WO2011045883A1

WO2011045883A1 - Road-powered inductive charging system for electric vehicle

Info

Publication number: WO2011045883A1
Application number: PCT/JP2010/004938
Authority: WO
Inventors: Shouichi Tanaka
Original assignee: Three Eye Co., Ltd.
Priority date: 2009-10-13
Filing date: 2010-08-05
Publication date: 2011-04-21

Abstract

It is an object of the invention to provide a road-powered inductive charging system for the EV. A primary core disposed on the surface of a roadway including a parking zone has a pair of a front plate core and a rear plate core extending opposite sides of a longitudinal direction of the roadway. A secondary core disposed on the bottom of the EV has a pair of a front arm core and a rear arm core, which moves in a vertical direction of the EV. Further, a pair of the arm cores has a plate core extending a lateral direction of the EV respectively. Furthermore, the EV battery has a plurality of cells with a bended surface, for example a corrugate shape.

Description

ROAD-POWERED INDUCTIVE CHARGING SYSTEM FOR ELECTRIC VEHICLE

Background of Invention

1. Field of the Invention
The present invention relates to an inductive charging system for an electric vehicle (EV), in particular, a road-powered inductive rapid-charging system for the EV.

2. Description of the Related Art
The EV can save mega cities on the present world from the carbon oxide pollution, the exhaust gas pollution, the heat pollution and the sound pollution, if a weight and price of an EV battery can be reduced largely. Automatic EV-charging from a roadway does not require a large battery. Fortunately, many cars often stop at intersections and parking zones in the present real mega cities. The EV battery can be charged frequently from the roadway including the parking zone, when the automatic charging is available. The well-known inductive charging is preferable for the automatic EV-charging. A transmission efficiency and of the inductive charging is enough, when a primary core and a secondary core are connected inductively well each other. Magnet flux cross-linked to both of the primary coil and the secondary coil is increased by employing the soft magnet cores, because the cores concentrate the magnet flux. However, the serious problem is well-known that the transmission efficiency and transmitting power are decreased largely by increasing of a vertical gap and a horizontal position difference between the two cores.

Vertical moving of the secondary core of the EV is proposed for reducing the vertical gap. Japan Unexamined Patent Publication 1993/111168 proposes a screw mechanism moving the secondary core upward and downward. Japan Unexamined Patent Publication 2000/92615 proposes a three-dimensional robot arm moving the primary core in the three-dimensional space.

However, the prior vertically-moving of the secondary core has problems explained below. First, the secondary coil has a high voltage and a large current, for example 500V and 100A. Accordingly, the secondary coil fixed on the moving secondary core must be connected to a pair of moving cables connecting to the EV battery via the rectifier. The moving cable reduces reliability of the EV-charging system. Next, the prior vertical moving apparatus does not decrease the horizontal position difference between the two cores. Accordingly, it is difficult to improve the power transmission efficiency, even though the secondary core can move vertically. The secondary coil wound on the secondary core can be moved in the three-dimensional space for reducing both of the vertical gap and the horizontal position difference.

However, the three-dimensional-moving apparatus disposed on the EV increases the cost and the weight of the EV largely. After all, the road-powered inductive charging system for the stopping EV is still difficult to construct economically by means of employing the present prior arts.

Another problem is in the EV battery. A life of the EV battery with small charging capability is shortened by the rapid and frequent charging and discharging. Japan Unexamined Patent Publication 2005-243,274 describes that the charging and the discharging of the cell generates a partial expansion difference between the collector and the activity material layer. Further, it describes that the difference of the expansion and the shrinkage produces the torsion in the electrode assembly. Furthermore, it describes linear projections projecting inside from the inner surface of the flat case to restrain the above torsion. The linear projections of the flat case have the square-shaped cross-section. However, it is not easy to make the linear projections on the case. The sharp corner portion of the square-shaped linear projections gives the crack to the activity material layer of the electrode assembly.

Japan Unexamined Patent Publication 1993/111,168 Japan Unexamined Patent Publication 2000/92,615 Japan Unexamined Patent Publication 2005/243,274

It is an object of the invention to provide a road-powered inductive charging system for the EV with excellent power transmission efficiency. Another object is to provide a road-powered inductive charging system for the EV with easy operation. It is another object of the invention to provide a long-life-battery capable of quick-charging frequently. The road-powered inductive charging system of the present invention can be employed at the roadway including a parking zone. In the other words, the roadway includes the parking zone at which the EV is parking.

According of an aspect of the present invention, transmitter (550) disposed in a roadway (7000) including a parking zone connects inductively to receiver (650) disposed on the electric vehicle. Secondary core (611) has a center core (6114) and a pair of moving cores (6111, 6112, 6116 and 6117). Secondary coil (606) is wound around the center core (6114) fixed to a bottom of the electric vehicle. Moving cores (6111, 6112, 6116 and 6117) move downward from a bottom of the electric vehicle in order to connecting inductively primary coil (506) and secondary coil (606).

Accordingly, secondary coil (606) and primary coil (506) can be connected inductively with an excellent mutual inductance, because the moving cores (6111, 6112, 6116 and 6117) are swung downward and comes into contact with the primary core (511) disposed at an upper surface on the roadway. A switching loss of an oscillator and a rectifier is reduced. Further, a copper loss and an iron loss of the transmitter and the receiver are reduced. Furthermore, the cable extending from secondary coil (606) becomes short and does not need to move.

According to a preferred embodiment, the moving cores (6111,6112, 6116 and 6117) has a front moving core (6111, 6116) and a rear moving core (6112, 6117). Center core (6114) extends to a longitudinal direction of the electric vehicle. Front moving core (6111) is adjacent to a front portion of the center core (6114). Rear moving core (6112) is adjacent to a rear portion of the center core (6114). As the result, it is easy to reduce the mutual inductance, because secondary core (611) can have a C-shape magnetic flux passage, when the moving cores are moved downward.

