13.2.35. over_voltage_monitor

This interface defines a fast over voltage monitoring device according to IEC61851-23:2023 6.3.1.106.2 for DC charging. An emergency shutdown needs to be triggered if the DC output voltage is above the limit of Table 103 for 9ms. The actual shutdown needs to be handled in a lower layer outside of EVerest, but this interface sets the correct voltage limit at the start of the session and stops monitoring at the end of the session. The over voltage error should be reported after the actual shutdown was already performed. Once an over voltage error was raised, it should only be cleared when the reset_over_voltage_error command is called. All other errors should be raised/cleared when they occur/are no longer active immediately. The var voltage_measurement_V should be published in regular intervals, e.g. 1 second. It is not used to compare it with the overvoltage threshold setting in EVerest, that has to be done in the OVM device itself. It will only be used to validate that the OVM and the IMD see the same voltage to ensure they are correctly wired to the same charging port. If it is not available in hardware, do not publish the voltage_measurement_V at all.

13.2.35.1. Variables

voltage_measurement_V:number

Measured voltage in V

13.2.35.2. Commands

start:void

Start over voltage monitoring

over_voltage_limit_V:number <required>

Specifies the over voltage threshold [V] (based on IEC61851-23:2023 Table 103) An emergency shutdown should be triggered if the DC output voltage is higher than this value.

stop:void

Stop over voltage monitoring at the end of the power transfer.

reset_over_voltage_error:void

Resets the detection logic to allow for new charging session after an over voltage error occurred. This should clear the over voltage error. If monitoring is still active, it should be stopped.