WO2010114455A1

WO2010114455A1 - Power outlet

Info

Publication number: WO2010114455A1
Application number: PCT/SE2010/000085
Authority: WO
Inventors: Lars Hjort
Original assignee: Hm Power Ab
Priority date: 2009-04-02
Filing date: 2010-03-31
Publication date: 2010-10-07
Also published as: SE0900441A1; SE535382C2

Abstract

A power supply system for charging of batteries for a plurality of electrically powered vehicles parked on a parking surface (13) comprises a plurality of power outlets (12) connected by cables (11) to a low-voltage switchgear (8). Each power outlet (12) comprises a post (35) and a connection module (36) supported by the post. The connection module comprises at least one lockable room comprising at least one power outlet (42). The room is arranged to accommodate a plug contact connected to the outlet. The room is restricted by a lockable cover (38). The cover encloses the plug contact in its locked position and forms a slot (46) for receiving a cord connected to the outlet. The power supply is activated only when the cover is locked.

Description

Power outlet

TECHNICAL FIELD The present invention relates to a system for power supply to temporarily parked electrically powered vehicles. Especially, the invention relates to a system for charging of batteries for an electrically powered vehicle. An electrically powered vehicle means every kind of vehicle that at any stage is powered by an electric motor and that includes a chargeable energy source. The most common energy source is a battery bank. Thus, it can be an electric car such as a city carOr a golf cart, or a hybrid car which also comprises a combustion engine for driving the car or charging of the battery bank. Such a system comprising a plurality of power outlets by which a plurality of temporarily connected electric cars are supplied by large amounts of energy at the same time. In particular the invention relates to a system for charging of the battery bank for a plurality of connected electric cars comprising a municipal or privately arranged parking place adjacent to a workplace, a residential area, a train station, an electric car rental or a parking garage.

BACKGROUND AND PRIOR ART

An electric car with battery bank can easily be charged via a standard wall outlet. This requires, however, that the electric car is connected to the power outlet for a long time because usually no more than 10 amps can be obtained from such an outlet. When connecting several such cars to the same outlet, it becomes problematic, since a standard wall outlet can not deliver such amounts of energy.

At a parking lot with a number of power outlets for charging of batteries for electrically powered vehicles, it requires a significantly greater possibility to satisfy the need to supply sufficient amounts of energy. The closest connection point to the power grid is often at a distance from the parking place and long low-voltage cables impose large losses. From US 2007/0126395 (Sucha) an automatic charging and docking station for electric cars is previously known. The known station is intended to be placed on public or private locations and includes a vehicle-mounted probe that is brought into contact with the station, whereby charging takes place. The probe contains an identity carrier which allows the owner to be billed retroactively.

From US 5548200 (Nor et al) a universal charging station for charging of batteries for electric cars is previously known. The aim of the charging station is to allow transmission of electrical energy to a battery as quickly as possible. The problem that the charging station seeks to overcome is that drivers should not have to wait several hours or overnight to get their car charged. The known station includes a rectifier which provides a number of charging outlets with direct current. Here, the vehicle and station are arranged to communicate with each other to control the charging stage.

From US 6081205 (Williams) an electronic charging station with parking meters for electric cars is previously known. The aim of the station is to offer a publicly accessible facility for charging of electric cars. The shown station comprises a number of parking meters, each provided with a power outlet and a central control unit. The central unit and the meters are mounted in a conventional manner at a curb or a parking lot. The wiring is made below the ground. In one embodiment each of the meters comprises a display and an electrical outlet, whereas the central unit includes a keypad, a card reader and a coin slot.

A parking meter according to the known charging station shows a lockable door which in its closed position covers the outlet, thereby preventing the insertion of a plug contact. At the initiation of a payment system, a pair of locking latches are affected so that the cover is opened. In this regard, it is thus possible for a customer to connect his contact and initiate the charging. Given that the system is intended to be placed in a public place, this solution is less successful from a safety point of view. As soon as the cover is open, it is available to everyone. The risk that a child can get current through the body is then imminent. The possibility of replacing the plug contact to steal current is also evident.

