| CPC D06F 34/08 (2020.02) [D06F 33/42 (2020.02); D06F 33/47 (2020.02); D06F 33/48 (2020.02); D06F 34/34 (2020.02); D06F 37/30 (2013.01); D06F 39/08 (2013.01); D06F 39/082 (2013.01); D06F 39/085 (2013.01); D06F 2103/18 (2020.02); D06F 2103/42 (2020.02); D06F 2103/48 (2020.02); D06F 2105/08 (2020.02); D06F 2105/58 (2020.02)] | 20 Claims |

|
1. A washing machine comprising:
a washing tub;
a drain pump configured to drain water in the washing tub;
a pump motor configured to operate the drain pump;
an inverter circuit configured to supply a driving current to the pump motor to operate the drain pump; and
a controller configured to:
control the inverter circuit to supply pre-set reference power to the pump motor based on a start of a draining course;
determine reference revolutions per minute (rpm) based on an average value of an operating rpm of the pump motor during a preset period of time in which the pre-set reference power is supplied to the pump motor; and
in response to the determining of the reference rpm, control the inverter circuit to operate the pump motor at the determined reference rpm.
|