| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a ship driving device which can accurately protect a braking resistor with a relatively simple circuit configuration, and a method of protecting the braking resistor for the device. <P>SOLUTION: A ship driving device comprises: a converter 2 that converts AC voltage fed from a generator into DC; a DC capacitor 3 that smooths output voltage of the converter 2; an inverter 4 that converts the converter output into AC voltage and drives an AC motor 5; a series circuit of a braking resistor 7 and a semiconductor switch 6, which is connected in parallel to the output of the converter 2 so as to absorb regenerative power at the time of braking of the AC motor 5; a temperature detector 8 that detects temperature of the braking resistor 7; and a current detector 9 that detects current flowing through the braking resistor 7. The device obtains an overheat protection output for protecting the braking resistor 7 when the magnitude of current that is detected by the current detector 9 for a predetermined first monitoring time exceeds a predetermined first threshold value or the temperature that is detected by the temperature detector 8 exceeds a predetermined threshold value. <P>COPYRIGHT: (C)2013,JPO&INPIT |
