After the generator, the second most important part of the power station is the tariff metering system, because it converts produced energy into money, allowing the plant to invoice and get paid.
Once the turbine has burned the gas and the generator has produced electricity, everything that follows depends on correct metering. If the produced energy is not measured correctly, it cannot be settled correctly. If it cannot be settled correctly, it cannot be invoiced. At that point, all effort invested in operating the plant does not result in revenue.
In many power stations, tariff meters installed in the 1990s and early 2000s are still in operation. At the time of installation, they fulfilled their role. Today, they are difficult to calibrate, hard to maintain, and often no longer supported by the manufacturer. Spare parts are unavailable, and replacement becomes necessary.
Replacing tariff meters introduces a new challenge. Modern meters use different protocols, different addressing, and different communication methods. They do not match what existing control systems were originally designed to accept. Direct integration would require changes to the existing DCS or SCADA system, which is usually not acceptable.
At the same time, most of the primary equipment can remain unchanged. Current transformers and voltage transformers are still suitable and continue to provide correct signals. The issue is not the measurement itself, but how the data is communicated.
To bridge this gap, a gateway is introduced between the new meters and the existing control system. On one side, it communicates with the meters using their native protocols. On the other side, it presents the data in exactly the same way as expected by the existing DCS or SCADA system. From the control system point of view, nothing changes. No logic is modified and no engineering intervention is required.
Once the data is available in the gateway, it can also be used for reporting. In addition to feeding the control system, the same data can be prepared for reporting purposes and used directly by operators and commercial teams. Reporting outputs can be generated at the required interval, whether minute-based, six-minute-based, or according to other contractual requirements, and opened directly in standard office tools.
Physical integration is just as important as data integration. Existing wiring from current and voltage transformers is reused. The same signals are split and connected to the new meters. No changes to CT, VT, or field wiring are required.
Because tariff meters are part of the revenue chain, physical sealing is mandatory. The design must ensure that no manipulation is possible, either by direct access to the meter or through communication interfaces. All revenue-related components remain protected by physical seals.
The gateway hardware must be industrial-grade and designed to fit into existing cabinets. It must operate reliably in a power plant environment and be compact enough to be installed without requiring cabinet modifications. Standard industrial computers are used, built from off-the-shelf components. There is no vendor lock-in. Media converters and related components are standard industrial devices.
And of course you can’t change all the meter and the same time. Therefore the product has to be Future proof – New additional metres, and even some other equipment might be a added by simply configuring excel spreadsheet
Cybersecurity requirements are addressed by design. The gateway operates with strict firewall rules. Interfaces are closed by default. Isolation is enforced. Any connection toward the IT environment is controlled and unidirectional
This approach allows tariff metering systems to be modernized without changing the existing DCS or SCADA system, without disturbing revenue-critical wiring, and without putting the profitability of the plant at risk.
