
18-6 Power Electronics and Motor Drives
battery technologies: polysulde bromide (PSB), vanadium redox (VRB), zinc bromine (ZnBr),
and hydrogen bromine (H-Br) batteries. However, batteries contain heavy metals, such as Cd
and Hg, may cause environmental pollution. A large majority of UPS designs use a characteristic
constant-voltage charging system with current limit.
• Flywheels. is system is essentially a dynamic battery that stores energy mechanically in the form
of kinetic energy by spinning a mass around an axis. e electrical input spins the ywheel rotor
and keeps it spinning until called upon to release the stored energy through a generator ...