SUMMARY OF THE INVENTION The object of the invention is to indicate ways to bring about a system for power supply to a plurality of temporarily parked electrically powered cars that offers a secure handling for the consumers.

This object is achieved according to the invention by a power supply system according to the features as defined in the characterising part of the independent claim 1, and by a method according to the features as defined in the characterising part of the independent method claim 9. Advantageous embodiments are defined in the characterising parts of the dependent claims.

According to the invention, the power supply system comprises a plurality of power outlets connected by cables on the ground to a low- voltage switchgear and a cable protection device which protects the cabling. The power outlets comprise a supporting post and a connection unit placed thereon. The supporting post is anchored without digging and is designed so that the cabling up to the connection unit is protected. The post also includes an adjustment device by which the post can be adjusted to assume a vertical position. The cable protection devices are secured to a parking surface with a plurality of joints. Suitable joints may be nail or screw joints or glue joints.

Because the cable protection devices are placed on the ground, digging is avoided. The system thus becomes less costly. The system also becomes more flexible because the cable protection device is made up of modules which with the right tools can be easily moved. The cable protection device forms in one embodiment a base to the posts which thus do not involve digging either. In one embodiment the supporting post is anchored in the ground whereby the cabling is protected by a lining enclosing the post. Also at this anchoring, digging is avoided in that the post is pressed down into the ground. In one embodiment a plurality of outlets are arranged on each connection unit. Preferably, the power outlets are common one-phase outlets for 230 V. In other countries, other voltage levels may be applied. The invention also includes three-phase power outlets.

In one embodiment of the invention the connection unit comprises a cover in front of each outlet. The cover covers a small room in front of the outlet that is large enough to accommodate a plug contact. The cover also comprises a slot that allows a cable to pass out. The movement of the cover is coordinated with a control system so that power is available only when the cover is closed. When the cover is locked, the plug contact is inaccessible to both children and drivers. Hereby, the security that must be provided at a facility in a public place is achieved, while at the same time unauthorized access to the outlets is prevented. An LED is arranged to show if voltage is present.

The power supply system also comprises a control and payment system. In a control unit there is arranged a device for payment with some form of identity carriers. It can be a credit card or other cards, or a so-called RFID card. The control unit may include a separate control module or be housed in the switchgear or in the connection unit. Alternatively, the power supply system is set up with a function that identifies the car or driver to retroactively be able to send an invoice. In one embodiment the fee is paid by an SMS message or other means of payment via a phone subscription, or other equivalent means of payment. The control unit can be located in the respective post, but can also be centrally located and cover the need for a plurality of posts.

The lockable cover interacts with the payment system. The locking device is arranged to be open for connection by a plug contact when the power outlet is without current. When the payment procedure has started the cover is locked over the plug contact. The cover is opened again upon completion of the payment procedure. During the charging the plug contact can not be moved, which prevents anyone from replacing the plug contact to illegally access current. A control module that can be housed in a switchgear regulates the energy supply and also contains functions for payment or invoicing.

According to a first aspect of the invention, the object is achieved by a power supply system for charging of batteries for a plurality of electrically powered vehicles parked on a parking surface, comprising a plurality of power outlets connected by cables to a low-voltage switchgear, wherein each power outlet comprises a post and a connection module supported by the post, wherein the connection module comprises at least on lockable room comprising at least one power outlet, the room is arranged to accommodate a plug contact connected to the outlet, the room is restricted by a lockable cover, the cover encloses the plug contact in a locked position and forms a slot for receiving a cord connected to the outlet, and wherein the power supply is activated only when the cover is locked. In one embodiment the cables are drawn directly on the ground and covered with a cable protection device arranged to resist damage and collision. In one embodiment the cable protection device comprises modules which are secured to the ground surface by fastening devices. In one embodiment a module constitutes a base to the power outlet. In one embodiment an inner post which is pressed down in the ground constitutes a base to the power outlet. In one embodiment the power supply system comprises a control module for measurement, control and payment of the power D

supply service. In one embodiment this control module is housed in the connection module. In one embodiment an electricity meter is housed in the connection module in the event that the car owner rents a parking surface for a long time. The electricity meter can be remotely read and the driver is billed for the power consumption, for example once a month.

