POWER SUPPLY DEVICE OF ELECTRIC EXCAVATOR

1 . A power supply device for an electric excavator, the power supply device comprising:

a power supply unit configured to supply power of a battery to an electric motor unit;

a first charging port connected to the power supply unit and configured to supply first external power to the battery;

an on-board charger (OBC) connected to the power supply unit and configured to convert alternating current into direct current when alternating current power is inputted; and

a second charging port connected to the OBC and configured to supply second external power to the OBC,

wherein the power supply unit supplies charging power of the OBC or supplies the charging power of the OBC and power of the battery power to the electric motor unit on the basis of an amount of required power of the electric motor unit and an amount of charging power of the OBC.

2 . The power supply device of claim 1 , wherein the first charging port is a high-speed charging port.

3 . The power supply device of claim 1 , wherein the second charging port is a low-speed charging port.

4 . The power supply device of claim 1 , wherein the power supply unit compares the amount of required power of the electric motor unit with the amount of charging power of the OBC,

wherein the power supply unit supplies the charging power of the OBC and the power of the battery to the electric motor unit when the amount of required power is larger than the amount of charging power of the OBC, and

wherein the power supply unit supplies the charging power of the OBC to the electric motor unit and stores, in the battery, the charging power of the OBC remaining after the supply of the charging power when the amount of required power is equal to or smaller than the amount of charging power of the OBC.

5 . The power supply device of claim 1 , further comprising:

a battery management system (BMS) configured to check whether the excavator is turned on and disconnect a connection from the first charging port to the power supply unit in a state in which the excavator is turned on.

6 . The power supply device of claim 1 , wherein the first charging port is disposed at a lateral side of a cabin of the excavator.

7 . The power supply device of claim 1 , wherein the second charging port is disposed at a rear side of a cabin of the excavator.

8 . The power supply device of claim 1 , wherein the electric motor unit comprises a first inverter and a first motor, and the first motor is connected to a hydraulic pump.

9 . The power supply device of claim 8 , wherein the electric motor unit further comprises a second inverter and a second motor, and the second motor is connected to a turning speed reducer.

10 . The power supply device of claim 8 , further comprising:

a fan motor; and

a converter connected between the fan motor and the power supply unit,

wherein the power supply unit compares a sum of the amount of required power of the fan motor and the amount of required power of the electric motor unit with the amount of charging power of the OBC,

wherein the power supply unit supplies the charging power of the OBC and the power of the battery to the electric motor unit and the fan motor when the sum of both the amount of required power of the fan motor and the amount of required power of the electric motor unit is larger than the amount of charging power of the OBC, and

wherein the power supply unit supplies the charging power of the OBC to the electric motor unit and the fan motor and stores, in the battery, the charging power of the OBC remaining after the supply of the charging power when the sum of the amount of required power of the fan motor and the amount of required power of the electric motor unit is equal to or smaller than the amount of charging power of the OBC.

11 . A power supply device for an electric excavator, the power supply device comprising:

a power supply unit configured to supply power of a battery to an electric motor unit;

a first charging port connected to the power supply unit and configured to supply first external power to the battery;

an on-board charger (OBC) connected to the power supply unit and configured to convert alternating current into direct current when alternating current power is inputted; and

a second charging port connected to the OBC and configured to supply second external power to the OBC,

wherein the first charging port is a high-speed charging port, and the second charging port is a low-speed charging port,

wherein the power supply unit compares an amount of required power of the electric motor unit with an amount of charging power of the OBC,

wherein the power supply unit supplies charging power of the OBC and power of the battery to the electric motor unit when the amount of required power is larger than the amount of charging power of the OBC,

wherein the power supply unit supplies the charging power of the OBC to the electric motor unit and stores, in the battery, the charging power of the OBC remaining after the supply of the charging power when the amount of required power is equal to or smaller than the amount of charging power of the OBC,

wherein the electric motor unit comprises a first inverter, a second inverter, a first motor, and a second motor, and

wherein the first motor is connected to a hydraulic pump, and the second motor is connected to a turning speed reducer.