Dear Tushar,

It is not a book, but maybe will give you some ideas.

There is an example from Matlab/Simpowersystems that uses average modeling for converters.

The link is attached to this answer.

"The average model (discrete) such as the one presented in this example. In this type of model the IGBT Voltage-sourced converters (VSC) are represented by equivalent voltage sources generating the AC voltage averaged over one cycle of the switching frequency. This model does not represent harmonics, but the dynamics resulting from control system and power system interaction is preserved. This model allows using much larger time steps (typically 50 microseconds), thus allowing simulations of several seconds."

http://www.mathworks.com/help/physmod/sps/examples/wind-farm-dfig-average-model.html?searchHighlight=wind%20farm&refresh=true

Fundamentals of Power Electronics by Erickson. 

Dear Tushar

Yes....You can find the average modelling of all type of converters in the book "Fundamentals of Power Electronics" by Erickson.

Hello Tushar,

You could also find information in "Power Electronics, Circuits Devices and Applications" by Muhammad H. Rashid

Hi,

I think this book is very useful:

"Power Electronic Converters Modeling and Control with Case Studies", by Seddik Bacha

you can see your problem in FUNDAMENTALS OF POWER ELECTRONICS BY ERIKSON