According to a second aspect of the invention, the object is achieved by a method for charging of batteries for an electrically powered vehicle, with a power supply system comprising a plurality of power outlets connected by cables to a low-voltage switchgear, wherein each power outlet comprises a post and a connection module supported by the post, wherein a lockable room comprising at least one power outlet is arranged in the connection module, the room is arranged to accommodate a plug contact connected to the outlet, the room is restricted by a lockable cover, a slot is formed with the cover in locked position for receiving a cord connected to the outlet, and wherein the power supply is activated only when the cover is locked. In one embodiment a consumer connects his electric car to the power outlet, identifies himself at a control unit so that power is supplied and the connection is locked, and after completed charging identifies himself again whereby the connection is opened and an invoice is sent.

DESCRIPTION OF THE DRAWINGS

The invention will now be explained in more detail by description of embodiments with reference to the enclosed drawings, wherein

fig 1 is a power supply system for charging of batteries for temporarily parked electrically powered vehicles,

fig 2 is an embodiment of a connection module, and fig 3 is a schematically shown installation for power supply to a plurality of electrically powered vehicles according to the invention in which the power supply system is included.

DESCRIPTION OF EMBODIMENTS

An embodiment of a power supply system with a plurality of power outlets for connection to a plurality of electric cars is shown in figure 1. The power system comprises a plurality of power outlets 12, each of which includes a connection module 36 supported by a post 35 and a cable protection device 30 which protects the cables pulled on the ground. The cable protection device 30 is, in the shown example, designed as a crescent-shaped casing of a resistant material. The protection device shall resist, i.a., damage and collision. The cable protection device may consist of several modules 41 which are built together by joints 31 and secured to the ground by outer fastening devices 32. In one embodiment the cable protection device is secured by an inner fastening device 33. The fastening devices can be secured to the ground by screw or nail joints or by glue or equivalent adhesive. Because the cables are placed on the ground and are protected by the cable protection device, digging is avoided, which results in a cost saving.

The cable protection modules 41 form, in the shown example, a base for a plurality of posts, each one supporting its connection module 36. Each connection module has at least one outlet. In one embodiment the power outlet includes an inner post 45 that is driven down and anchored in the parking surface. In this embodiment the outer post 35 becomes a lining that encloses the inner post and protects the cables pulled between the inner and outer posts. Thus, it is possible to first place all posts, then to pull all the cables and finally to cover all cables with a cable protection device and lining. In one embodiment the connection module includes at least four outlets. Each post is provided with an adjusting device 37 by which the post is adjustable to a vertical position.

In one embodiment the connection module has two outlets, each one covered by a lockable cover 38. The shown example also comprises a payment and control module 39 by which a customer can pay or be identified through, for example, a credit card or a so-called RFID card or other similar identity carrier. The payment may also be effected via the Internet, through payment by mobile phone subscriptions or through interactive card systems. In one embodiment the low-voltage switchgear 8 and the control module 39 are housed in the same casing. The module also includes means for wireless communication by which the power outlets can be controlled or information be obtained from, for example, a mobile phone. In the shown example a power outlet includes a reader 40 for a credit card or the like, whereby the payment and control module can be excluded.

The power outlets 12 are designed with one or several outlet fittings and a device for controlling the charging current as well as any supplementary heating in the car. In one embodiment the power outlet is dead (without voltage) as long as no plug contact is seated in the outlet. This is to prevent fingers from coming into contact with live parts of the outlet and to prevent uncontrolled power output. When the plug contact is plugged into the outlet, the cover is closed and the voltage supply is activated by the car driver, voltage is connected while at the same time a locking device prevents removal of the plug contact or access to the power outlets. The system is designed so that the locking devices are released in case of a general power failure.