According to another preferred embodiment, front arm core (6111) and rear moving core (6112) are swung around rotation points near the center core (6114). As the result, arm cores (6111, 6112) can be moved downward/upward easily. Further, arm cores (6111, 6112) can be accommodated in the EV after charging, because arm cores (6111, 6112) can extend to the longitudinal direction along a bottom of the EV. In the other words, the EV does not need to make a large room for accommodating the swinging arm cores.

According to another preferred embodiment, a front plate core (6116) and a rear plate core (6117) are supported rotatably to a top portion of the arm cores (6111, 6112). The plate cores (6116, 6117) extend horizontally to the lateral direction, the left/right direction. As the result, the secondary core can face the primary core, even though the EV moves to the left/right direction, the lateral direction.

According to another preferred embodiment, a front plate core (7002) extends forward from a front portion of the center core (7001) of the primary core (511) along an upper surface of the roadway. A rear plate core (7003) extends backward from a rear portion of the center core (7001) of the primary core (511) along an upper surface of the roadway. As the result, the secondary core can face the primary core, even though the EV moves to the forward/rear direction, the longitudinal direction.

According to another preferred embodiment, the center core (7001), the front plate core (7002) and the rear plate core (7003) of the primary core (511) extend to one line to the longitudinal direction of the roadway. As the result, a leakage inductance of the primary coil is decreased, because two longitudinal plate cores (7002, 7003) are apart each other to the longitudinal direction.

According to another preferred embodiment, Wall cores (7004, 7005) extending vertically connect center core (7001) of primary core (511) to plate cores (7002, 7003). As the result, primary coil 506 can be protected from influence of mechanical vibration of the road surface.

According to another preferred embodiment, center core (7001) is made of a column-shaped core having a circle-shaped vertical cross-section. As the result, a total length of the primary coil is reduced.

According to another preferred embodiment, plate cores (7002, 7003) of primary core (511) have a pair of road core portions made (7020, 7030) from soft magnetic powder mixed in road material. As the result, cost of the primary core is reduced without increasing of the copper loss of the primary coil.

According to another preferred embodiment, plate cores (7002, 7003) exposed on the ground surface of the roadway has nearly equal average value of a friction coefficient to the ground surface of the road way. As the result, a vertical air gap between the two cores is reduced largely without slipping of the wheels of the vehicles.

According to another preferred embodiment, the plate cores of the primary core are independent from the center core of the primary core. The plate cores can have tile-shaped member. Accordingly, it is possible to change only the plate cores without changing the center core of the primary core. Preferably, the plate cores of the primary core have a lateral width being more than double of a vertical thickness. Accordingly, the magnetic resistance between the two cores is reduced.

According to another preferred embodiment, moving cores (6111, 6112, 6116 and 6117) are moved upward in accordance with a received traffic signal, when the stopping electric vehicle is charged from the transmitter (550) disposed near an intersection of the roadway. After all, the EV can start quickly at the intersection of the roadway.

According to another preferred embodiment, primary core (511) is on a circuit box (711) accommodating an oscillator supplying a primary current to the primary coil (506). Circuit box (711) is connected to a cable conduit (712) extending to the longitudinal direction. As the result, an electromagnetic noise radiated from power lines connected the oscillator and the primary coil is reduced. Further, the primary coil can be connected to the oscillator correctly, because the primary core with the primary coil is set on the circuit box accommodating the oscillator.

According to another preferred embodiment, the electric vehicle has a sensor detecting an information related a distance between the sensor and the transmitter. As the result, the EV can be stopped a preferred position by using a simple system. For example, traction motor of the running EV can be stopped in accordance with the information automatically.

According to another preferred embodiment, a detecting circuit (6062, 6063) detects an impedance of a pick-up coil (6060) wound around center core (6114) of secondary core (611). As the result, the position of the primary core can be detected easily and correctly.

According to another preferred embodiment, the battery (100) has a plurality of cells (102) arranged in a thickness direction. The cell (102) has two major side walls (103A, 103B) across an electrode assembly accommodated in a cell case (103) of the cell (102). One of said two major side walls (103A, 103B) has at least one of a convex surface. The other one of the two major side walls (103A, 103B) has at least one concave surface. As the results, the cycle life of the battery is improved. This battery of the embodiment can be employed by the other EV without the aspect described above, too.

According to another preferred embodiment, the convex surface of the major side wall (103A) of one cell (102) is adjacent to the concave surface of the major side wall (103B) of another cell (102). A small gap (G) between the convex surface and the concave surface being adjacent each other forms a cooling passage in which cooling fluid flows. Accordingly, the cycle life of the battery is improved.

According to another preferred embodiment, the concave surface and the convex surface of the cells (102) are curved in the width direction and the thickness direction of the cell (102). The concave surface and the convex surface extend straightly to the length direction of the cell (102). As the result, a production process becomes simple.

According to another preferred embodiment, the electrode assembly has a sheet-shaped electrode pair having a sheet-shaped anode (104A) and a sheet-shaped cathode (104B) across a sheet-shaped separator (104C). The sheet-shaped anode (104A) and the sheet-shaped cathode (104B) consist of a sheet-shaped collector (104AB, 104BA) and both of activity material layers (104AA, 104BB) adhered on both major surfaces of the collector (104AB, 104BA). The major surfaces of the collector (104AB, 104BA) and the activity material layers (104AA, 104BB) are curved together along the bended major side walls (103A, 103B). Accordingly, the cycle life of the battery is improved.

According to another preferred embodiment, the major surfaces of the collector and the activity material layers have a corrugate shape. The two major sidewalls of the cell case have a corrugated shape. Accordingly, the cycle life of the battery is improved.

