Yes there is, and it's documented in the Help Centre.

https://superuser.com/help/serial-voting-reversed


> When a single user continually votes (up or down) on many of your
> posts within a short period of time, the system considers these votes
> to be invalid and removes them. 
>
> Such votes will generally be invalidated as part of an automated
> process that runs every day, but may also be invalidated manually by
> the staff after an investigation. When the votes are invalidated, the
> reputation gain or loss from the votes is undone, which results in a
> record in the recipient's reputation history labelled "voting
> corrected".
> 
> 

> **What if I think I'm the victim of voting abuse?**
>
> If you see very unusual votes being targeted at your account, don't worry about it. You should wait at least 24 hours after noticing before becoming concerned, as the automated system should detect it and reverse it for you. If, after 24 hours, you do not see any fix to your reputation, please contact the team using the "contact us" form located at the bottom of any page.