Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B3/00—Line transmission systems
  • H04B3/54—Systems for transmission via power distribution lines
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L5/00—Arrangements affording multiple use of the transmission path
  • H04L5/003—Arrangements for allocating sub-channels of the transmission path
  • H04L5/0044—Allocation of payload; Allocation of data channels, e.g. PDSCH or PUSCH
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B2203/00—Indexing scheme relating to line transmission systems
  • H04B2203/54—Aspects of powerline communications not already covered by H04B3/54 and its subgroups
  • H04B2203/5404—Methods of transmitting or receiving signals via power distribution lines
  • H04B2203/5416—Methods of transmitting or receiving signals via power distribution lines by adding signals to the wave form of the power source
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B2203/00—Indexing scheme relating to line transmission systems
  • H04B2203/54—Aspects of powerline communications not already covered by H04B3/54 and its subgroups
  • H04B2203/5462—Systems for power line communications
  • H04B2203/547—Systems for power line communications via DC power distribution
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B2203/00—Indexing scheme relating to line transmission systems
  • H04B2203/54—Aspects of powerline communications not already covered by H04B3/54 and its subgroups
  • H04B2203/5462—Systems for power line communications
  • H04B2203/5483—Systems for power line communications using coupling circuits
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B2203/00—Indexing scheme relating to line transmission systems
  • H04B2203/54—Aspects of powerline communications not already covered by H04B3/54 and its subgroups
  • H04B2203/5462—Systems for power line communications
  • H04B2203/5491—Systems for power line communications using filtering and bypassing

Definitions

• the periodic interference pulses are caused by the commutation of the current in the rectifier.
• the converter components or valves usually diodes or thyristors, in a rectifier carry the direct current alternately.
• inductances between the valves create a voltage peak, which is associated with voltage increases of the order of magnitude of approximately 400 kV / s. Since the commutation times are determined by the frequency of the AC network, the interference pulses occur in a certain time grid, that is to say periodically.
• the object of the invention is therefore to specify a suitable data transmission method, which can be used in particular in DC voltage power supplies, and to provide an associated device.
• the problem mentioned at the outset is solved in a simple manner by designing the OFDM method in such a way that the OFDM blocks to be transmitted have a length of approximately 85% of the distance between two periodic interference pulses.
• the frequency difference of two carriers must be in an integer ratio to the reciprocal length of the OFDM block.
• ⁇ CU P- d ⁇ P- 1 P- 1 ö P vq N d vQ ⁇ cn ⁇ rt to tr F- ⁇ - 1 ⁇ P. F- P. tr ö H- ⁇ tr P vq H- ⁇ dd cn PJ • ⁇ ti ⁇ rt H ⁇ cn cn ⁇ H- d O ⁇ ⁇ S ⁇ Hl Hi vQ ⁇ rt P- ⁇ P "Hl tr cu tn cd tn vQ ⁇
• Figure 1 is a graphical representation of the time course of a DC voltage for a subway system, Figure 2 and the transmitter part
• FIG. 3 shows the receiver part of a suitable device for data transmission in the case of DC voltage curves according to FIG. 1.
• PLC Powerline Communication
• subways are operated with a nominal DC voltage of 750 V. It is common practice to provide the DC voltage using 12-pulse rectifiers, which in turn are fed by a converter transformer.
• the 12-pulse rectifiers consist of two 6-pulse rectifiers, which in turn are fed by two windings of the converter transformer that are electrically offset by 30 ° from each other.
• the converter transformer is primarily connected to the general energy supply with a mains frequency of 50 Hz.
• the described method can also be used at other frequencies such as Can be used at 60 Hz.
• FIG. 1 shows, by way of example, a measured time profile of the DC train voltage over a period of 20 ms.
• the voltage signal is denoted by 1. It can be seen that the DC voltage is not constant, but rather is subject to fluctuations of up to approximately 80 V.
• the useful signal of a PLC system arriving at the receiver depends on the transmission properties of the route and the distance of the transmitter and is only a few 10 mV to a maximum of about 1 V due to the limited permissible transmission power.
• the data signal is partitioned in such a way that a single data block with a certain safety distance fits between two interference pulses.
• the data signal is thus always transmitted in a fault-free time period, the precise temporal correlation with the interference pulse pattern being established with the combination of threshold switch 33a and subsequent phase-locked loop 33b described above.
• a receiver 30 is formed from a coupling unit 31 for the rail system from FIG. 2, which is followed by a filter 32, an impedance 34 and a short-circuiter 35.
• AGC Automatic Gain Control
• the data are sent to a processing unit 38 for OFDM signals via an A / D converter 37.
• the interference pulses are recorded with the aid of a threshold switch on the network side and fed to a phase locked loop (PLL) for the purpose of jitter suppression as a rectangular guide signal.
• PLL phase locked loop
• the stable synchronizing signal from the phase locked loop in the time grid of the interference pulses is then fed to a the 'short closers 35 and the other processing unit 38 for OFDM signals.
• the short-circuiter thus suppresses the received signal for as long as an interference pulse lasts and releases the receiver input as soon as the interference-free period between the interference pulses begins. Due to the stable synchronization signal, the processing unit 38 for OFDM signals the exact 'temporal position of the known data packets to be processed, can be carried out so that a proper data recovery.
• a switch in the parallel branch can also be used.
• the impedance 34 is not required in this case.
• the interference pulse is e.g. kept away from the OFDM processing unit in that the signal line via an analog switch, e.g. in
• the signal is fed to the amplifier 36 with automatic gain control (AGC), which amplifies it to a level optimally set for the A / D conversion.
• AGC automatic gain control
• the partitioned signals are then combined in the subsequent processing units and decoded in accordance with the prior art.
• the OFDM method known per se is modified by a division, ie a so-called partitioning of the data, in such a way that a transmission takes place only in virtually trouble-free time segments .
• the transmission process is synchronized with the periodic pulse interferer and it is sent exactly between the interference pulses. Accordingly, the detection and masking of the interference pulses takes place in the receiver.
• the partitioned data can be combined.
• the invention has been described above ' specifically for data transmission in a DC voltage supply for subways.
• the invention can also be used in other networks operated with DC voltage, for example in DC voltage networks for the self-supply of switchgear.

Landscapes

• Engineering & Computer Science (AREA)
• Signal Processing (AREA)
• Computer Networks & Wireless Communication (AREA)
• Power Engineering (AREA)
• Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
• Noise Elimination (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=7668046

Family Applications (1)

Country Status (7)

Families Citing this family (44)

Family Cites Families (7)

• 2000
  • 2000-12-20 DE DE10063675A patent/DE10063675C1/de not_active Expired - Fee Related
• 2001
  • 2001-12-06 JP JP2002552265A patent/JP4125956B2/ja not_active Expired - Fee Related
  • 2001-12-06 US US10/451,106 patent/US7161985B2/en not_active Expired - Fee Related
  • 2001-12-06 CN CNA018208487A patent/CN1526223A/zh active Pending
  • 2001-12-06 WO PCT/DE2001/004583 patent/WO2002051089A2/de not_active Ceased
  • 2001-12-06 EP EP01995578A patent/EP1344366A2/de not_active Withdrawn
• 2003
  • 2003-06-19 NO NO20032823A patent/NO20032823L/no not_active Application Discontinuation

Non-Patent Citations (1)

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