To accurately estimate actual generated electric power or power consumption of a power generator.

The control device is provided with a means for calculating charging/discharging power correction value cPb, on the basis of the deflection dPb between a charging/discharging power target value tPb and a charging/ discharging power actual value rPb, a means for calculating a power generator power target value tPg on the basis of a drive motor power target value tPm, the charging/discharging power target value tPb and the charging/discharging power correcting value cPb, a means for calculating a power generator command value on the basis of the power generator power target value tPg, means (B12, B13) for calculating a power generator power estimation value ePg, means (B14, B15, B19, B20, B26, B27) for calculating as a drive motor power limit value 1Pm, a value in which the power generator power estimation value ePg is corrected by the charging/discharging power correction value cPb, and means for calculating the drive motor command value sTm so that the electric power consumed or regenerated by the drive motor conforms to either of the drive motor power target value tPm or the drive motor power limit value 1Pm.