The protection relay's extensive self-supervision system continuously supervises the relay’s software, hardware and certain external circuits. It handles the run-time fault situation and informs the user about a fault via the LHMI, the relay's main unit power module Ready LED and through the communication channels. The target of the self-supervision is to safeguard the relay’s reliability by increasing both dependability and security. The dependability can be described as the relay’s ability to operate when required. The security can be described as the relay scheme’s ability to refrain from operating when not required. The dependability is increased by letting the system operators know about the problem, giving them a chance to take the necessary actions as soon as possible. The security is increased by preventing the relay from making false decisions, such as issuing false control commands.
There are two types of fault indications.
- Internal faults
- Warnings
Warnings are indications of less severe situations which can also be caused by external reasons such as a missing relay configuration.
The self-supervision page is available under . The self-supervision page has the Internal fault and Warning indications. In normal operation, ALL OK is displayed for the Internal fault and Warning indications. The self-supervision also controls the status of IRF output relay. The IRF output relay is energized under normal conditions and de-energized under internal fault conditions.
In addition, the boot reason is available in the audit trail events in Event Viewer in PCM600 under the Security events.