Figure 1 is a vertical cross-section showing schematically a longitudinal view of a road-powered inductive EV-charging system of an embodiment 1. Figure 2 is a schematic plan view showing the system shown in Figure 1. Figure 3 is a vertical cross-section showing schematically a lateral view of the system shown in Figures 1 and 2. Figure 4 is a vertical cross-section showing schematically a longitudinal view of a road-powered inductive EV-charging system of an arrangement of the embodiment 1. Figure 5 is a vertical cross-section showing schematically a lateral view of the system shown in Figures 4. Figure 6 is a vertical cross-section showing schematically a lateral view of the system shown in Figures 4. Figure 7 is a vertical cross-section showing schematically a longitudinal view of an arranged transmitter of the embodiment 1. Figure 8 is a plan view showing an intersection of a roadway on which the system of the embodiment 1 is arranged. Figure 9 is an enlarged plan view showing the system showing a transmitter and a guide line, which is arranged on the roadway. Figure 10 is a vertical cross-section of the guide line shown in Figure 9. Figure 11 is a schematic block diagram of position-detecting circuit with a pick-up coil wound around the secondary core supported by the EV. Figure 12 is a flow chart explaining operation of the position-detecting circuit shown in Figure 11. Figure 13 is a vertical cross-section showing schematically a lateral view of another arranged transmitter of the embodiment 1. Figure 14 is a vertical cross-section showing schematically a longitudinal view of the transmitter shown in Figure 13. Figure 15 is a plan view showing the transmitter shown in Figures 13 and 14. Figure 16 is a schematic cross-section showing a secondary cell of the EV battery of an embodiment 2. Figure 17 is a perspective view of a rectangular type cell shown in Figure 16. Figure 18 is a schematic cross-section view of a part of an electrode pair in the rectangular type cell shown in Figures 16 and 17. Figure 19 is a side view of an upper portion of an arranged EV battery of the embodiment 2. Figure 20 is a schematic cross-section of the case along a line A-A in Figure 19. Figure 21 is a schematic cross-section of three cells of the EV battery shown in Figure 19. Figure 22 is a schematic cross-section in the thickness direction, which shows a collector and an activity material layer in the cell shown in Figure 20 at a low temperature. Figure 23 is a schematic cross section in the thickness direction, which shows a collector and an activity material layer in the cell shown in Figure 20 at a high temperature. Figure 24 is a schematic cross section in the thickness direction, which shows a conventional flat collector and a flat activity material layer. Figure 25 is a schematic cross section in the thickness direction, which shows a conventional spirally-wound collector and a spirally-wound activity material layer.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(Embodiment 1)
A road-powered inductive EV-charging system of the embodiment 1 is explained referring to Figures 1-4. Figure 1 is a schematic side view of a vertical cross-section of a transmitter 550 and a receiver 650 in a longitudinal direction of the roadway. Figure 2 is a schematic plan view of the transmitter 550 and the receiver 650. Figure 3 is an enlarged vertical cross-section showing the transmitter 550 and the receiver 650 in a lateral direction of the roadway.

First, fundamental structure of transmitter 550 is explained. Transmitter 550 has a primary coil 506 wound around a primary core 511 made from soft ferrite with a high magnetic permeability and a low iron loss. The primary core 511 consists of a center core 7001, a front plate core 7002, a rear plate core 7003, a front wall core 7004 and a rear wall core 7005. Primary core 511 is buried in a concrete block 7006 fixed in a surface portion of a roadway 7000. The concrete block 7006 has a trench accommodating primary core 511 with primary coil 506. An upper surface of the concrete block 7006 is exposed from road surface GL of the roadway 7000.

The center core 7001, the front plate core 7002 and the rear plate core 7003 extend toward a longitudinal direction of roadway 7000 along a center portion of roadway 7000. A rear portion of front plate core 7002 comes into contact with a front portion of center core 7001 via the front wall core 7004. An upper surface of front wall core 7004 comes into contact with a lower surface of the rear portion of front plate core 7002. The front portion of center core 7001 is inserted into a hole of front wall core 7004. Similarly, a front portion of rear plate core 7003 comes into contact with a rear portion of center core 7001 via the rear wall core 7004. An upper surface of rear wall core 7005 comes into contact with a lower surface of the front portion of rear plate core 7003. The rear portion of center core 7001 is inserted into a hole of rear wall core 7005. Upper surfaces of plate-shaped front plate core 7002 and rear plate core 7003 are exposed from the road surface GL. The upper surfaces of the front plate core 7002 and rear plate core 7003 have equal height to road surface GL of roadway 7000.

The upper surfaces of the

plate cores

7002 and 7003 consist of rough surfaces with small convex portions and small concave portions. A friction coefficient of the upper surfaces of

plate cores

7002 and 7003 is nearly equal to a friction coefficient of the upper surface of roadway 7000. Namely, the friction coefficient of the upper surfaces of

plate cores

7002 and 7003 is 50-150% of the friction coefficient of the ground surface GL of roadway 7000. Accordingly, The EV does not slip on

plate cores

7002 and 7003, because

plate cores

7002 and 7003 made of soft ferrite tiles or soft ferrite bricks have rough surfaces. Concrete block 7006 has shallow trenches accommodating front plate core 7002 and rear plate core 7003. Further, concrete block 7006 has a deep trench accommodating primary coil 506 wound around center core 7001.

The deep trench of the concrete block 7006 accommodates a protection pipe 7007. An upper surface of the opening of the protection pipe 7007 is flat with the same height as road surface GL. Primary coil 506 wound around the column-shaped center core 7001 is accommodated in protection pipe 7007. Column-shaped center core 7001 of the primary core 511 has a circle-shaped cross-section vertically. A total length of primary coil 506 is shortened, because the center core 7001 has the circle-shaped cross-section. Protection pipe 7007 made from concrete is set on the bottom of the deep trench of the concrete block 7006. Accordingly, primary coil 506 and center core 7001 are surrounded by protection pipe 7007 and wall cores 7004 and 7005.

