System and method for transferring electric energy to a vehicle
The invention relates to a system for transferring electric energy to a vehicle, in particular to a track bound vehicle such as a light rail vehicle, wherein the system comprises an electric conductor arrangement for producing an alternating electromagnetic field and for thereby transferring the energy to the vehicle, the electric conductor arrangement comprises at least two lines, wherein each line is adapted to carry a different one of phases of an alternating electric current, the conductor arrangement comprises a plurality of segments, wherein each segment extends along a different section of the path of travel of the vehicle, each segment comprises sections of the at least two lines and each segment can be switched on and off separately of the other segments.
1. A system for transferring electric energy to a vehicle comprising:
an electric conductor arrangement for producing an alternating electromagnetic field and for thereby transferring the energy to the vehicle, wherein
the electric conductor arrangement comprises at least two lines, wherein each line is adapted to carry a different one of phases of an alternating electric current,
the conductor arrangement comprises a plurality of segments, wherein each segment extends along a different section of the path of travel of the vehicle, each segment comprises sections of the at least two lines and each segment can be switched on and off separately of the other segments,
the conductor arrangement is arranged in such a manner that at least two consecutive segments can be operated at a time, wherein corresponding lines for carrying the same phase of the alternating current in the consecutive sections are connected in series to each other, and
a switch or an arrangement of switches located at an interface between two consecutive segments of the conductor arrangement, wherein
the switch or the arrangement of switches is operated in such a manner that, if only one of the two consecutive segments is operated at the same time, the lines of the segment which is operated are connected to a common star point or to a power supply system, and that, if both consecutive segments are operated at the same time, the corresponding lines of the consecutive segments are connected in series to each other.
2. The system of claim 1 , wherein the segments are shorter than the length of a vehicle in the travel direction and wherein the system is adapted to operate segments only if a vehicle is occupying a respective section of the path of travel where the segment is located.
3. The system of claim 2 , wherein the system is adapted to switch on the segments only if a vehicle is fully occupying a respective section of the path of travel.
4. A method for transferring electric energy to a vehicle comprising:
producing an electromagnetic field by an electric conductor arrangement located along the track thereby transferring the electric energy to the vehicle, wherein
the electromagnetic field is produced by conducting at least a first phase of an alternating current in a first line of the electric conductor arrangement and by conducting at least a second phase of the alternating current in a second line of the electric conductor arrangement,
the electric conductor arrangement segments of the conductor arrangement are switched on and off separately of other segments in order to generate the electromagnetic field in a restricted region of the path of travel of the vehicle, wherein each segment extends along a different section of the path of travel of the vehicle and wherein each segment comprises sections of the at least two lines, and
if only one of the two consecutive segments is operated at a time, the lines of the segment which is operated are connected to a common star point or to a power supply system, and wherein, if the two consecutive segments are operated at the same time, corresponding lines for carrying the same phase of the alternating current in the consecutive segments are connected in series to each other.
5. The method of claim 4 , wherein the lengths of the segments along the path of travel are shorter than the length of a vehicle in the travel direction and wherein segments are switched on only if a vehicle is already occupying the respective section of the path of travel along which segment extends.
6. The method of claim 5 , wherein the segments are switched on only if a vehicle is fully occupying the respective section of the path of travel.
7. The method of claim 5 , wherein the occupation of a respective section by a vehicle is detected by detecting a voltage and/or a current in the segment or in a separate loop, which voltage and/or a current is caused by inductive coupling of the vehicle to the line segment and/or which is caused by electromagnetic fields produced by the vehicle.
8. The method of claim 5 , wherein a segment is switched on before a receiving device of a vehicle for receiving the transferred energy enters the section of the path of travel along which the segment extends.