Voltage collection circuit and circuit control method
Embodiments of the present disclosure provide a voltage collection circuit and a circuit control method. The voltage collection circuit includes a battery monitoring chip, n switch units, and a controller. The battery monitoring chip is connected to a battery module including k battery cells, a battery cell CELL(i) is any one of the k battery cells. A switch unit Ji is connected in parallel to the battery cell CELL(i), a switch unit Js is connected in parallel to voltage collection channels Cs and C(s−1). The battery monitoring chip is configured to collect voltages of the k battery cells by using n+1 voltage collection channels. The controller is connected to the battery monitoring chip and control ends of the n switch units and configured to control working statuses of the n switch units according to the voltages collected by using the n+1 voltage collection channels.
1. A voltage collection apparatus, comprising
a battery monitoring chip,
a first quantity (n) of switch units consisting switch units J 1 , J 2 , . . . , through J n , and
a controller, wherein the first quantity (n) is a positive integer;
wherein the battery monitoring chip is connected to a battery module, wherein the battery module comprises a second quantity (k) of battery cells consisting of battery cells CELL( 1 ), CELL( 2 ), . . . , through CELL(k), the second quantity (k) is a positive integer less than or equal to the first quantity (n);
wherein switch units J 1 , J 2 , . . . , through J k are connected in parallel to the second quantity (k) of battery cells CELL( 1 ), CELL( 2 ), . . . , through CELL(k), respectively, wherein one and only one switch unit is connected it parallel to each of the battery cells;
wherein one and only one of the first quantity (n) of switch units is connected in parallel to each of n pairs of two adjacent voltage collection channels of n+1 voltage collection channels of the battery monitoring chip;
wherein the battery monitoring chip is configured to collect voltages of the second quantity (k) of battery cells by using at least some of the n+1 voltage collection channels; and
wherein the controller is connected to the battery monitoring chip and control ends of the first quantity (n) of switch units and configured to control working statuses of the first quantity (n) of switch units according to the voltages collected by using at least some of the n+1 voltage collection channels, and
wherein each of at least one first switch unit of the switch units comprises a diode and a relay, the relay is connected in parallel to the diode, a control end of the relay is connected to the controller, and a default working status of each first switch unit is that a conduction direction of the diode is opposite a discharge current direction of the battery cell.
2. The apparatus according to claim 1 , wherein
the controller is configured to: when a voltage collected by using a target voltage collection channel of the battery monitoring chip is less than or equal to a preset voltage threshold, control a relay of a first switch unit that corresponds to the target voltage collection channel to short-circuit a diode of the first switch unit that corresponds to the target voltage collection channel.
3. The apparatus according to claim 1 , wherein
each of at least one second switch unit of the switch unit comprises a diode and an optical Metal Oxide Semiconductor (MOS), the optical MOS is connected in parallel to the diode, a control end of the optical MOS is connected to the controller, and a default working status of each second switch unit is that a conduction direction of the diode is opposite a discharge current direction of the battery cell; and
the controller is configured to: when a voltage collected by a target voltage collection channel of the battery monitoring chip is less than or equal to a preset voltage threshold, control an optical MOS of a second switch unit that corresponds to the target voltage collection channel to short-circuit a diode of the second, switch unit that corresponds to the target voltage collection channel.
4. The apparatus according to claim 1 , wherein
each of at least one third switch unit of the switch units comprises an N-channel MOS, and a control end of the N-channel MOS is connected to the controller, and a default working status of each third switch unit is that a conduction direction of a body diode of the N-channel MOS is opposite a discharge current direction of the battery cell; and
the controller is configured to: when a voltage collected by a target voltage collection channel of the battery monitoring chip is less than or equal to a preset voltage threshold, control an N-channel MOS of a third switch unit that corresponds to the target voltage collection channel to short-circuit a body diode of the third switch unit that corresponds to the target voltage collection channel.
5. The apparatus according to claim 1 , wherein
each of at least one fourth switch unit of the switch units comprises a P-channel MOS, and a control end of the P-channel MOS is connected to the controller, and a default working status of each fourth switch unit is that a conduction direction of a body diode of the P-channel MOS is opposite a discharge current direction of the battery cell; and
the controller is configured to: when a voltage collected by a target voltage collection channel of the battery monitoring chip is less than or equal to a preset voltage threshold, control a P-channel MOS of a fourth switch unit that corresponds to the target voltage collection channel to short-circuit a body diode of the fourth switch unit that corresponds to the target voltage collection channel.
6. The apparatus according to of claim 1 , wherein
the controller and the first quantity (n) of switch units are connected directly or connected by using a conversion chip.
7. A circuit control method, wherein the method is applied to a voltage collection circuit, the voltage collection circuit comprises a battery monitoring chip, a first quantity (n) of switch units, and a controller, n being a positive integer, the method comprising:
obtaining, by the controller, voltages that are of a second quantity (k) battery cells comprised in a battery module and that are collected by the battery monitoring chip by using at least some of n+1 voltage collection channels, wherein the second quantity (k) is a positive integer less than or equal to the first quantity (n); and
controlling, by the controller, working statuses of the first quantity (n) of switch units according to the voltages collected by using at least some of the n+1 voltage collection channels,
wherein each of at least one first switch unit of the switch units comprises a diode and a relay, the relay is connected in parallel to the diode, a control end of the relay is connected to the controller, and a default working status of each first switch unit is that a conduction direction of the diode is opposite a discharge current direction of the battery cell.
8. The method according to claim 7 , wherein the controlling, by the controller, working statuses of the first quantity (n) of switch units according to the voltages collected by using at least some of the n+1 voltage collection channels comprises:
determining, by the controller, whether the voltages collected by using at least some of the n+1 voltage collection channels are less than or equal to a preset voltage threshold; and
when a target voltage collection channel where a voltage collected is less than or equal to the preset voltage threshold is determined, controlling, by the controller, a relay of a first switch unit that corresponds to the target voltage collection channel to short-circuit a diode of the first switch unit that corresponds to the target voltage collection channel.
9. The method according to claim 8 , further comprising:
when the target voltage collection channel where the voltage collected is less than or equal to the preset voltage threshold is determined, determining, by the controller, the second quantity (k) according to channel information of the target voltage collection channel.