i can increase steem power by transfering sbd to steem right

Your statement is incorrect because "steem" and "steem power" are really 2 different things. You could, however, convert your SBD to steem and then "power up" the steem to get "steem power". Going directly from SBD to "steem power" is not possible, as far as I know.

"Steem" it different from "steem power" and "SBD" is a third currency. You can buy "steem power" one-for-one with steem. it is called powering up. Furthermore, you can buy "steem" with SBD at the going rate, but you can't "power up" SBD or buy "steem power" directly with SBD.

The diagram below depicts what can be converted to what. The Internal Market is where you can trade steem for SBD and vice versa, but "steem power" has nothing to do with the Internal market.

I hope this helped.

*FYI as you go deeper, there are also "vests", but that adds another level of complexity which you probably don't need to know now, so I won't go into that, but if you hear about them you will not be totally blindsided. You can function perfectly without worrying about vests.