"I really feel it is time to have a good Indy 500 finish, I really do," he said.
"With the things that have happened over the last few years, I feel it's time to have a good finish - which is a win."
Power's main obstacle in years past has been his less-than-stellar form on oval circuits.
A dominant force in the IndyCar's road course formats, Power only has two race wins on the American-style speedways.
With the Indy 500 being the first oval course race of the season, Power admitted the lengthy build-up to the event will be crucial.
"It's a lot different," he said.
"The way you race here is a lot different with the drafting. It's pretty close quarters all the time.
"We did a bit of race work today. I think it's important to get some race stuff in because you get to the end of the week and you just think about qualifying, which pays big points too, so you have to be pretty on it for that."
Compatriot Ryan Briscoe begun preparations for his ninth Indy 500 with 15 laps on Sunday, notching a top speed of 219.745 miles an hour (353.57km/h).
The third Australian in the Indy 500 field, Victorian James Davison, is yet to hit the track.
Due to a limited budget, the KV Racing Technology driver won't run his first practice laps until Thursday's session ahead of his debut performance in the 500-mile race.
"It's been my childhood dream to race in and win the Indy 500," third-generation racer Davison said.
"I have had to work very hard and persevere to get here with KV Racing Technology. Finally, it's arrived and I have a fantastic opportunity with the reigning Indianapolis 500 champion team.
"I feel I have the best of chances to do well."
The Indy 500 practice continues until Friday before qualifying gets underway on Saturday.
The 98th Indianapolis 500 will be run on Monday (AEST).
-AAP
