This section describes how you can migrate the existing substation devices from physical to virtual PAC.
Power system protection, automation, and control systems have continuously evolved along with technology. However, the pace of change typically lags mainstream adoption due to the criticality of grid operations and the caution that is generally exercised by utility personnel. This lag can result in a wide variety of device vintages, especially for well established companies, responsible for large service territories, that are therefore unable to act efficiently in their lifecycle management.
This breadth of architecture might encompass electromechanical, solid state, and microprocessor device types.
The transformation that the vPAC Ready Infrastructure brings to the power service provider edge facilitates a significant reduction in physical devices required for operation. It means the footprint required within a site is reduced. Efficient allocation of space for new equipment during an upgrade can be accomplished easily.
There are two types of existing infrastructure to consider:
Traditional secondary connections – devices are wired directly to high voltage apparatus connections (for example, current and voltage transformers, auxiliary position relays).
Digitalization has already occurred – digital translation devices (for example, merging units) are in use to deliver grid measurements and status signals to IEDs (see example in Digitalization in a Substation Bay).
There can be a mix of these infrastructures where only the station bus communications exist (but not process bus). Devices leveraging only the station bus are likely in place to support a lack of PAC centralization (for example, a protection back-blocking scheme), and therefore might not be useful. Alternatively, simple I/O translation devices might exist in support of major equipment (like transformers) which can be useful.
