All court pleadings, including a Petition for PFA, must have a Verification of the factual averments contained in the pleading. There are consequences for knowingly filing a pleading with the court which you know to be false.
Be warned however that the courts will always err on the side of a victim of domestic violence and it will be extremely difficult to prove that the PFA is completely frivoulous. While you may disagree with the facts, it is hard to prove that the Petioner has lied completely. Once obvious exception is that you have an alibi and were no where remotely close to that person when the alleged abuse occurred.