i am a student and currently writing a paper on past participle.
can anyone help me to identify errors and problems international students might have with this tense?
Well, first of all, a past participle isn't a tense -- it's a participle derived from a verb which is used, amongst other things, to indicate the perfect aspect. Most grammar books will refer to the "perfect tenses", which is, strictly speaking, inaccurate, but simplifies matters a bit for the student.
International students -- depending on what their first language is, of course -- generally have problems with the difference between the present perfect and the simple past. For example, although German has the same tenses (and they were originally used in a similar way to the English equivalents), the choice between them is now largely a matter of style.
As for the participle itself, the biggest problem I've ever encountered is with the irregular forms -- students wanting to write "I have cutted", for example. When used as an adjective, there is sometimes some confusion between the past and present participles, e.g. confusion between "boring" and "bored" and between "interesting" and "interested" ("I am interesting in stamp-collecting" being a very common error).