In this case, can it be considered only 1 talaq since the man had no knowledge and no intention?
بسم الله الرحمن الرحيم
Yes, in the above mentioned case all the three talaqs shall be counted. According to Shariah, ignorance is not an excuse in Shariah commandments. All the three talaqs took place on your wife and she became mughallazah (fully separated). In case you want to keep your wife again, Shariah halalah is needed.
Allah knows Best!
Darul Uloom Deoband
This answer was collected from the official ifta website of Darul Uloom Deoband in India.