected to the first detection coil unit 20 and the second detection coil unit 30, and is configured to acquire an induced electrical signal of the first detection coil unit 20 to generate a first sampled electrical signal, and acquire an induced electrical signal of the second detection coil unit 30 to generate a second sampled electrical signal; the metal foreign matter judgment circuit 50 is connected to the signal acquisition and processing module 40, and is configured to receive the first sampling electrical signal and the second sampling electrical signal, and judge whether a metal foreign matter exists according to the first sampling electrical signal and the second sampling electrical signal.
By way of example, with continuing reference to fig. 1-3, a support plate 10 is disposed above a plane in which a ground-side power transmitting device is located, and a first surface of the support plate 10 is disposed parallel to the plane in which the power transmitting device is located; then, a first detection coil unit 20 including a plurality of first coils 21 arranged in the first direction Ox is disposed on the first surface of the support plate 10, and a second detection coil unit 30 is disposed in a stacked manner with the first detection coil unit 20, an orthogonal projection of the second detection coil unit 30 on the first surface overlaps an orthogonal projection of the first detection coil unit 20 on the first surface, and a center of an overlapping region and a center of the power transmitting device are located on a straight line perpendicular to the first surface; respectively acquiring induced electrical signals of a closed detection coil caused by magnetic field change between the power transmitting device and a vehicle power receiving end in a charging process by utilizing each first coil 21 in the first detection coil unit 20 and each second coil 31 in the second detection coil unit 30, wherein the induced electrical signals comprise induced voltage and/or induced current; the signal acquisition and processing module 40 is respectively connected to the first detection coil unit 20 and the second detection coil unit 30, and is configured to acquire an induced electrical signal of the first detection coil unit 20 to generate a first sampled electrical signal, and acquire an induced electrical signal of the second detection coil unit 30 to generate a second sampled electrical signal; the metal foreign matter judgment circuit 50 connected with the signal acquisition and processing module 40 judges whether metal foreign matter exists according to the received first sampling electric signal and the second sampling electric signal, so that intelligent detection of the metal foreign matter in a magnetic field coupling space of the wireless charging system is realized, the metal foreign matter is prevented from entering a magnetic field coupling area, eddy current is formed on the metal surface under the influence of an alternating electromagnetic field in the charging process, the temperature of the metal foreign matter is rapidly increased, and inflammable matters such as surrounding weeds and paper scraps are ignited, and safety problems such as fire disaster are caused.
Referring to fig. 4a-4b, in an embodiment of the present application, the first coils 21 are rectangular coils and are even numbers, such as 2m, m is a positive integer, the second coils 31 are rectangular coils and are even numbers, such as 2n, n is a positive integer, the first coils 21 are arranged in a linear array with equal intervals along a first direction Ox, the second coils 31 are arranged in a linear array with equal intervals along a second direction Oy, and the first direction Ox is perpendicular to the second direction Oy; two pairs of first coils at the central portion of the first detection coil unit 20 are paired alternately to form a first difference coil pair, for example, the first coil ma is paired with the first coil (m-1) b to form a first difference coil pair, and the first coil mb is paired with the first coil (m-1) a to form a first difference coil pair. In the first coils of the first detection coil unit 20 except for the first difference coil pair, the first coils located at symmetrical positions form second difference coil pairs, for example, the first coil ia and the first coil ib are paired to form a second difference coil pair, i ∈ [1, m-2], and i is a positive integer. Two pairs of second coils at the central portion of the second detection coil unit 30 are paired in an interleaved manner to form a third difference coil pair, for example, the second coil nc is paired with the second coil (n-1) d to form a third difference coil pair, and the second coil nd is paired with the second coil (n-1) c to form a third difference coil pair. In the second coils of the second detection coil unit 30 except for the third difference-finding coil pair, the second coils located at symmetrical positions form a fourth difference-finding coil pair, for example, the second coil jc and the second coil jd are paired to form a fourth difference-finding coil pair, j ∈ [1, n-2], and j is a positive integer.
Referring to fig. 5, in an embodiment of the present application, the metallic foreign object determination circuit 50 further includes a first difference operation circuit 51, a second difference operation circuit 52 and a processor 53, where the first difference operation circuit 51 is connected to the signal acquisition and processing module 40, and is configured to calculate a difference between induced electrical signals of two first coils in each first difference coil pair and a difference between induced electrical signals of two first coils in the second difference coil pair to form a first difference array; the second difference operation circuit 52 is connected to the signal acquisition and processing module 40, and is configured to calculate a difference between the induced electrical signals of the two second coils in each third difference coil pair and a difference between the induced electrical signals of the two second coils in the fourth difference coil pair to form a second difference array; the signal acquisition and processing module 40 is configured to receive analog signals from the first detection coil unit 20 and the second detection coil unit 30, perform filtering amplification processing and analog-to-digital conversion, and output processed digital signals to a next-stage circuit; the processor 53 is connected to both the first difference operation circuit 51 and the second difference operation circuit 52, and is configured to:
acquiring the first difference value array, and acquiring a difference value reference value corresponding to each difference value in the first difference value array to form a first difference value reference value array;
acquiring the second difference value array, and acquiring a difference value reference value corresponding to each difference value in the second difference value array to form a second difference value reference value array;
and judging whether metal foreign matters exist according to the first difference value array, the first difference value reference value array, the second difference value array and the second difference value reference value array.