Next, fundamental structure of the receiver 650 is explained. Receiver 650 has a secondary coil 606 wound around a secondary core 611 made from soft ferrite with a high magnetic permeability and a low iron loss. The secondary core 611 consists of a front arm core 6111, a rear arm core 6112, a center core 6114, a front plate core 6116 and a rear plate core 6117. Secondary coil 606 is wound around the center core 6114 extending to a longitudinal direction of the EV stopping upon the transmitter 550. Center core 6114 is fixed to a bottom of the EV.

A rear portion 6111A of front arm core 6111 is supported rotatably to a rotating axis M1 fixed to the bottom of the EV. A front portion 6112A of rear arm core 6112 is supported rotatably to a rotating axis M2 fixed to the bottom of the EV. The

arm cores

6111 and 6112 are capable of swinging around the rotating axis M1 and M2 respectively. The rear portion 6111A of front arm core 6111 is adjacent to a front portion of center core 6114. The front portion 6112A of rear arm core 6112 is adjacent to a rear portion of center core 6114. Front plate core 6116 is supported to a top portion of front arm core 6111 rotatably in the vertical plane. The rear plate core 6117 is supported to a top portion of rear arm core 6112 rotatably in the vertical plane.

Arm cores

6111 and 6112 capable of swinging extend to the longitudinal direction of the EV, when

arm cores

6111 and 6112 are installed in the bottom of the EV as shown with broken lines in Figure 1.

The

plate cores

6116 and 6117 extend horizontally to a lateral direction, left/right direction of the EV. A central portion of front plate core 6116 has an upper portion 6116A projecting upward. The upper portion 6116A is supported rotatably around an axis M3 fixed to a top portion of front arm core 6111. A central portion of rear plate core 6117 has an upper portion 6117A projecting upward. The upper portion 6117A is supported rotatably around an axis M4 fixed to a top portion of rear arm core 6112.
A lower surface of front plate core 6116 comes into contact with the upper surface of front plate core 7002, when front arm core 6111 is swung downward. A lower surface of rear plate core 6117 comes into contact with the upper surface of rear plate core 7003, when rear arm core 6112 is swung downward.

Consequently, primary coil 506 and secondary coil 606 are connected inductively with primary core 511 and the secondary core 611, when

arm cores

6111 and 6112 are swung downward. As the result, primary coil 506 can supply an inductive power to secondary coil 606. After charging the EV battery,

arm cores

6111 and 6112 are swung upward by a hidden motor.

Arm cores

6111 and 6112 are protected well with an EV, when the EV is running.

Benefits of a pair of transmitter 550 and receiver 650 are explained. As shown in Figure 2, primary core 511 has a pair of

plate cores

7002 and 7003 extending to opposite sides of the longitudinal direction from center core 7001. A leakage inductance of primary coil 506 is reduced. Further, secondary core 611 has

plate cores

6116 and 6117 extending in parallel each other to the lateral direction. Accordingly, a large longitudinal position difference and lateral position difference between transmitter 550 and receiver 650 are permitted in the longitudinal direction and the lateral direction. For example, each of

plate cores

7002, 7003, 6116 and 6117 have a width of 4cm, a thickness of 1.5cm and a length of 30cm.

Center cores

7001 and 6114 have a diameter of 2.5cm and a length of 10cm. A primary current has a fundamental frequency of 40-60 kHz.

Next, the inductive power transmission is improved, because a magnetic circuit consisting of primary core 511 and secondary core 611 has a small magnetic resistance, when

plate cores

6116 and 6117 come into contact with

plate cores

7002 and 7003.
According to a preferred embodiment, the cores are covered with non magnetic member for reinforcing and cooling.

Another road-powered inductive EV-charging system is explained referring to Figures 4-6. Figure 4 is a schematic cross-section of transmitter 550 and receiver 650 in the longitudinal direction of the roadway. Figures 5 and 6 are vertical cross-sections showing transmitter 550 and receiver 650 shown in Figure 4 in the lateral direction of the roadway. Transmitter 550 and receiver 650 shown in Figures 4-6 are essentially same as transmitter 550 and receiver 650 shown in Figures 1-3. However, primary core 511 shown in Figure 4 has a front core 7009 instead of front wall core 7004 and center core 7001 shown in Figure 1. Further, primary core 511 shown in Figure 4 has a rear core 7008 instead of rear wall core 7005 and center core 7001 shown in Figure 1.

Furthermore, the system shown in Figures 4-6 has a circuit box 711 and cable conduits 712. A plurality of the circuit box 711 arranged to one line under the roadway is connected with the cable conduits 712. Each circuit box 711 made from concrete is fixed under the protection pipe 7007, rear core 7008 and front core 7008, which surrounds primary coil 506. Circuit box 711 accommodates an oscillator supplying the oscillating current to primary coil 506. Cables in the cable conduits 712 apply a DC voltage to the oscillator in the circuit box 711. According to this arranged embodiment, the oscillator is placed at adjacent position to primary coil 506. Therefore, a load inductance of the oscillator can be decreased, because a line inductance between the oscillator and the primary coil 506 is decreased. Furthermore, an electromagnetic noise radiated from the line is reduced.

Another arrangement of the transmitter is explained referring to Figures 7. Figure 7 is a schematic side cross-section of transmitter 550. Transmitter 550 shown in Figures 7 is essentially same as transmitter 550 shown in Figures 4. However, primary core 511 shown in Figure 7 has a front plate core 7020 instead of front plate core 7002 shown in Figure 4. Further, primary core 511 shown in Figure 7 has a rear plate core 7030 instead of rear plate core 7003 shown in Figure 4. The plate cores 7020 and 7030 are made from concrete or asphalt, in which soft magnetic powder is mixed. Plate cores 7020 and 7030 have larger thickness than

plate cores

7002 and 7003 made from soft ferrite. According to this arranged embodiment, plate cores 7020 and 7030 extending long to the longitudinal direction of the roadway have a low cost and good driving feeling.

