| 摘要 |
PURPOSE:To lessen a share of braking power for a power absorber and to decrease the capacity by increasing motor current, raising the switching frequency of a semiconductor power converter, and increasing the losses of the motor and the converter, when a part or the whole of the braking power is absorbed. CONSTITUTION:At the the of the annulment of regenerative braking, control is so performed that required braking power may be generated in a motor 5 by making the output current of an inverter 4 a square-wave approximately, and enlarging its magnitude up to no allowable maximum value. Besides, switching frequency to semiconductor devices constituting the inverter 4 is also increased up to an allowable maximum value. As a result, a share of braking power for a power absorber such as a resistor 91 etc., decreases, since losses generated in the motor 5 and the inverter 4 increase. Consequently, it becomes possible to decrease the capacity of the power absorber such as a resistor etc., and to reduce the size and weight. |
