logically what you do is incorrect while it means that one node has two different voltages which is imposible.

you should use small resistor as Shady has already mentioned or check your circuit for possible logical mistakes.

If you don't insert a small inductance/resistance between the two sources, in case of a tiny difference between the voltages, one source must be able to provide infinite current which is not possible.

Thanks all for the suggestions. The simulation works now after adding small resistance in series with the voltage sources.

Thank you once gain.

Connect the circuitry by adding a small rate resitors between the voltage source and the ground

Connecting two ideal voltage sources is equivalent to connect two ideal current sources un series. Ideal current and voltage sources are "ideal" circuit components, capable of holding its current por voltage, respectively. I agree with all the previous comments regarding the inclussion of a small series resistor, nevertheless there is still a more relevant cuestión: why do you need to simulate two voltage sources in parallel? Eventually you are trying to simularé two synchronised parallel connected energy sources, un such a case 

I believe you need to recheck your model for any inconsistancies in the node voltages. Even if u add some random resistors in your model. Addition of dummy resistors may also adversely affect the performance of your system. Therefore, I recommend you to revisit the modeling and find out the reason for the voltage unbalance in a node.

How about studying a little before posting such question?

@ Fernando: Sir it will be taken care from the next post. Their can be some occasions where one misses a basic concept while implementing a complex project. I belief this forum can help us in identifying those missing elements too.

Please pardon me if this post has wasted your time.

Amit Kumar Roy

No problem. :-)

Use series resistor

I suggest you to add a very small resistor in series with each voltage source, as Shady and Imran have proposed. It must solve your problem.

Regards!

Dear Roy , 

You must add a series resistor and ground model . ground is reference point (no error) .

Best regard . 

@ Andrés Pavas: Yes sir, the origin of my question basically arises when I wanted to synchronized two Renewable energy sources together such that the power can be shared from either of them for various load demands.

Dear Amit Kumar Roy,

you simulation almost correct, you just need add a v.small resistance with ideal voltage source in series. Here is a model attached for you to get the batter understanding.

Thanks Mr. Waqas for your kind suggestions.