The purpose of the invention is to provide an
inverter-driven
dynamo electric machine and
system for the same having high reliability and high efficiency such that even in the case of
inverter pulse voltages having high dv / dt, generation of shaft voltages and generation of shaft currents causing electric
corrosion of a bearing with the generation of the shaft voltages are suppressed, thereby keeping the bearing free of electric
corrosion.The purpose of the invention is achieved by the following method. That is, the purpose is achieved by an
inverter-driven
dynamo electric machine and
system for the same including at least one
machine support bearing which supports a shaft of a rotor, and one
electric discharge bearing which discharges the
voltage generated in the shaft of the rotor, wherein a bearing having a lower
dielectric breakdown voltage between an inner ring and an outer ring than that of the
machine support bearing is used as the
electric discharge bearing.Accordingly, this can provide an inverter-driven
dynamo electric machine and
system for the same having high reliability and high efficiency such that the bearing is not electrically corroded with respect to the inverter
pulse voltage.