TIDA-010081: PFC stage

Venkatesh B

Part Number: TIDA-010081
Other Parts Discussed in Thread: UCC28180

Hi ti expert,

Good evening

I am using UCC28180 PFC IC for 1kW EV charger front end.

I have tested PFC circuit alone using Rheostat load(2 nos of Board), switching frequency is 100KHZ.output voltage fine tuned to 415V DC

when i am using same circuit, same PCB board, one Board when turned on,PFC boosted voltage to 415V DC,then i started increasing Rheostat Load gradually,while reaching 1KW of power,Voltage dips to 405V.

same i repeat for board no 2,at 1kw of power,voltage maintains at 415V.

I dont know reason for why this drop since same circuit,same components,same PCB but behaviour is different in two boards.

2. Second doubt is when i given full load then enable PFC operation, driver IC blows off, kindly suggest ways to operate in this condition.

3. Efficiency is 96 to 97% only,is there any way i can increase efficiency further because cumulative efficiency(PFC+LLC) is only 92%(peak),requirement is 95% above

Thank you

venkatesh B

10 months ago

0 Max Wang1 10 months ago

TI__Intellectual 1580 points

Hi,venkatesh B

for your questions,

1, Can you help to check if current limit is triggered for board 1

2, how do you enable the PFC? basically, it is better to start up PFC at light load, and then enable downstream LLC with UVLO pin, this will be safe to make system operate.

3, Can you check the thermal to see which one generate heat most, normally PFC stage efficiency drops with AC line decreasing, so better to check other components such as EMI choke, what's your target efficiency of PFC stage?

Max

0 Venkatesh B 10 months ago in reply to Max Wang1

Intellectual 627 points

Hi,

I am enabling PFC by giving Vcc 12V by control circuit.

Both boards undergone softstart and then gradually increasing the load.(both board working good functionally ecxept this voltage drop)

Thermal I didnt check but both Board loaded for 1.1KW peak power

Targeted efficiency is above 98%(98.5% is good for me)

Thank you

0 Venkatesh B 10 months ago in reply to Venkatesh B

Intellectual 627 points

hi could you please reply me ,so that i can proceed further

+1 Max Wang1 10 months ago in reply to Venkatesh B

TI__Intellectual 1580 points

Hi as i said, can you check your PFC stage if it trigger current limit, other wise there is no reason that same two boards show different voltage, basically you can sawp the inductor or some other circuity for double check

Max

0 Venkatesh B 10 months ago in reply to Max Wang1

Intellectual 627 points

Dear wang,

i will cross check with another board

Thank you

venkatesh

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TIDA-010081: PFC stage