In one embodiment, the processor is configured to:
calculating the difference degree of any difference value in the first difference value array, and acquiring a difference value reference value corresponding to the difference value; if the difference degree is larger than or equal to the difference reference value, judging that metal foreign matters exist;
calculating the difference degree of any difference value in the second difference value array, acquiring a difference value reference value corresponding to the difference value, and judging that a metal foreign body exists if the difference degree is greater than or equal to the difference value reference value;
under the condition that the metal foreign body exists, acquiring a code of a first coil or a code of a second coil corresponding to the difference value so as to determine the position of the metal foreign body according to the codes;
for any difference value x and a difference value reference value y corresponding to the difference value x, the difference degree gamma of the difference value x is calculated according to the following formula:
Figure BDA0002805125730000141
in the above embodiment, the obtained foreign object coordinates are easy to position and reliable in accuracy by arranging the induction coils in the Ox direction or the Oy direction at equal intervals. If the induction coils located at the symmetrical positions of the central area are directly paired, a middle area detection blind area can occur, for example, when a metal foreign object with a uniform appearance just falls between the first coil ma and the first coil mb, and the areas of the metal foreign object covered by the two coils are consistent, the two coils can have the same magnetic flux variation, so that the voltage variation is the same, the effective value variation of the coil unit is also consistent, and the coil unit is insensitive to the foreign object. Based on the weak magnetic characteristic of the middle area of the coil, the detection blind area of the middle area of the detection coil can be effectively eliminated through the staggered design on circuit sampling.
Referring to fig. 4a-4b and fig. 5, in one embodiment of the present application, two pairs of first coils of the central portion of the first detection coil unit are symmetrically paired to form a first summing coil pair, for example, the first coil ma is paired with the first coil mb to form a first summing coil pair, and the first coil (m-1) a is paired with the first coil (m-1) b to form a first summing coil pair. Two pairs of second coils at the central portion of the second detection coil unit 30 are symmetrically paired to form a second summing coil pair, for example, the second coil nc is paired with the second coil nd to form a second summing coil pair, and the second coil (n-1) c is paired with the second coil (n-1) d to form a second summing coil pair. The metal foreign matter judgment circuit 50 further comprises a first sum value operation circuit 54 and a second sum value operation circuit 55, wherein the first sum value operation circuit 54 is connected with the signal acquisition and processing module 40 and is used for calculating the sum value of the induced electrical signals of the two first coils in the first sum coil pair to form a first sum value array; the second sum operation circuit 55 is connected to the signal acquisition and processing module 40, and is configured to calculate a sum of the induced electrical signals of the two second coils in the second summation coil pair to form a second sum array; the processor 53 is configured to:
acquiring the first sum value array, and acquiring sum value reference values corresponding to the sum values in the first sum value array to form a first sum value reference value array;
acquiring the second sum value array, and acquiring sum value reference values corresponding to the sum values in the second sum value array to form a second sum value reference value array;
judging whether metal foreign matters exist or not according to the first sum value array, the first sum value reference value array, the second sum value array and the second sum value reference value array;
if any sum value in the first sum value group is smaller than or equal to the corresponding sum value reference value, judging that metal foreign matters exist in the central area of the power transmitting device; and
and if any sum value in the second sum value array is less than or equal to the corresponding sum value reference value, judging that metal foreign matters exist in the central area of the power transmitting device.
In the above embodiment, the first sum operation circuit and the second sum operation circuit are provided, and the first difference operation circuit and the second difference operation circuit are matched to further eliminate the detection blind area and improve the accuracy of the metal foreign matter detection.
In one embodiment of the present application, there is provided an electric vehicle parking assist apparatus for assisting an electric vehicle to be parked for charging, including:
in any of the embodiments of the present application, the processor is further configured to:
in the case where it is determined that there is no metallic foreign object directly above the power transmitting device, the vehicle enters the charging area. Since the offset in the lateral direction is not easily adjustable, there are very likely situations where the vehicle is not perfectly aligned with the charging device. The mutual inductance between the power receiving coil and the detecting coil is calculated by detecting signals such as voltage and current of the power transmitting device and the power receiving device. The idea adopted in the calculation process is as follows: the mutual inductance between the power receiving coil and a certain designated detection coil and the offset distance show a specific corresponding relation, namely the offset condition of the actual vehicle is estimated according to the change trend and the numerical value of the mutual inductance.
