Cant we convert directly sunlight into RF?( i mean is there no technology that can do this, so that need of PV array will be gone).

We want energy on Earth and we want a lot of it. To do that we need to capture energy from the sun and somehow output it ON earth, using available resources. Problems on earth are considerable, and he biggest problem on the Earth’s surface is that the more PV (of whatever kind we implement the more surface space we use, and the higher the cost of required raw materials will become. So in effect bootstrapping more (clean!) energy ON the earths surface derivative from the sun is costly and will only get more costly as time goes along. People like Ray Kurzweil disagree with this, but I am not fully swayed by his arguments. You decide.

Things in space are different. Once you establish an infrastructure to yield orbital energy collection systems, the price of mineral ore production will drop like a stone. There are a lot of asteroids out there. The moon is effectively one giant strip mine. I’d go straight for near-earth industrialization, but yes, the cost is very steep. My point is however that with robotics in a decade it will be so easy to mine ore, turn it into something that converts energy, the add a lot of those things, that no matter how inefficient they are, the investment in capital will yield so much energy output to Earth’s surface that you’d be making trillions in raw profit.

Is there any other thermal management system other than dual phase transport system?

It’s plain economics. If the system is run by ten engineers, at an investment of 100 billion, and a ground base like Guyana ESA that runs at a few billion a year, and each year interplanetary automated systems just grab ore, refine it into stupid victorian pig iron heat exchangers launched from the lunar surface with 1960s tech coilguns, and all that just keeps adding gigawatt at a rate of one a week – you’d be at a break even point very very quickly. Inefficient doesn’t mean you lose money in such an environment – there is just so much material and energy out there in space you can be wasteful for a while.

if some design of solar power satellite is to be considered for study which one is most favourable and which factors are taken into considerations while designing these satellites?

There are many studies. My personal favorites are Shimizu. I think those guys really get it.

where can i get to read about more technological concepts related to thermal and structural analysis of space solar satellites?

I forwarded this post to a few friends… they may get in touch with you 🙂