Next, transmitters 550 arranged near an intersection 1001 of the roadway 1000 are explained referring to Figure 8. Figure 8 is a plan view near intersection 1001 of roadway 1000. The EVs 1004 are stopping just upper position of three transmitters 550 disposed on roadway 1000. A power box 720 with an AC/DC converter supplies a DC voltage to each of transmitters 550 via cables 712. The power box 720 accommodates a central controller controlling the DC power supply, too.

Traffic signal generators 1002 transmit a traffic signal to EVs 1004 via the power box 720, cables 712, and a transmitter 550 to the receiver of EVs 1004. EVs 1004 have a charging controller controlling the inductive charging. The charging controller of each EV judges a charging-off timing in accordance with the traffic signal received from the traffic signal generators 1002. The controller stops the inductive charging and swings arm

plates

6111 and 6112 upward, just before the traffic signal shows red to green. As the result, each EV 1004 can start to run without a delay time.

Next, another arrangement of transmitter 550 disposed on the roadway 7000 is explained referring to Figures 9-10. Figure 9 is a plan view showing transmitter 550 disposed near the traffic signal generator 7009. Figure 10 is a vertical cross-section showing an inductive guide line 7008 in the lateral direction of roadway 7000. An inductive guide line 7008 made of a steel line is buried in the surface portion of roadway 7008. The inductive guide line 7008 extends to the longitudinal direction of roadway 7000 along a laterally-center lane of roadway 7000. Accordingly, the EV can detect the laterally-center position, which is central in the lateral direction of roadway 7000 by using secondary core 611.

The position-detecting method using the steel line 7008 is explained referring to Figures 11-12. A pick-up coil 6060 is wound around center core 6114. Front arm core 6111 with front plate core 6116 extends forward from center core 6114 of secondary core 611. Rear arm core 6112 with rear plate core 6117 extends backward from center core 6114. A vehicle oscillator 6061 supplies an oscillating current Is with constant average amplitude to a pick-up coil 6060 wound around center core 6114 via a resistor element 6062. A voltage drop Vs of the resistor element 6062 is proportional to amplitude of the oscillating current Is. The voltage drop Vs is increased, when plate cores 6116 and 6118 are apart from the steel line 7008. As the result, a position controller 6063 can detects whether or not the steel line 7008 is positioned just under

plate cores

6116 and 6117. The position controller 6063 transmits an alarm signal, when

plate cores

6116 and 6117 are not upon steel line 7008.

Further, the voltage drop Vs decreases strongly, when secondary core 611 reaches a just upper position of primary core 511, because an inductance of the pick-up coil 6060 is increased largely. Therefore, position controller 6063 can detects the EV arrives at the stopping position. After all, pick-up coil 6060 wound around the secondary core 611 can detects the lateral position and the longitudinal position of the moving EV. A driver can stop the EV at a preferable position for inductive charging by using the output signal of the pick-up coil 6060. Furthermore, the EV can be automatically stopped in accordance with the output signal of the pick-up coil 6060 at the preferable position. A position-detecting operation shown in Figure 12 is executed with a predetermined short interval. At a step S200, position controller 6063 detects the voltage drop Vs. At a step S202, position controller 6063 detects the lateral position difference between the secondary core and the guide line.

Further, position controller 6063 detects the longitudinal position difference between the secondary core and the primary core. The primary coil 506 can supply a small alterative current for detecting the longitudinal position difference between the secondary core and the primary core. The position controller 6063 detects the preferable longitudinal position, when the induced voltage of the pick-up coil 6060 becomes larger than the predetermined value.

Next, another arrangement of transmitter 550 disposed on the roadway 7000 is explained referring to Figures 13-15. Figure 13 is a vertical cross-section of the transmitter 550 in the lateral direction of the roadway. Figure 14 is a vertical cross-section of the transmitter 550 in the longitudinal direction of the roadway. Figure 15 is a schematic plan view of the transmitter 550. Transmitter 550 shown in Figures 13-15 are essentially same as transmitter 550 shown in Figures 4. However, primary coil 506 shown in Figure 13-15 is covered with a pair of half-cylinder-shaped

cooling members

7021 and 7022. The half-cylinder-shaped cooling members 7021 made from electric insulation material covers an upper half of a circumferential surface of primary coil 506. The half-cylinder-shaped cooling members 7022 made from aluminum covers a lower half of a circumferential surface of primary coil 506. An electric insulation resin film is laminated on a surface of the half-cylinder-shaped cooling members 7022. Each half-cylinder-shaped

cooling member

7021 and 7022 has excellent heat conductivity. The half-cylinder-shaped cooling members 7022 can extend outside of the concrete block 7006. Each half-cylinder-shaped

cooling member

7021 and 7022 is accommodated between an inner surface of the concrete block 7006 and an outer circumferential surface of primary coil 506. Accordingly, cooling

members

7021 and 7022 can radiate primary coil 506 strongly. A trench 7110 of circuit box 711 accommodates the oscillator 7120 supplying the oscillating current to primary coil 506.
(Embodiment 2)

The embodiment 2 is explained referring to Figures 16-19. Figure 16 is a schematic cross-section of a rectangular type EV battery. Figure 17 is a perspective view of a rectangular type cell shown in Figure 16. Figure 18 is a schematic section view of a part of an electrode pair in the rectangular type cell shown in Figures 16 and 17. A battery 100 has ten cells 102 installed in a rectangular-box-shaped battery case 101. Each cell 102 is a Lithium ion cell arranged in turn to the thickness direction of the cell 102.

The cell 102 has a bended cell case 103 and an electrode assembly accommodated in the case 103. The bended cell case 103 has a pair of

major sidewalls

103A and 103B, which are in parallel each other. The

major sidewalls

103A and 103B are adjacent each other across the electrode assembly in cell case 103. As shown in Figure 29, major sidewalls 103A of cells 102 have a convex surface in the width direction and the thickness direction each. In the other words, each major sidewall 103A consists of a convex portion each.