As an example, the principle of assisting the electric vehicle to park for charging in the embodiment of the present application is briefly described by taking the first direction as an example when no-load detection does not find a foreign object after charging is requested, and the induced voltage of any one of the first coils in the first direction is obtained when no-load detection does not find a metallic foreign object and the electric vehicle enters the parking space after charging is requested
Figure BDA0002805125730000161
Current I of the transmitting coil of the power transmitting apparatus1Current I of receiving coil of the power receiving device2A mutual inductance value M between the transmission coil of the power transmission device and the first detection coil unitGA-SensorAnd a preset angular frequency value omega, and the mutual inductance value M between the first detection coil unit and the receiving coil of the power receiving device is calculated according to the following formulaVA-Sensor：
Figure BDA0002805125730000162
According to the mutual inductance value MVA-SensorAnd performing comparison operation by using a preset offset-mutual inductance curve to judge the offset condition of the electric vehicle and assist the electric vehicle to stop and align.
Experiments show that in a certain direction, such as a transverse positive direction, the data can be detected in advance through a two-dimensional curve graph of mutual inductance and offset, and the mutual inductance is actually similar to a resistor, is an inherent characteristic and cannot be changed easily. The drawn mutual inductance-offset curve is a unimodal characteristic, real-time mutual inductance of the detection coil and the secondary side is calculated according to some current and voltage quantities, and meanwhile, according to the offset trend of the vehicle, which offset quantity corresponds to the mutual inductance quantity is found on the curve drawn in a pretest mode, so that the offset information of the vehicle can be obtained. For example, there is a corresponding mutual inductance signal value for each offset of the vehicle on one side of the first direction. Because the curve of the offset and the mutual inductance presents a single-peak characteristic, in the real-time detection and calculation process, the situation that one mutual inductance value corresponds to two offsets can be effectively solved according to the ascending or descending of the change trend of the mutual inductance. According to the mutual inductance signal value detected in real time, the mutual inductance signal value is compared with the offset-mutual inductance curve of the pre-measurement, so that the offset condition of the vehicle can be accurately judged, and the vehicle parking alignment is assisted.
Further, in an embodiment of the present application, a mutual inductance value of a first coil in the first detection coil unit is obtained, and a variation trend of the mutual inductance value of the first coil is determined in real time during a moving process of the electric vehicle, so as to determine whether an offset of the electric vehicle in the first direction is greater than or equal to a first preset offset threshold according to the variation trend and the offset-mutual inductance curve, and if so, control to execute a preset warning action; and/or
And acquiring a mutual inductance value of a second coil in the second detection coil unit, judging the change trend of the mutual inductance value of the second coil in real time in the moving process of the electric vehicle, judging whether the offset of the electric vehicle in the second direction is greater than or equal to a second preset offset threshold value according to the change trend and the offset-mutual inductance curve, and if so, controlling to execute a preset warning action.
Specifically, the mutual inductance value of one detection coil unit in the first detection coil may be obtained, the variation trend of the mutual inductance value may be determined in real time during the moving process of the vehicle, and the offset condition of the vehicle in the first direction may be determined by comparing the point correspondence relationship between the mutual inductance value and the mutual inductance value-offset curve in the first direction. Judging whether the offset is greater than or equal to a first preset offset threshold value or not, and if so, controlling to execute a preset warning action; similarly, the mutual inductance value of one detection coil unit in the second detection coil can be acquired, the variation trend of the mutual inductance value is judged in real time in the moving process of the vehicle, the corresponding relation between the mutual inductance value and the mutual inductance value-offset value curve in the second direction is consulted, the offset condition of the vehicle in the second direction is judged, whether the offset is larger than or equal to a second preset offset threshold value or not is judged, and if yes, the preset warning action is controlled to be executed.
Further, in one embodiment of the present application, the processor is further configured to:
acquiring a mutual inductance value M between the first detection coil unit and a reception coil of the power reception deviceVA-Sensor；
Obtaining the real-time current value I of the transmitting coil of the power transmitting device under the condition that the vehicle deviates1-realtimeAnd a receiving line of the power receiving deviceReal-time current value I of loop2-realtimeThe power transmitting device and the power receiving device sense the induced voltage U on the coilTargetInduced voltage U of the coil is detected at a symmetrical positionTargetSubtracting to obtain the voltage deviation U introduced by the offsetRemove. According to the voltage self-zeroing scheme, the voltage difference semaphore detected on the coil pair is detected in real time, and the calculated voltage semaphore U generated due to offset is subtractedRemoveTo obtain the voltage U generated on the detection coil due to the existence of metal foreign mattersMetal-Sensor；
By comparing the voltage U generated on the detection coil due to the presence of metallic foreign matterMetal-SensorAnd the difference value reference value to judge whether metal foreign matters exist or not and determine the positions of the metal foreign matters, and the induced voltage U of the receiving coil of the power transmitting deviceTargetCalculated according to the following formula:
Figure BDA0002805125730000181
in one embodiment of the present application, the warning action includes at least one of controlling to stop charging, sending a warning message or sending a vehicle body deviation message.
