Multi-input charging system and method using motor driving device
A multi-input charging system and method using a motor driving device: the system includes a first inverter including a plurality of first switching elements, a second inverter including a plurality of second switching elements, a battery connected to a charging power input terminal or one end of the second inverter through a charging switch, and a controller configured to directly charge the battery through the charging power input terminal by selectively connecting the charging switch when a battery charging mode is started, and when connection of the charging switch is impossible, control the first switching elements and the second switching elements such that the charging power input terminal and the battery are connected through the first inverter, a motor, and the second inverter in a bypass manner.
1. A multi-input charging system using a motor driving device, comprising:
a motor having a plurality of windings respectively corresponding to a plurality of phases;
a first inverter including a plurality of first switching elements and having a first end connected to a charging power input terminal to which charging power is inputted from outside, and a second end connected to a first end of each of the plurality of windings;
a second inverter including a plurality of second switching elements and having a first end connected to a second end of each of the plurality of windings;
a battery connected to the charging power input terminal or a second end of the second inverter through a charging switch; and
a controller configured to connect the charging switch to directly charge the battery through the charging power input terminal based on a voltage of the charging power when a battery charging mode is started, or disconnect the charging switch and control the first switching elements and the second switching elements such that the charging power input terminal and the battery are connected through the first inverter, the motor, and the second inverter in a bypass manner, thereby charging the battery at a reduced voltage.
2. The multi-input charging system according to claim 1 , wherein the controller directly charges the battery through the charging power input terminal by connecting the charging switch when the battery charging mode is started and voltage drop of the charging power is not required, and when voltage drop of the charging power is required, the controller releases the charging switch, drops a voltage of the charging power through the first inverter and the second inverter, and charges the battery with the dropped voltage.
3. The multi-input charging system according to claim 2 , wherein the controller attempts to connect the charging switch when voltage drop of the charging power is not required, and when connection of the charging switch is impossible, the controller controls the first switching elements and the second switching elements such that the charging power input terminal and the battery are connected through the first inverter, the motor, and the second inverter in a bypass manner.
4. The multi-input charging system according to claim 1 , wherein the controller connects top switching elements of the first and second switching elements such that the charging power input terminal and the battery are connected through the top switching elements of the first inverter, the motor, and the top switching elements of the second inverter in a bypass manner when connection of the charging switch is impossible.
5. The multi-input charging system according to claim 1 , wherein the charging switch is arranged between the charging power input terminal and the battery, and the second end of the second inverter is connected between the charging switch and the battery.
6. The multi-input charging system according to claim 1 , wherein the controller drops the voltage of the charging power through the first inverter, the motor, and the second inverter and charges the battery with the dropped voltage when a voltage of the charging power is greater than or equal to a voltage level preset to a battery chargeable level.
7. The multi-input charging system according to claim 6 , wherein, when the controller drops the voltage of the charging power and charges the battery with the dropped voltage, the controller performs pulse width modulation control such that the plurality of first switching elements included in the first inverter is turned on/off depending on a duty ratio.
8. The multi-input charging system according to claim 6 , wherein, when the controller drops the voltage of the charging power and charges the battery with the dropped voltage, the controller performs control such that top switching elements among the plurality of second switching elements included in the second inverter are connected.
9. A multi-input charging method using the multi-input charging system using the motor driving device of claim 1 , comprising:
receiving, by the controller, a voltage of charging power input to the charging power input terminal;
determining whether to directly charge the battery or to drop the received voltage of the charging power and charge the battery with the dropped voltage based on the voltage of the charging power received by the controller;
connecting the charging switch through the controller when the battery is directly charged through the charging power input terminal according to a determination result; and
controlling the first switching elements and the second switching elements, by the controller, such that the charging power input terminal and the battery are connected through the first inverter, the motor, and the second inverter in a bypass manner when connection of the charging switching is impossible.
10. The multi-input charging method according to claim 9 , wherein the connecting of the charging power input terminal and the battery through the first inverter, the motor, and the second inverter in a bypass manner comprises connecting top switching elements of the first and second switching elements, by the controller, such that the charging power input terminal and the battery are connected through the top switching elements of the first inverter, the motor, and the top switching elements of the second inverter in a bypass manner.