翻译成英语：有几位30年以上教龄的老师得了奖章

A few teachers with over 30 years teaching experience were awarded medals for their achievement.
这样说才是楼主要表达的意思

Some of thoese teachers who teached more than 30 years got the medals.

Some teachers with more than 30 years'teaching seniority were awarded medals.

A Few teachers with more than 30 years teaching experience got the medal .