Further, in one embodiment of the present application, the processor is further configured to:
after controlling to execute a preset offset self-zero procedure, controlling to start charging the charging vehicle;
acquiring a first voltage difference value array, and acquiring voltage difference value thresholds corresponding to the voltage difference values in the first voltage difference value array to form a first voltage difference value threshold array, wherein the first voltage difference value array is composed of difference values of induction voltages of two first coils in the first difference coil pair and the second difference coil pair;
acquiring a second voltage difference value array, and acquiring voltage difference value thresholds corresponding to the voltage difference values in the second voltage difference value array to form a second voltage difference value threshold array, wherein the second voltage difference value array is composed of difference values of induction voltages of two second coils in the third difference coil pair and the fourth difference coil pair;
judging whether metal foreign matters exist or not according to the first voltage difference value array, the first voltage difference value threshold array, the second voltage difference value array and the second voltage difference value threshold array;
if so, controlling to interrupt charging to the charging vehicle, and judging the position information of the metal foreign matter according to the first voltage difference value array and/or the second voltage difference value array;
if not, detecting whether the charging vehicle is fully charged or not, and controlling to stop charging the vehicle under the condition that the vehicle is fully charged.
Further, in one embodiment of the present application, the processor is further configured to:
acquiring a charging request sent by a charging vehicle;
and controlling to start and detect whether metal foreign matters exist or not according to the charging request.
As an example, in an embodiment of the present application, when a vehicle does not enter a charging parking space, the vehicle may first query, through the in-vehicle smart charging client, a nearby smart charging parking space in an idle state, and send a parking charging request to the idle parking space. After the intelligent charging parking space control terminal receives the charging request, the system is firstly electrified to detect the system function and the metal foreign matter on the ground surface, and whether the metal foreign matter exists or not, the shape of the metal foreign matter and the position of the metal foreign matter are judged. The occurrence of the metal foreign matters can simultaneously influence the induced voltage quantity of the horizontal and vertical coils at the positions, and the induced voltage quantity of the horizontal and vertical coils is detected, so that the position of the foreign matters in the area where the planes of the coils are located and the approximate shape of the foreign matters can be obtained. If the self-checking of each module of the system is passed and no metal foreign matter exists, the intelligent charging system sends a request reply to the vehicle owner to inform that the intelligent charging state is good and allows parking and charging; if each module self-checking of system passes and detects that there is the metallic foreign matter on the ground surface, assesses through detection algorithm that foreign matter danger level is unsatisfactory, may bring great power loss or may cause local high temperature for the charging process, and intelligence charging position will collect the information of foreign matter, sends information to vehicle cab through the LAN, informs that the charged state on the car owner intelligence charging position is unsatisfied with the requirement, lights the warning light and before danger source clears away the wireless function of charging of system's not opening. The system informs personnel to actively remove the foreign matters or remove the foreign matters by means of an intelligent cleaning mechanical structure, and after the danger source is removed, the vehicle can be normally charged in the parking space.
After the above process is completed, the vehicle enters the intelligent charging parking space. Because the audience group of the current intelligent parking service is small, most of the intelligent parking service is operated by the traditional hands, and the parked vehicles are easily not completely aligned with the ground charging area in space due to uneven individual driving technical level in the operation process. Researches find that the spatial position offset of the ground wireless charging transmitting terminal and the vehicle wireless receiving terminal easily causes the reduction of the magnetic field coupling capacity between the transmitting terminal and the receiving terminal, directly causes the increase of magnetic leakage and the great reduction of transmission power, and can also cause the increase of heat loss of the transmitting terminal and the receiving terminal, and further reduces the energy transmission efficiency of the system. In order to solve the problem, a vehicle auxiliary alignment device is designed in space to help a vehicle owner to complete parking alignment more simply and efficiently, and the device is an important link for realizing marketization, standardization and safety of the wireless charging technology of the vehicle. In general, in the parking process of a vehicle, the position adjustment in the front-rear direction is relatively simple, and most parking auxiliary systems do not take the offset in the front-rear direction as the key point of the offset detection; and the horizontal region of parking stall is comparatively narrow, is difficult for adjusting when the lateral position skew takes place for the vehicle. However, in the actual situation, a certain mechanical error exists in the production process of the equipment, and even though the parking assisting device helps the driver to judge the direction and carry out the parking alignment process, the ground power transmitting device and the vehicle receiving device are difficult to be aligned completely.