The car driver activates the charging by using a key lock, a credit card, an SMS code, a code lock or some other device. This can be effected by a mobile phone or at an activation machine 39. Simultaneously with the activation, measurement is initiated as a basis for invoicing of the common parking and charging service. The measurement, which may consist of time measurement, energy measurement or both, ends in the connection being deactivated by the car driver. Invoicing is done by billing via the phone bill or similarly, or by charging on a credit card. The heating outlet can be activated by means of an SMS and a mobile phone, a clock, or in a similar manner.

In one embodiment the power supply system is arranged on an existing parking place. The cable protection devices are laid out on the existing ground surface and the posts with the outlet units are secured to the cable protection devices. Since the ground surface may sometimes be slightly inclined, the posts are adjusted to a vertical position. Cables 11 are pulled from the transformer via the low-voltage switchgear to the respective power outlet 12. To avoid having to bury the cables in the ground, the cables are laid directly on the ground surface and are protected by the cable protection device 30. The fastening devices 32 are adapted for asphalt or other ground coverings.

In one embodiment of the invention the connection module is supported by an inner post 45 that is pressed down into the ground. With the right tools the post is pressed down into the ground without having to perform digging. This pressed-down inner post forms a base for the outer post 35 which by an adjustment device 37 is secured to the inner post. The cabling to the connection module is pulled between the inner post and the outer post.

A connection module 36 according to one embodiment of the invention is shown in figure 2. Its top side is slightly larger than the bottom side to offer good protection from rain. The module has two outlet units, each covered with a cover 38, one of which is shown in an open position. The cover protects an inner room 51 with space for at least one electric outlet 42. In the embodiment shown the outlet comprises two phases but it may very well also be a three-phase outlet. The cover is pivotely mounted on two hinges 47 and has at its opposite side, two striker plates 44 for receiving a respective locking bolt in the connection module. According to one embodiment the locking bolts are resilient. When the cover closes, these are first moved backwards so as then to enter into the striker plates and lock the cover. The locking bolts are then arranged to be retracted by an electromotive force so that the cover is opened.

The connection module further includes an LED 50 which indicates if voltage is present. A reader 40 for sensing an identity carrier or an interactive acting card is arranged on the front side of the module. A solar cell 48 for backup operation is arranged on the top side and one or more lighted windows 49 for information or advertising is/are arranged on the sides of the module. The room inside the cover is arranged to accommodate a plug contact (not shown) that is connected to the outlet 42. When the cover is closed, a slot 46 is arranged to allow passage for a cord attached to the plug contact. The slot is designed so that fingers can not penetrate and reach the outlet, and can be provided with a lip of an elastic material that protects the room from the weather.

The installation according to figure 3 is intended for an infrastructure such as power supply, measurement, control and payment system for charging of electric and electric hybrid cars when they are parked in a parking lot.

Charging time and power are crucial for the amount of energy a system can deliver. Since the power output from the respective car becomes quite large and the charging time should be less than 5 - 6 hours, there is usually no possibility to pull power supply by a low-voltage cable from the nearest network station. On the one hand, there is usually no capacity, and on the other, the low-voltage cables become long, and thus both expensive and suffer from large losses. According to the invention the installation is configured such that the electrical pressure point, the transformer, is directly connected to the parking lot.

Power supply is obtained via connection of a high-voltage switchgear 1 with a T-branching arranged at a suitable place in an existing cable-fed network station loop. Usually such a connection is at 10 or 24 kV. The connection point is chosen so that a minimal distance is obtained, but also so that a suitable room is obtained where the switchgear can be installed in co-operation with the surrounding environment. The switchgear includes a circuit breaker 3 for opening and closing and a device 4 for tripping of the circuit breaker upon an electrical fault. Special design of the T-branching makes its outer dimensions limited and thus allows it to be erected without a building permit.

