On-board power supply apparatus
An on-board power supply apparatus is for use in an on-board power supply system. The on-board power supply system includes a battery, an electric power path to which electric power based on the battery is supplied, and a capacitor that is connected to the electric power path. The on-board power supply apparatus includes a mechanical system main relay (first SMR), a parallel circuit, and a second relay. The system main relay (first SMR) is provided on the electric power path in a position on the battery side from the capacitor. The parallel circuit has a configuration in which a first relay and a resistance portion are connected in series, and is connected in parallel with the system main relay (first SMR). The second relay is provided in parallel with the resistance portion.
1 . An on-board power supply apparatus for use in an on-board power supply system including a battery, an electric power path to which electric power based on the battery is supplied, and a capacitor that is connected to the electric power path, the on-board power supply apparatus comprising:
a mechanical system main relay that is provided on the electric power path in a position on the battery side from the capacitor;
a parallel circuit that has a configuration in which a first relay and a resistance portion are connected in series, and that is provided in parallel with the system main relay; and
a second relay that is provided in parallel with the resistance portion.
2 . The on-board power supply apparatus according to claim 1 further comprising
a control unit that controls the system main relay, the first relay, and the second relay,
wherein the control unit:
if a starting condition for starting charging or discharging of the battery is satisfied, executes first control in which the system main relay and the second relay are controlled to be off and the first relay is controlled to be on;
if a first switching condition is satisfied during execution of the first control, executes second control in which the system main relay is controlled to be off and the first relay and the second relay are controlled to be on; and
if a second switching condition is satisfied during execution of the second control, executes third control in which the first relay and the second relay are controlled to be off and the system main relay is controlled to be on.
3 . The on-board power supply apparatus according to claim 2 , wherein the second relay is a semiconductor relay.
4 . The on-board power supply apparatus according to claim 2 , wherein the first switching condition is that a difference in electric potential between both ends of the system main relay or a value of a current flowing through the parallel circuit has equaled or fallen below a threshold.
5 . The on-board power supply apparatus according to claim 2 , wherein the first switching condition is that a first time amount has elapsed from the start of the first control.
6 . The on-board power supply apparatus according to claim 5 , wherein the second switching condition is that a second time amount that is shorter than the first time amount has elapsed from the start of the second control.
7 . The on-board power supply apparatus according to claim 2 , wherein the second switching condition is that the voltage of the capacitor has equaled or exceeded a threshold voltage.
8 . The on-board power supply apparatus according to claim 3 , wherein the first switching condition is that a difference in electric potential between both ends of the system main relay or a value of a current flowing through the parallel circuit has equaled or fallen below a threshold.
9 . The on-board power supply apparatus according to claim 3 , wherein the first switching condition is that a first time amount has elapsed from the start of the first control.
10 . The on-board power supply apparatus according to claim 3 , wherein the second switching condition is that the voltage of the capacitor has equaled or exceeded a threshold voltage.