Major sidewalls 103B of cells 102 have a concave-surface in the width direction and the thickness direction each. In the other words, each major sidewall 103B consists of a concave portion each. The thickness of cell 102 between two

major sidewalls

103A and 103B is almost constant. The electrode assembly constituting laminated electrode pairs is curved along adjacent two

major sidewalls

103A and 103B. A major surface of the laminated electrode pairs being adjacent to major sidewall 103A has convex-shape. A major surface of the laminated electrode pairs being adjacent to major sidewall 103B has concave-shape. Accordingly, the major surface of the laminated electrode pairs has a convex portion. The major surface of the laminated electrode pairs has a concave portion.

A radius of major sidewall 103A is larger than a radius of major sidewall 103B as shown in Figure 16. Accordingly, a gap 'G' is formed between adjacent

major sidewalls

103A and 103B.

Major sidewalls

103A and 103B of cell case 103 extends straightly to the length direction 'L' as shown in Figure 17. Accordingly, the gap 'G' extends straightly and penetrates among cells 102 to the length direction 'L' of cell case 103. Each cell 103 is radiated by cooling fluid flowing through each gap 'G'. Instead of the cooling fluid, heat pipes can be inserted into the gaps 'G'.

As shown in Figure 16, an inner side surface of rectangular battery case 101 has a convex portion attached fully to the concave portion of major sidewall 103B. Another inner side surface of rectangular battery case 101 has a concave portion attached fully to the convex portion of major sidewall 103A, too. The electrode pair has a sheet-shaped anode and a sheet-shaped cathode, which are adjacent, each other across a sheet-shaped separator.

Figure 18 shows one electrode pair 104 being a part of the electrode assembly. The electrode pair 104 consists of a sheet-shaped anode 104A and a sheet-shaped cathode 104B, which are adjacent each other across the sheet-shaped separator 104C. Anode 104A has a sheet-shaped anode activity material layer 104AA adhered to a sheet-shaped metal collector 104AB. Cathode 104B has a sheet-shaped cathode activity material layer 104BB adhered to a sheet-shaped metal collector 104BA. The collector, the activity material layer and the separator 104C are curved. Accordingly, one major side surface 105 of electrode pair 104 has convex-shape. Another major side surface 106 of electrode pair 104 has concave-shape.

Cell case 103 is a closed vessel made of stainless steel plates connecting each other by means of welding. The cell case 103 is stronger than a conventional plane type cell case with an equal thickness. The cell case 103 is cooled better than a conventional cylindrical type cell. Furthermore, it is not easy to detach the bended activity material layer from the collector in comparison with prior cells with the plane type and the cylindrical type.

Bending process of electrode assembly is explained. The activity material paste with a constant thickness can be adhered on the curved collector. An electrode pair can be bent before or after the drying step of the electrode pair. The electrode assembly consisting of the laminated electrode pairs can be bent before inserting the electrode assembly into the curved cell case.

Figure 19 shows a side view of an upper portion of a cell 1. The cell 1 has a case 2 installing electrode assembly (not shown). An anode terminal 3 and a cathode terminal 4 are projecting from an upper end plate of the case 2. Case 2 has a stainless steel can and an upper end plate for enclosing an opening of the can. The anode terminal 3 and the cathode terminal 4 are fixed to the upper end plate made of a resin plate. The electrode assembly is formed with laminating a plurality of electrode pairs. Each electrode pair consists of a sheet-shaped anode and a sheet-shaped cathode, which are sandwiched across the sheet-shaped separator. The sheet-shaped anode has the collector, on which the anode activity material layer is adhered. The sheet-shaped cathode has the collector, on which the cathode activity material layer is adhered. The collector consists of the sheet made of an aluminum sheet or a copper sheet.

Another arrangement of the embodiment 2 is explained referring to Figures 20-21. Figure 20 shows a cross-section of the case 2 along the line A-A in Figure 19. The case 2 has the corrugate shape extending to the width direction 'W' of cell case 2. The electrode assembly (not illustrated) is installed in case 2. The electrode assembly has two major side surfaces, which are adjacent to two

major sidewalls

21 and 22 of the case 2. Each of the

sidewalls

21 and 22 of case 2 has corrugate shape. A pair of

major walls

21 and 22 of case 2 has linear convex 23 and linear concave 24 each. Linear convex 23 and linear concave 24 are alternately arranged to the width direction W with a predetermined pitch. Linear convex 23 of major sidewall 21 and linear concave 24 of major sidewall 22 are adjacent each other across the electrode assembly in the thickness direction 'T'.

Similarly, linear concave 24 of major sidewall 21 and linear convex 23 of major sidewall 22 are adjacent each other across the electrode assembly in the thickness direction 'T'. Each convex 23 and each concave 24 extend straightly in parallel to the length (height) direction of case 2. Accordingly,

major sidewalls

21 and 22 of case 2 have a plurality pairs of convex 23 and concave 24 arranged in turn. Preferably, a number of convex 23 of major sidewall 21 are equal to a number of convex 23 of major sidewall 22. A number of concave 24 of major sidewall 21 are equal to a number of concave 24 of major sidewall 22. Major sidewall 21 has equal shape to major sidewall 22 after all. A radius of convex 23 is bigger than a radius of concave 24. The electrode assembly has corrugate-shape, which is almost equal to corrugate-shape of case 2. After all, the anode and the cathode of each electrode pair have the corrugate shape.

Figure 21 shows three cells 11-13 constituting a part of the battery. Three secondary cells 11-13 are adjacent each other in the thickness direction in turn. Each concave 24 of the first secondary cell 11 is adjacent to each convex 23 of the second cell 12. Gap G is formed between concave 24 of the first cell 11 and the convex 23 of the second cell 12. Convex 23 of the first cell 11 is adjacent to the concave 24 of the second cell 12. Gap 'G' is formed between the convex 23 of the first cell 11 and the concave 24 of the second cell 12. Concave 24 of the second cell 12 is adjacent to convex 23 of the third cell 13. In other words, concave 24 of one cell is adjacent to convex 23 of the adjacent another cell.