The high-voltage switchgear 1 is thus located adjacent to the distribution grid 2 and is directly connected to the transformer 7 by a high-voltage cable 5. By directly connected is to be understood that the high-voltage switchgear is directly connected to the transformer without the need of additional circuit breakers. The high-voltage switchgear 1 includes a circuit breaker 3 which is controlled and powered via a signal cable 16 from the low-voltage switchgear 8 of the transformer.

From a high-voltage switchgear 1, a radially feeding cable 5, which is intended for 10-36 kV, extends to a transformer caisson 6, which is advantageously placed below the ground and thereby does not steal existing ground surface, and also does not change or interfere with the environment aesthetically. A distribution transformer 7 is placed in the caisson, normally with ratings of 10-36/0.4 kV. The low-voltage side of the transformer feeds a low-voltage switchgear 8 having a plurality of switches 9 arranged in a casing 21. The casing can be designed in the same way as the cable cabinets that normally exist today. A ventilation device 10 is connected to the caisson which includes one or more fans 1

for ventilation of the heat losses from the transformer in the transformer caisson.

From the low-voltage switchgear, low-voltage cables 11 extend which supply various rows of outlets 12 placed on posts at a parking surface 13 comprising a number of parking boxes.

Claims

1. A power supply system for charging of batteries for a plurality of electrically powered vehicles parked on a parking surface (13) comprising a plurality of power outlets (12) connected by cables

(11) to a low-voltage switchgear (8), wherein each power outlet

(12) comprises a post (35) and a connection module (36) supported by the post, c h a r a c t e r i s e d i n that the connection module comprises at least one lockable room comprising at least one power outlet (42), that the room is arranged to accommodate a plug contact connected to the outlet, that the room is restricted by a lockable cover (38), that the cover encloses the plug contact in a locked position and forms a slot (46) for receiving a cord connected to the outlet, and that the power supply is activated only when the cover is locked.

2. The power supply system according to claim 1, wherein the cables (11) are pulled directly on the ground and covered by a cable protection device (30) arranged to resist damage and collision.

3. The power supply system to claim 1 or 2, wherein the cable protection device comprises modules (41) which are secured to the ground surface by fastening devices (32).

4. The power supply system according to any of claims 1 to 3, wherein a module (41) forms a base to a power outlet (12).

5. The power supply system according to any of claims 1 to 3, wherein an inner post (45) which is pressed down in the ground constitutes a base to the power outlet (12).

6. The power supply system according to any preceding claims, wherein the power supply system comprises a control module (39) for control and payment of the power supply service.

7. The power supply system according to any preceding claims, wherein the connection module (36) comprises a card reader (40).

8. The power supply system according to any preceding claims, wherein the low-voltage switchgear (8) is connected to a transformer (7) arranged at the parking surface, the transformer is connected to a high-voltage switchgear arranged at a power grid (2), and wherein the high-voltage switchgear is directly connected to the transformer (7) by a high-voltage cable (5).

9. A method for charging of batteries for an electrically powered vehicle, with a power supply system comprising a plurality of power outlets (12) connected by cables (11) to a low-voltage switchgear (8), wherein each power outlet (12) comprises a post (35) and a connection module (36) supported by the post, c h a r a c t e r i s e d i n that a lockable room (51) comprising at least one power outlet (42) is arranged in the connection module (36), that the room is arranged to accommodate a plug contact connected to the outlet, that the room is restricted by a lockable cover (38), that a slot (51) is formed with the cover in a locked position for receiving a cord connected to the outlet, and that the power supply is activated only when the cover is locked.

10. Use of an installation according to claims 1 to 8, or a method according to claim 9, for charging of batteries for a plurality of electrically powered vehicles temporarily parked at a private or public parking place, wherein a safe handling of a consumer is met.