As per the IEC61850 standard, the Sepam provides an XCBR Logical Node which publishes the Circuit Breaker position as 2 binary values, which gives a total of 4 possible states.

In other words, one bit gives the "CB Closed" status, which is either 0 or 1, and the second bit is used to store the "CB Open" status, which is also either 0 or 1.

For the sake of discussion, let us define the least-significant bit as the "CB Closed" status.  So, when Sepam detects that the CB is closed, the Pos.stVal value should be [ 0  1 ].

Conversely, when the CB is open, the Pos.stVal value should be [ 1  0 ].  During the course of a CB Close or CB Open operation, this value will pass through the intermediate state of [ 0  0 ], for the very brief time period when the CB is detected as being neither closed, nor open.

For an IEC61850 client, passing through this intermediate state can lead to additional events (e.g., triggered upon a data change criteria) appearing in the Event Buffers, which can be undesirable.

Some relays, such as the MiCOM P40 series, provide a setting which allows the user to decide whether or not these "intermediate states" should be suppressed.

However, as of the latest firmware release for the Sepam ACE850 (V2.2.20019 at the time of this writing), the Sepam does not provide any setting to suppress these intermediate states.  So, at this time, for end-users who wish to avoid having extra events being recorded, the only solution for the time being is to perform the filtering at the SCADA software level.


AEDL3

Released for: Schneider Electric Philippines