Mitsubishi Electric Power Products Inc (MEPPI)  is a worldwide leader in the development, design, and manufacturing of large electrical generators and associated excitation systems. MEPPI has supplied many excitation systems for power plants using nuclear, steam, and hydro turbines. MEPPI has supplied more than 200 thyristor based static excitation systems with superior performance and reliability for new generators and to replace older excitation systems on existing generators. In the United States, one of Mitsubishi's specialties is to replace existing rotating exciters with one of its static excitation systems to improve the performance, reliability, and maintenance of existing units.