By Tomasz Piasecki

The model of prepayment sales was originally derived from the specific needs of electricity sellers. The prototype model was based on the prepayment meter equipped with internal contactor, special billing software and hardware generator of codes carrying information about the purchased energy. The codes were entered into the meter manually by means of a keypad.

The continuation of this model’s development was the enhanced integration of the prepayment system with other applications, which results in improved functionality and process automatisation. A centralised code generator as a service enables the customer to buy electricity not only via the network of sales terminals, but also by automated vending machines (Energomats), Internet and SMS.

APATOR SA has a long tradition in the development of the electricity prepayment system with over 200,000 prepay meters installed in Polish utilities. Its final shape is LEWsystem APATOR, the main elements of which are:

  • Autonomous LEW intelligent prepayment meters
  • Hardware code generator for both energy and technical codes
  • Software which consists of several modules:
    • LEW-Generator – for energy and technical code distribution in customer offices
    • LEW-Energomat – for energy code distribution in automated vending machines (Energomats)
    • LEW-Terminal, LEW-Internet, LEW-Energofon, LEWSMS, LEW-Karta – for energy code distribution via networks of external operators
    • LEW-GSMserwis – for technical code distribution and technical order handling.

The development of customer requirements was followed by the automatisation of the data reading process (AMR). Along with growth in technical sophistication and a reduction in cost of communication with the meter, the main function of remote reading has been further upgraded with mechanisms of intelligent meter management (AMM/AMI).

In order to fulfil these needs, APATOR SA has designed an AMI system named AMRsystem APATOR. The distinguishing feature of the system is a fully bidirectional communication protocol, which allows many metering network infrastructure management orders to be processed simultaneously:

  • Remote reading of meter data
  • Control of internal contactor (disconnect/reconnect)
  • Remote meter configuring
  • Handling of the critical messages generated by the meter.

A wide range of transmission media allows the customer to choose the optimum communication technology:

  • Wireless transmission – Radio transmission in SRD bands (433 MHz and 868 MHz); GSM; Wireless local networks (WLAN – TCP/IP, Bluetooth)
  • Wired transmission – PLC; M-BUS; Ethernet (LAN – TCP/ IP).

Approximately 3,000 AMI meters have been installed to date in about a dozen pilot projects in Poland and elsewhere.

Based on experience with both systems – prepayment and remote reading – new possibilities are apparent from combining the functionalities of both systems:

  • Information about the purchased energy in the prepayment system can be delivered automatically to the meter, which eliminates the need to enter the information into the meter manually. Note the ‘traditional’ way of entering the information manually is still possible, which is crucial during transmission system failures
  • Co-existence of both systems improves the flexibility of calculating the energy consumption, e.g. in the situation when the prepayment system is based on currency calculation, the information about energy prices can be automatically transferred via the system to the meter
  • Current analysis of critical errors received by the AMI class system (e.g. overloading messages) can trigger certain processes in the billing system (e.g. cancelling the discount or decision about disconnecting), which can cause modification in the prepayment sales system.

On account of the advantages resulting from the coexistence and integration of prepayment and remote reading systems, the future development of this type of service can be expected. The integration of autonomous systems like LEWsystem APATOR and AMRsystem APATOR creates fully reliable co-existence and convenience in operation.