Specifically, referring to fig. 4a, after the no-load foreign object detection link is performed, no foreign object exists on the surface of the primary side power transmission device on the ground side, and the vehicle enters the parking space. Since the offset in the lateral direction is not easily adjustable, there are very likely situations where the vehicle is not perfectly aligned with the charging device. Taking the transverse detection coil as an example, the mutual inductance between the power receiving coil and the detection coil is calculated by detecting signals such as voltage and current of the power transmitting device and the power receiving device. The mutual inductance between the power receiving coil and a certain designated detection coil and the offset distance present a specific corresponding relation, namely the offset condition of the actual vehicle can be deduced according to the change trend and the numerical value of the mutual inductance. The lateral deviation information of the vehicle is deduced by comparing the mutual inductance values of a plurality of groups of detection coils and power receiving coils with the mutual inductance values of the detection coils and the power receiving coils tested in an off-line (pre-) mode, and the information is packaged and transmitted to a vehicle control room in real time through a local area network after the ground section obtains the deviation information of the vehicle, so that a driver can conveniently calibrate the parking position by observing the deviation information.
The foreign matter detection in the system offset state specifically means that after a vehicle offset detection process, a vehicle stops on a parking space requested to be charged, the vehicle offset amount in the transverse and longitudinal directions is within a national standard allowable range, no foreign matter exists on the ground side after no-load foreign matter detection and removal, and at the moment, the wireless charging process of the vehicle is started on the ground side. According to the regulation of national standard GB/T38775.3-2020, the allowable offset range of the primary side equipment and the secondary side equipment of the vehicle wireless charging system is +/-75 mm in the transverse direction and +/-100 mm in the longitudinal direction, and when the offset is larger than the range, the coupling condition of a charging magnetic field is poor, and the charging power loss is large. In the charging process, foreign metal foreign matters may enter a magnetic field coupling region for some reasons, such as a cigarette case (containing aluminum foil), a key, a pop can and the like, and the entry of the foreign matters causes additional loss of charging power and potential safety hazards such as high-temperature combustion and the like caused by vortex heating, so that when a charging facility detects abnormal charging, the charging process should be stopped in time, and the charging process is restarted after a danger source is eliminated. Specifically, the auxiliary coil panel is placed on the upper surface of the ground power transmission device, and the induced voltage on the auxiliary coil is derived from the combined action of the ground power transmission device, the vehicle receiving device and the metal foreign matter. Since the distance between the auxiliary coil and the ground power transmission device is small, the mutual inductance of the offset of the vehicle to the auxiliary coil and the ground power transmission device variesThe influence of the transformation is small, and the influence is ignored in the calculation process. The mutual inductance change of the vehicle receiving device and the ground transmitting device can be caused by the position offset of the vehicle receiving device and the ground transmitting device. The mutual inductance quantity can be different along with the deviation of the vehicle, and research shows that the two-dimensional image of the mutual inductance and the deviation has unimodal characteristics within the range of +/-75 mm of transverse deviation quantity. According to this feature, the mutual inductance between the power transmitting device and the vehicle receiving device and the auxiliary coil is measured in advance by signals such as voltage and current in an off-line state, and the amount of induced voltage U generated by the power transmitting device and the power receiving device on a specified detection coil can be calculated by measuring the mutual inductance between the specified detection coil and the power receiving device, the current of the power receiving device, and the current amount of the power transmitting device in an off-line test in a real-time parking stateTargetSymmetrical position detection of the voltage difference U due to offset on the coilRemove. Detecting the total voltage difference of the specified detection coil pair under the real-time condition, and subtracting the URemoveThe voltage fluctuation caused by the deviation and not caused by the foreign matters is eliminated, and the voltage difference caused by the foreign matters can be measured more accurately. The coordinate position detection of the metal foreign body and the approximate outline size of the foreign body under the condition are consistent with the detection principle of the metal foreign body under the no-load state.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1. A wireless foreign matter detection device that charges, characterized by includes:
the supporting plate is placed above a plane where the ground-side power transmitting device is located, and a first surface of the supporting plate is parallel to the plane where the power transmitting device is located;
the first detection coil unit is arranged on the first surface of the supporting plate, comprises a plurality of first coils arranged along a first direction and is used for respectively acquiring induced electric signals of the closed detection coil caused by the change of a magnetic field between the power transmitting device and a vehicle power receiving end in the charging process, and the induced electric signals comprise induced voltage and/or induced current;
the second detection coil unit is arranged on the first surface, is stacked with the first detection coil unit, comprises a plurality of second coils arranged along a second direction and is used for acquiring the induced electrical signals, the orthographic projection of the second detection coil unit on the first surface is overlapped with the orthographic projection of the first detection coil unit on the first surface, and the center of the overlapped area and the center of the power transmitting device are positioned on a straight line perpendicular to the first surface;
