Apparatus for protecting battery pack
An apparatus for protecting a battery pack is configured to release reverse connection of the battery pack by detecting the reverse connection of the battery pack even in a case where the reverse connection of the battery pack is not detected through a battery pack controller.
1. An apparatus for protecting a battery pack, comprising:
a battery pack including a negative terminal, a plurality of positive terminals, and a plurality of battery cells, the negative and positive terminals being connected to a power conversion device, and the plurality of battery cells being configured to be charged by power supplied through the power conversion device;
a plurality of latch relays connecting the plurality of positive terminals and the plurality of battery cells so that connection of the positive terminals and the battery cells can be individually released;
a reverse connection releasing unit configured to determine whether the battery pack has been reversely connected to the power conversion device, and when it is determined that the battery pack has been reversely connected to the power conversion device, to generate a reverse connection detection signal, and to transmit a turn-off signal to the plurality of latch relays; and
a battery pack controller configured to transmit the turn-off signal to the plurality of latch relays when the reverse connection detection signal is applied from the reverse connection releasing unit.
2. The apparatus of claim 1 , wherein the reverse connection releasing unit comprises:
a reverse connection detector configured to determine whether the battery pack has been reversely connected to the power conversion device, based on a voltage of the negative terminal and voltages of the positive terminals, and when it is determined that the battery pack has been reversely connected to the power conversion device, to output the reverse connection detection signal; and
a relay controller configured to execute turn-off of the latch relays when the reverse connection detection signal is applied to an input terminal thereof, by transmitting the turn-off signal to the plurality of latch relays.
3. The apparatus of claim 2 , wherein the reverse connection detector is configured to output the reverse connection detection signal when 0 V is applied to at least any one of the plurality of positive terminals and an output voltage of the power conversion device is applied to the negative terminal.
4. The apparatus of claim 2 , wherein the reverse connection detector is configured not to output the reverse connection detection signal when an output voltage of the power conversion device is applied to the plurality of positive terminals and 0 V is applied to the negative terminal.
5. The apparatus of claim 2 , wherein the reverse connection detector comprises:
a first switching element configured to be connected to negative ends and positive ends of the battery cells connected to each other in parallel, and to turn on a second switching element when an output voltage of the power conversion device is applied to the negative ends of the battery cells and 0 V is applied to a positive end of at least one of the battery cells; and
the second switching element being configured to apply the reverse connection detection signal to the relay controller when the second switching element is turned on by the first switching element.
6. The apparatus of claim 5 , wherein the first switching element is an NPN transistor comprising:
first base terminals to which the negative ends of the battery cells are connected;
first ejector terminals connected to the positive ends of the battery cells through a diode; and
a first collector terminal connected to a second base terminal of the second switching element.
7. The apparatus of claim 6 , wherein the second switching element is a PNP transistor comprising:
the second base terminal connected to the first collector terminal;
a second ejector terminal connected to a regulator, to which the reverse connection detection signal is applied from the regulator; and
a second collector terminal connected to the relay controller.
8. The apparatus of claim 2 , wherein the battery pack controller is connected to the reverse connection detector to receive the reverse connection detection signal transmitted from the reverse connection detector.