Each convex 23 and each concave 24 extend straightly to the length direction 'L'. The linear gap 'G' extending to the length (height) direction is formed between the linear convex 23 and the linear concave 24. The cross section of gap 'G' has crescent-moon-shape as shown in Figure 32. Each linear gap G extending to the length direction 'W' of case 2 constitutes each cooling fluid passage in which the cooling fluid flows. Each cell is cooled with the cooling fluid. The cell 1 with corrugate shape has a superior cycle life in comparison with the conventional cylinder-shaped cell and the conventional plate-shaped cell.

The reason is explained. The difference on the thermal expansion rate between the collector and the activity material layer destroys contact between the collector and the activity material layer. The corrugate-shape of the collector and the activity material layer restrains the movement of them. Figure 22 schematically shows an activity material layer 7 and a collector 6. The collector 6 shown schematically has a triangle-shape. The activity material layer 7 adheres to both side of collector 6. The sheet-shaped activity material layer 7 has approximately constant thickness. The collector 6 made of a metal sheet has bigger linear expansion rate than the activity material layer 7 made from inorganic material mainly. Collector 6 can be considered to be aggregate of a large number of small plate portions 60 extending diagonally. When cell 1 is heated rapidly, odd small plate portions 60 extend to a diagonal lower direction. Even small plate portions 60 extend to a diagonal upper direction. As a result, when cell 1 rises rapidly, each small plate portion 60 is going to slide along a flat surface of activity material layer 7.

A state after the slide is shown in Figure 23. Two small plate portions 60 adjacent each other has different expansion direction each other. Therefore, the mechanical stress between collector 6 and activity material layer 7 grows the biggest at a combination region of each small plate portion 60. In particular, at the position adjacent to convex 23, the strong stress occurs at activity material layer 7. This mechanical stress is in proportion to the length of small plate portion 60 to the width direction S of the small plate portion 60. By the slide of collector 6 has the corrugate shape, the activity material layer 7 adjacent to convex 23 of the collector 6 removes after all. The mechanical stress in the activity material layer is distributed at many portions of the activity material layer 7, because collector 6 has a plurality of convex 23. The above dispersion of the mechanical stress means that each mechanical stress of every portion of collector 6 decreases. Furthermore, partial concentration of the mechanical stress in activity material layer 7 is evaded, because collector 6 curves continually.

Figure 24 shows a reference example with the conventional flat collector 6A and the conventional flat activity material layer 7A adhering each other. In Figure 24, both ends of collector 6A lengthen outside to the width direction from both ends of activity material layer 7A, when the temperature of the cell rises. When the temperature of cell 1 rises, quantity of extension 'L' of collector 6A becomes a product of the linear expansion rate k of collector 6A and the width Wa of collector 6A. As the linear expansion rate of activity material layer 7A adhering to collector 6A is small, collector 6A is going to slide along a contact surface of activity material layer 7A. The slide of collector 6A for activity material layer 7A occurs from a center point X of collector 6 to both sides in the width direction. As the result, both ends of collector 6A exfoliate from activity material layer 7A, because the width Wa of the flat collector 6A is big.

Figure 25 shows another reference example with a spiral-cylinder-shaped collector 6B and a spiral-cylinder-shaped activity material layer 7B adhering each other. As a linear expansion rate of activity material layer 7B adhering to collector 6B is small, the collector 6B is going to slide along a contact surface of activity material layer 7B, when the cell is heated rapidly. When the temperature of collector 6B rises, an outer end of collector 6B lengthens to the circumferential direction. This extension is performed from an inner end of an internal circumference side of collector 6B. The end of an outer periphery of collector 6B exfoliates from the end of the outer periphery of the activity material layer 7B. However, the curved cylindrical collector 6B reduces the detachment of the activity layer.

In contrast, collector 6 and activity material layer 7 of the present embodiment has corrugate shape to the width direction. Collector 6 has each small plate portion 60 extending diagonally between each flexural point. Small plate portions 60 have different extending directions alternately. Increased length of each small plate portion 60 is small, because the length of each small plate portion 60 is short. The largest value of the tension of each small plate portion 60 is reduced. As a result, increasing of the electrical resistance between activity material layer 7 and collector 6 can be restrained. The corrugate case 2 can consist of two corrugate metal plates insulated each other. These corrugating metal plates can be used as the anode terminal and the cathode terminal.