the signal acquisition and processing module is respectively connected with the first detection coil unit and the second detection coil unit and is used for acquiring the induced electrical signal of the first detection coil unit to generate a first sampling electrical signal and acquiring the induced electrical signal of the second detection coil unit to generate a second sampling electrical signal;
the metal foreign matter judgment circuit is connected with the signal acquisition and processing module and used for receiving the first sampling electrical signal and the second sampling electrical signal and judging whether metal foreign matters exist or not according to the first sampling electrical signal and the second sampling electrical signal;
the first coils are rectangular coils and are even in number, the second coils are rectangular coils and are even in number, the first coils are arranged in an equidistant linear array along the first direction, the second coils are arranged in an equidistant linear array along the second direction, and the first direction is perpendicular to the second direction;
two pairs of first coils at the central part of the first detection coil unit are paired in a staggered mode to form a first difference-finding coil pair respectively;
in the first coils except the first difference-finding coil pair in the first detection coil unit, the first coils at symmetrical positions form second difference-finding coil pairs respectively;
two pairs of second coils at the central part of the second detection coil unit are paired in a staggered mode to form a third difference-finding coil pair respectively;
in the second detection coil unit, in addition to the third difference-finding coil pair, second coils located at symmetrical positions form fourth difference-finding coil pairs respectively;
the metal foreign matter judgment circuit further comprises a first difference value operation circuit, a second difference value operation circuit and a processor;
the first difference operation circuit is connected with each first difference coil pair and each second difference coil pair and is used for calculating the difference of the induced electric signals of the two first coils in each first difference coil pair and the difference of the induced electric signals of the two first coils in the second difference coil pair to form a first difference array;
the second difference operation circuit is connected with each third difference coil pair and each fourth difference coil pair, and is used for calculating the difference of the induced electrical signals of the two second coils in each third difference coil pair and the difference of the induced electrical signals of the two second coils in the fourth difference coil pair to form a second difference array;
the processor is connected to both the first difference operation circuit and the second difference operation circuit, and is configured to:
acquiring the first difference value array, and acquiring a difference value reference value corresponding to each difference value in the first difference value array to form a first difference value reference value array;
acquiring the second difference value array, and acquiring a difference value reference value corresponding to each difference value in the second difference value array to form a second difference value reference value array;
and judging whether metal foreign matters exist according to the first difference value array, the first difference value reference value array, the second difference value array and the second difference value reference value array.
2. The apparatus of claim 1, wherein the processor is configured to:
acquiring a charging request sent by a charging vehicle;
and controlling to start and detect whether metal foreign matters exist or not according to the charging request.
3. The apparatus of claim 2, wherein the processor is configured to:
calculating the difference degree of any difference value in the first difference value array, and acquiring a difference value reference value corresponding to the difference value; if the difference degree is larger than or equal to the difference reference value, judging that metal foreign matters exist;
calculating the difference degree of any difference value in the second difference value array, acquiring a difference value reference value corresponding to the difference value, and judging that metal foreign matters exist if the difference degree is greater than or equal to the difference value reference value;
under the condition that the metal foreign body exists, acquiring a code of a first coil or a code of a second coil corresponding to the difference value so as to determine the position of the metal foreign body according to the codes;
for any difference value x and the difference reference value y corresponding to the difference value x, the difference degree γ of the difference value x is calculated according to the following formula:
Figure FDA0003420058770000031
4. the apparatus according to claim 2 or 3, wherein two pairs of first coils of a central portion of the first detection coil unit are symmetrically paired to form a pair of first summing coils, respectively; two pairs of second coils at the central part of the second detection coil unit are symmetrically paired to form a second summation coil pair respectively;
the metal foreign matter judgment circuit further comprises a first sum operation circuit and a second sum operation circuit;
the first sum operation circuit is connected with the first summing coil pair and the processor and is used for calculating the sum of the induced electric signals of two first coils in the first summing coil pair to form a first sum array;
the second sum operation circuit is connected with the second summing coil pair and the processor and is used for calculating the sum of the induced electric signals of the two second coils in the second summing coil pair to form a second sum array;
the processor is configured to:
acquiring the first sum value array, and acquiring sum value reference values corresponding to the sum values in the first sum value array to form a first sum value reference value array;
acquiring the second sum value array, and acquiring sum value reference values corresponding to the sum values in the second sum value array to form a second sum value reference value array;
judging whether metal foreign matters exist according to the first sum value array, the first sum value reference value array, the second sum value array and the second sum value reference value array;
if any sum value in the first sum value group is smaller than or equal to the corresponding sum value reference value, judging that metal foreign matters exist in the central area of the power transmitting device; and
and if any sum value in the second sum value array is less than or equal to the corresponding sum value reference value, judging that metal foreign matters exist in the central area of the power transmitting device.
