Hi,
Go to Alarm -> Trap Management -> Trap Definition.
In the search window look for the trap OID: 1.3.6.1.4.1.25506.8.35.
You should see a number of traps in relation with power supplies, temperature, etc, icluding yours.
Ensure that the trap has a sverity enough to appear in your browser (indeed higher then INFO).
If they are not there load the "H3C Ethernet Switch" trap MIB file (avaialble on HPE site)
then;
Go to Alarm -> Trap Management -> Trap to Alarm
Ensure that the "H3C Ethernet Switch" is ENABLE with default rule.
You might have another issue, but al least this is worth to check.
Cheers
Ray