Claims

A road-powered charging system for an electric vehicle comprising a transmitter (550) and a receiver (650):
the transmitter (550) has a primary coil (506) wound on a primary core (511) made from soft magnetic material; and
the receiver (650) disposed to the electric vehicle has a secondary coil (606) wound on a secondary core (611) made from soft magnetic material;
wherein the transmitter (550) disposed in a roadway (7000) including a parking zone;
the secondary core (611) has a center core (6114) and a pair of moving cores (6111, 6112, 6116 and 6117);
the secondary coil (606) is wound around the center core (6114) fixed to a bottom of the electric vehicle; and
the primary coil (506) and the secondary coil (606) are coupled inductively in a battery-charging period while the moving cores (6111, 6112, 6116 and 6117) move downward from a bottom of the electric vehicle.
The road-powered inductive charging system for the electric vehicle according to claim 1;
wherein the moving cores (6111,6112, 6116 and 6117) has a front moving core (6111, 6116) and a rear moving core (6112, 6117);
the center core (6114) extends to a longitudinal direction of the electric vehicle;
the front moving core (6111) is adjacent to a front portion of the center core (6114); and
the rear moving core (6112) is adjacent to a rear portion of the center core (6114);
The road-powered inductive charging system for the electric vehicle according to claim 2;
wherein the front moving core (6111) has a front arm core (6111) capable of swinging around one rotating point (M1) being adjacent to the front portion of the center core (6114); and
the rear moving core (6112) has a rear arm core (6112) capable of swinging around another rotating point (M2) being adjacent to the rear portion of the center core (6114);
The road-powered inductive charging system for the electric vehicle according to claim 2;
wherein the front moving core has a front plate core (6116) supported rotatably to a top portion of the front arm core (6111);
the rear moving core (6112) has a rear plate core (6117) supported rotatably to a top portion of the rear arm core (6112); and
the plate cores (6116, 6117) extend horizontally to a lateral direction of the electric vehicle.
The road-powered inductive charging system for the electric vehicle according to claim 4;
wherein the arm cores (6111, 6112) are swung in the vertical direction including the longitudinal direction;
the arm cores (6111, 6112) extend to the longitudinal direction along a bottom of the running electric vehicle; and
the plate cores (6116, 6117) extend horizontally to the lateral direction of the electric vehicle.
The road-powered inductive charging system for the electric vehicle according to claim 1;
wherein the primary core (511) has a center core (7001), a front plate core (7002) and a rear plate core (7003);
the primary coil (506) is wound around the center core (7001) of the primary core (511);
the front plate core (7002) extends forward from a front portion of the center core (7001) of the primary core (511) along a upper surface of the roadway; and
the rear plate core (7003) extends backward from a rear portion of the center core (7001) of the primary core (511) along an upper surface of the roadway.
The road-powered inductive charging system for the electric vehicle according to claim 6;
wherein the center core (7001), the front plate core (7002) and the rear plate core (7003) of the primary core (511) extend to one line to the longitudinal direction of the roadway.
The road-powered inductive charging system for the electric vehicle according to claim 6;
wherein the primary core (511) has a front wall core (7004) and a rear wall core (7005), which is extending vertically;
the front wall core (7004) connects magnetically between the front portion of the center core (7001) and a rear portion of the front plate core (7002);
the rear wall core (7005) connects magnetically between the rear portion of the center core (7001) and a front portion of the rear plate core (7003); and
the center core (7001) of the primary core (511) is buried at deeper position than the front plate core (7002) and the rear plate core (7003);
The road-powered inductive charging system for the electric vehicle according to claim 6;
wherein the center core (7001) is made of a column-shaped core,
The road-powered inductive charging system for the electric vehicle according to claim 6;
wherein the front plate core (7002) and the rear plate core (7003) of the primary core (511) have a pair of road core portions made (7020, 7030) from soft magnetic powder mixed in road material; and
the center core (7001) of the primary core (511) has larger magnetic permeability than the road core portions (7020, 7030) extending to the longitudinal direction.
The road-powered inductive charging system for the electric vehicle according to claim 6;
wherein the front plate core (7002) and the rear plate core (7003) of the primary core (511) have an upper surface exposed on the ground surface of the roadway; and
the upper surface of the plate cores (7002, 7003) has nearly equal average value of a friction coefficient to the ground surface of the road way.
The road-powered inductive charging system for the electric vehicle according to claim 6;
wherein the front plate core (7002) and the rear plate core (7003) of the primary core (511) is separated from the center core (7001) of the primary core;
The road-powered inductive charging system for the electric vehicle according to claim 1;
wherein the moving cores (6111, 6112, 6116 and 6117) are moved upward in accordance with a received traffic signal, when the stopping electric vehicle is charged from the transmitter (550) disposed near an intersection of the roadway.
The road-powered inductive charging system for the electric vehicle according to claim 1;
wherein the primary core (511) is on a circuit box (711) accommodating an oscillator supplying an primary current to the primary coil (506); and
the circuit box (711) is connected to a cable conduit (712) extending to the longitudinal direction.
The road-powered inductive charging system for the electric vehicle according to claim 1;
wherein the electric vehicle has a sensor detecting information related a distance between the sensor and the transmitter.
The road-powered inductive charging system for the electric vehicle according to claim 15;
the sensor has a pick-up coil (6060), a detecting circuit (6062, 6063) and an oscillating circuit (6061);
the pick-up coil (6060) is wound around the center core (6114) of the secondary core (611);
the detecting circuit (6062, 6063) detects the information related to the distance between the sensor (6114) and the transmitter (550) in accordance with an impedance of the pick-up coil (6060); and
the oscillating circuit (6061) supplies an alternative current with a predetermined high frequency to the pick-up coil (6060).
The road-powered inductive charging system for the electric vehicle according to claim 1;
wherein the battery (100) has cells (102) arranged in a thickness direction;
the cell (102) has two major side walls (103A, 103B) across an electrode assembly accommodated in a cell case (103) of the cell (102);
one of said two major side walls (103A, 103B) has at least one of a convex surface; and
the other one of the two major side walls (103A, 103B) has at least one concave surface.
The road-powered inductive charging system for the electric vehicle according to claim 17;
wherein the convex surface of the major side wall (103A) of one cell (102) is adjacent to the concave surface of the major side wall (103B) of another cell (102); and
a small gap (G) between adjacent convex surface and concave surface makes a passage flowing cooling fluid.
The road-powered inductive charging system for the electric vehicle according to claim 17;
wherein the concave surface and the convex surface of the cells (102) are curved in the width direction and the thickness direction of the cell (102); and
the concave surface and the convex surface extend straightly to the length direction of the cell (102).
The road-powered inductive charging system for the electric vehicle according to claim 17;
wherein the electrode assembly has a sheet-shaped electrode pair having a sheet-shaped anode (104A) and a sheet-shaped cathode (104B) across a sheet-shaped separator (104C);
the sheet-shaped anode (104A) and the sheet-shaped cathode (104B) consist of a sheet-shaped collector (104AB, 104BA) and both of activity material layers (104AA, 104BB) adhered on both major surfaces of the collector (104AB, 104BA); and
the major surfaces of the collector (104AB, 104BA) and the activity material layers (104AA, 104BB) are curved together along the bended major side walls (103A, 103B).
The road-powered inductive charging system for the electric vehicle according to claim 20;
wherein the major surfaces of the collector and the activity material layers have a corrugate shape; and
the two major sidewalls of the cell case have a corrugate-shaped cross-section each.