5. An electric vehicle parking assist apparatus for assisting an electric vehicle to park for charging, comprising:
the wireless charging foreign object detection device of any of claims 2-4, the processor configured to:
empty after requesting chargingAcquiring the induced voltage of any one first coil in the first direction under the condition that no metal foreign matter is found in the load detection and the electric vehicle enters a parking space
Figure FDA0003420058770000041
Current I of the transmitting coil of the power transmitting apparatus1Current I of receiving coil of power receiving device2A mutual inductance value M between the transmission coil of the power transmission device and the first detection coil unitGA-SensorAnd a preset angular frequency value omega, and the mutual inductance value M between the first detection coil unit and the receiving coil of the power receiving device is calculated according to the following formulaVA-Sensor：
Figure FDA0003420058770000042
According to the mutual inductance value MVA-SensorAnd performing comparison operation by using a preset offset-mutual inductance curve to judge the offset condition of the electric vehicle and assist the electric vehicle to stop and align.
6. The apparatus of claim 5, wherein the processor is further configured to:
acquiring a mutual inductance value of a first coil in the first detection coil unit, and judging the change trend of the mutual inductance value of the first coil in real time in the moving process of the electric vehicle, so as to judge whether the offset of the electric vehicle in the first direction is greater than or equal to a first preset offset threshold value or not according to the change trend and the offset-mutual inductance curve, and if so, controlling to execute a preset warning action; and/or
And acquiring a mutual inductance value of a second coil in the second detection coil unit, judging the change trend of the mutual inductance value of the second coil in real time in the moving process of the electric vehicle, judging whether the offset of the electric vehicle in the second direction is greater than or equal to a second preset offset threshold value according to the change trend and the offset-mutual inductance curve, and if so, controlling to execute a preset warning action.
7. The apparatus of claim 6, wherein the processor is further configured to:
acquiring a mutual inductance value M between the first detection coil unit and a reception coil of the power reception deviceVA-Sensor；
Obtaining the real-time current value I of the transmitting coil of the power transmitting device under the condition that the vehicle deviates1-realtimeA real-time current value I of a receiving coil of the power receiving device2-realtimeThe power transmitting device and the power receiving device sense the induced voltage U on the coilTargetInduced voltage U of the coil is detected symmetricallyTargetSubtracting to obtain the voltage deviation U introduced by the offsetRemoveAccording to the voltage self-zeroing scheme, the voltage difference semaphore detected on the coil pair is detected in real time, and the calculated voltage semaphore U generated due to offset is subtractedRemoveTo obtain the voltage U generated on the detection coil only due to the existence of metal foreign mattersMetal-Sensor；
By comparing the voltage U generated on the detection coil due to the presence of metallic foreign matterMetal-SensorAnd the difference value reference value to judge whether metal foreign matters exist or not and determine the positions of the metal foreign matters, and the induced voltage U of the power transmitting device and the power receiving device on the detection coilTargetCalculated according to the following formula:
Figure FDA0003420058770000061
8. the device of claim 6 or 7, wherein the alert action comprises at least one of controlling a stop of charging, issuing a warning message, or issuing a body-offset message.
9. The apparatus of any of claims 5-7, wherein the processor is further configured to:
after controlling to execute a preset offset self-zero procedure, controlling to start charging the charging vehicle;
acquiring a first voltage difference value array, and acquiring voltage difference value thresholds corresponding to the voltage difference values in the first voltage difference value array to form a first voltage difference value threshold array, wherein the first voltage difference value array is composed of difference values of induction voltages of two first coils in the first difference coil pair and the second difference coil pair;
acquiring a second voltage difference value array, and acquiring voltage difference value thresholds corresponding to the voltage difference values in the second voltage difference value array to form a second voltage difference value threshold array, wherein the second voltage difference value array is composed of difference values of induction voltages of two second coils in the third difference coil pair and the fourth difference coil pair;
judging whether metal foreign matters exist or not according to the first voltage difference value array, the first voltage difference value threshold array, the second voltage difference value array and the second voltage difference value threshold array;
if so, controlling to interrupt charging to the charging vehicle, and judging the position information of the metal foreign matter according to the first voltage difference value array and/or the second voltage difference value array;
if not, detecting whether the charging vehicle is fully charged or not, and controlling to stop charging the vehicle under the condition that the vehicle is fully charged.
10. The apparatus of any of claims 5-7, wherein the processor is further configured to:
acquiring a charging request sent by a charging vehicle;
and controlling to start and detect whether metal foreign matters exist or not according to the charging request.
CN202011364909.7A 2020-11-27 2020-11-27 Wireless charging foreign matter detection device and electric vehicle parking auxiliary device Active CN112550009B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202011364909.7A CN112550009B (en) 2020-11-27 2020-11-27 Wireless charging foreign matter detection device and electric vehicle parking auxiliary device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011364909.7A CN112550009B (en) 2020-11-27 2020-11-27 Wireless charging foreign matter detection device and electric vehicle parking auxiliary device

Publications (2)

Publication Number Publication Date
CN112550009A CN112550009A (en) 2021-03-26
CN112550009B true CN112550009B (en) 2022-05-13

Family

ID=75046527

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011364909.7A Active CN112550009B (en) 2020-11-27 2020-11-27 Wireless charging foreign matter detection device and electric vehicle parking auxiliary device

Country Status (1)

Country Link
CN (1) CN112550009B (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113199948A (en) * 2021-05-26 2021-08-03 大连海事大学 Wireless charging detection device
CN113895251B (en) * 2021-09-01 2024-02-13 上海酷充电子科技有限公司 Foreign matter detection circuit and method of wireless charging system of electric automobile
CN115201618B (en) * 2022-09-19 2023-03-24 中汽研新能源汽车检验中心(天津)有限公司 Electric automobile wireless charging auxiliary function test system

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102543229A (en) * 2012-02-08 2012-07-04 上海昱章电气成套设备有限公司 Nuclear electric rod position measurement device based on single coils and difference value measurement method of nuclear power rod position thereof
JP2015104161A (en) * 2013-11-21 2015-06-04 トヨタ自動車株式会社 Non-contact power transmission device and non-contact power transmission system
JP6164365B2 (en) * 2014-04-08 2017-07-19 日産自動車株式会社 Non-contact power supply coil
CN205720715U (en) * 2016-04-18 2016-11-23 中兴新能源汽车有限责任公司 Detection device of metal foreign body, judgment means and wireless charging system
CN106560730B (en) * 2016-04-18 2019-03-26 中兴新能源汽车有限责任公司 Detection device of metal foreign body, detection method, judgment means and wireless charging system
CN107070003B (en) * 2017-04-07 2019-06-28 湖南大学 For the detection device of metal foreign body of wireless power transmission, method and Transmission system
CN109001821B (en) * 2018-04-16 2020-11-17 上海交通大学 High-precision foreign matter detection system and method in wireless power transmission system
KR102067586B1 (en) * 2018-04-26 2020-01-17 광주과학기술원 Foreign object detection system and operating method thereof
CN108725239B (en) * 2018-05-03 2022-04-01 中国第一汽车股份有限公司 Alignment device and method for wireless charging of electric automobile
CN109038850B (en) * 2018-06-25 2020-07-24 华为技术有限公司 Device, equipment and method for detecting metal foreign matters in wireless charging system
KR102397707B1 (en) * 2018-11-15 2022-05-13 르노코리아자동차 주식회사 Electric vehicle including small metal removal device, and control method thereof
CN109808520B (en) * 2019-01-28 2021-02-09 许继电源有限公司 Electric vehicle wireless charging foreign matter and position detection method
CN111431254A (en) * 2019-06-30 2020-07-17 比亚迪股份有限公司 Charging control method and device, circuit topology, energy conversion device and vehicle
CN111580171B (en) * 2020-06-04 2021-09-28 山东大学 Metal object detection device and method

Also Published As

Publication number Publication date
CN112550009A (en) 2021-03-26

Similar Documents

Publication Publication Date Title
CN112550009B (en) Wireless charging foreign matter detection device and electric vehicle parking auxiliary device
RU2554103C1 (en) Non-contact power supply device
CN103563215B (en) Contactless power supply device
KR101887738B1 (en) Alignment method for wireless power transfer coil and apparatus using the same
US10562396B2 (en) Parking assistance apparatus and system
KR102550114B1 (en) Coil alignment method and wireless power transfer apparatus using the same for electric vehicles
US9631950B2 (en) Method and apparatus for aligning a vehicle with an inductive charging system
JP5658592B2 (en) Non-contact power feeding device for moving objects
CN107612157B (en) Vehicle wireless power transmission system with performance monitoring and monitoring method thereof
US9260026B2 (en) Vehicle to wireless power transfer coupling coil alignment sensor
US20190140481A1 (en) Surface flux control for inductive wireless charging systems
CN102971939A (en) Voltage detector, abnormality detection device, non-contact power transfer device, non-contact power receiver device, and vehicle
WO2018132209A1 (en) Foreign object detection using heat sensitive material and inductive sensing
US20140239735A1 (en) Contactless power transfer system for movable object
EP3398804B1 (en) Inductive power transfer for transferring electric energy to a vehicle
JP2011160653A (en) System and method of energy transfer for mobile vehicle
US20130021168A1 (en) Wireless power transfer electric vehicle supply equipment installation and validation tool
KR20180081709A (en) System and method for determining relative position and / or orientation between primary and secondary winding structures
US10065515B2 (en) System for wirelessly supplying power during moving
CN106560674A (en) Charging coil position detecting device, coil offset detection method and device, infrastructure end, and vehicle-mounted end
CN207442545U (en) A kind of alignment guidance device and the induction charging system that alignment guidance can be carried out
TW201729511A (en) Method for operating a monitoring apparatus for monitoring an inductive energy transmission apparatus
Son et al. Foreign object detection of wireless power transfer system using sensor coil
Nutwong et al. Position detection with online monitoring system for wireless charging of electric vehicles
US20200254894A1 (en) Method for operating an inductive transmission device

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant