Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, it will be appreciated by those of ordinary skill in the art that numerous technical details are set forth in order to provide a better understanding of the present application in various embodiments of the present invention. However, the technical solution claimed in the present application can be implemented without these technical details and various changes and modifications based on the following embodiments.
A first embodiment of the invention relates to a charging circuit applied to an electric vehicle for charging a battery pack of the electric vehicle; referring to fig. 1 and fig. 2, the charging circuit includes: at least one first relay 1, at least one second relay 2, at least one pre-check loop 3 and a controller 4. The controller 4 may be a battery management system of an electric vehicle.
The controller 4 is respectively connected to the control end of each first relay 1, the control end of each second relay 2 and each pre-detection loop 3, the pre-detection loop 3 corresponds to any one first relay 1, and the pre-detection loop 3 is connected in parallel to the corresponding first relay 1, that is, each first relay 1 can be connected in parallel to one or more pre-detection loops 3.
The first end of each first relay 1 is connected in the first end of group battery 5, the first end of each second relay 2 is connected in the second end of group battery 5, first relay 1 corresponds to arbitrary second relay 2, first relay 1 forms the charging port with corresponding second relay 2, an electric vehicle can include one or more charging port, first relay 1 and second relay 2 can be respectively for positive relay and the negative relay in the charging circuit, the relay of connecting in the anodal relay of group battery 5 is positive relay, the relay of connecting in the negative pole of group battery 5 is negative relay, two kinds of condition are included promptly: firstly, the first relay 1 is a positive relay, and the second relay 2 is a negative relay; second, the first relay 1 is a negative relay, and the second relay 2 is a positive relay. In this embodiment and the following embodiments, the first relay 1 is taken as a positive relay, and the second relay 2 is taken as a negative relay.
As shown in fig. 1, the electric vehicle includes two charging ports, K11, K21 are first relays 1, K12, K22 are second relays 2, the first relays 1K11 correspond to the second relays K12, and the first relays 1K21 correspond to the second relays K22. In the present embodiment and the following embodiments, the electric vehicle is described as including two charging ports. In addition, a plurality of first relays 1 may correspond to the same second relay 2, and as shown in fig. 3, two first relays 1K11, K21 correspond to one second relay 2K 12.
When electric vehicle's the port that charges is connected to external power source, for electric vehicle's group battery charges, external power source can be for filling electric pile, it can fill electric pile for single rifle to fill electric pile, the electric pile is filled to the double gun, the electric pile etc. is filled to the multi-gun, every rifle that charges includes positive relay and negative relay, the positive relay and the negative relay of each rifle that charges are connected with the electric capacity, as shown in fig. 1, K31, K41 are positive relay, K12, K22 is negative relay, electric capacity C1, C2 are the electric capacity that each rifle that charges corresponds. After the charging gun is inserted into the charging port of the electric vehicle, the positive relay and the negative relay of the charging gun are respectively connected to the positive relay and the negative relay of the charging port. The battery management system of the electric vehicle and the charging pile carry out charging parameter configuration, and after the charging parameter configuration is completed, the battery management system of the electric vehicle judges whether a positive relay and a negative relay of a charging port of the electric vehicle need to be closed or not according to a timing message, a charging capacity message and a self state sent by the charging pile. It should be noted that, in this embodiment and the following embodiments, the charging pile is taken as a dual-gun charging pile as an example for description; in addition, still include components and parts such as diode and electrolytic capacitor in filling electric pile, no longer give unnecessary details here.
When the charging gun is inserted into the charging port of the electric vehicle, that is, the first relay 1 is connected to the positive relays of the charging gun, that is, the positive relays K11, K21 are connected to the positive relays K31, K41 of the charging gun, respectively, and at this time, the negative relays K12, K22 are connected to the negative relays K32, K42 of the charging gun, respectively.
When the charging port is connected to an external power supply, namely a charging gun is inserted into the charging port, the first relay 1 is connected to a positive relay of the charging gun, and the second relay 2 is connected to a negative relay of the charging gun; that is, the first relays 1K11, K21 are connected to the positive relays K31, K41 of the charging gun, respectively, and the second relays 2K12, K22 are connected to the negative relays K32, K42 of the charging gun, respectively; taking the charging port including K11 and K12 as an example, the controller 4 controls to close the second relay 2K12 in the charging port, to turn on any one of the pre-detection circuits 3 connected in parallel to the first relay 1 in the charging port, and to collect the voltage between the second terminal of the first relay 1K11 in the charging port and the second terminal of the battery pack 5, which is referred to as a first voltage. Specifically, the controller 4 first controls the second relay 2K12 to close, and turns on the pre-detection circuit 3 connected in parallel to the first relay 1K11, so as to charge the capacitor C1 corresponding to the charging gun, and after the capacitor C1 is charged, the voltage between the second end of the first relay 1K11 and the second end of the battery pack 5 is collected and recorded as the first voltage. It should be noted that, in the present embodiment and the following embodiments, the first relay 1 is connected in parallel to one pre-detection loop 3 as an example, and when the first relay 1 is connected in parallel to a plurality of pre-detection loops 3, the pre-detection loop 3 can be selected to be closed according to the situation.
The controller 4 is further configured to determine whether a charging fault exists according to the first voltage and the voltage of the battery pack 5, that is, determine whether a charging gun connected to the charging port has a fault, and when it is determined that the charging gun has no charging fault, control the first relay 1K11 in the charging port to close and turn off the pre-detection loop 3 in a conducting state, so that the battery pack 5 can be charged by the charging gun; after the first relay 1K11 in the charging port is controlled to be closed, since the first relay 1K11 is usually a mechanical switch, a delay time, for example, 100ms, is set, and the pre-detection loop 3 in the on state is turned off.
It should be noted that, if the electric vehicle includes a plurality of charging ports, when the plurality of charging ports are connected to the charging guns, it is sequentially determined whether a charging fault exists in the plurality of charging guns, and when any charging gun has a fault, it is determined that the charging pile has a fault, and the charging pile cannot be used for charging the battery pack; if the battery pack of the electric vehicle is charged by a single gun, the charging gun connected with the electric vehicle is guaranteed to be free of fault, and the charging pile can be used for charging the battery pack of the electric vehicle.
Compared with the prior art, when the charging port is connected to an external power supply, the embodiment controls to close the second relay in the charging port, switches on any pre-detection loop of the first relay connected in parallel in the charging port, acquires the voltage between the second end of the first relay in the charging port and the second end of the battery pack, records the voltage as a first voltage, determines whether a charging fault exists according to the first voltage and the voltage of the battery pack, and controls to close the first relay in the charging port and switches off the pre-detection loop in a conducting state to charge the battery pack when the charging fault does not exist; therefore, whether a charging fault exists or not can be judged in advance before the battery pack is charged, when the charging fault does not exist, the first relay in the charging port is closed, the impact current of the first relay in the charging port when the first relay is closed can be effectively eliminated, and the occurrence of safety accidents such as adhesion of the first relay, charging port electrification and battery pack overcharge is reduced.
A second embodiment of the present invention relates to a charging circuit, and is substantially the same as the first embodiment, and is mainly different from the first embodiment in that: referring to fig. 1 to 3, specific ways of determining whether there is a charging failure according to the first voltage and the voltage of the battery pack are provided.
The controller 4 is configured to determine whether the first voltage is greater than a preset first voltage threshold, determine that a charging fault exists when it is determined that the first voltage is less than or equal to the first voltage threshold, and turn off the pre-detection circuit 3 in the on state. Specifically, the controller 4 determines whether a short-circuit fault exists on the charging pile side by determining whether the first voltage is greater than a preset first voltage threshold, and if the first voltage is greater than the preset first voltage threshold, it indicates that the short-circuit fault does not exist on the charging pile side; otherwise, it indicates that there is a short-circuit fault on the charging pile side, i.e. there is a charging fault, and turns off the pre-detection loop 3 in the on state.
The controller 4 is used for judging whether the charging pile is matched with the electric vehicle or not by judging whether the absolute value of the difference value of the first voltage and the voltage of the battery pack is smaller than or equal to a preset second voltage threshold or not when the first voltage is judged to be larger than the preset first voltage threshold; if the absolute value of the difference value between the first voltage and the voltage of the battery pack is smaller than or equal to a preset second voltage threshold, it is indicated that an overlarge impact current cannot be generated when the first relay 1 is closed, the charging pile is matched with the electric vehicle, then the first relay 1 in the charging port is controlled to be closed, the pre-detection loop 3 in a conducting state is turned off, and therefore the battery pack 5 can be charged through the charging gun; if the absolute value of the difference of the first voltage and the voltage of the battery pack is greater than the preset second voltage threshold, it is described that an excessive impact current is generated when the first relay 1 is closed, the problem of adhesion of the first relay 1 can be caused, the charging pile is not matched with the electric vehicle, namely, a charging fault exists, and the pre-detection loop 3 in a conducting state is turned off.
In one example, when determining that the first voltage is greater than the preset first voltage threshold, after a preset time period, the controller 4 determines whether an absolute value of a difference between the first voltage and the voltage of the battery pack is less than or equal to a preset second voltage threshold, where the preset time period is, for example, 1S; and the preset time is set so as to judge whether the absolute value of the difference value between the first voltage and the voltage of the battery pack is less than or equal to the preset second voltage threshold value when the first voltage is stable, so that the accuracy of the judgment result is ensured.
The present embodiment provides a specific implementation manner of determining whether there is a charging failure based on the first voltage and the voltage of the battery pack, as compared to the first embodiment.
A third embodiment of the present invention relates to a charging circuit, and is a refinement of the first embodiment, and is mainly characterized in that: referring to fig. 4, the pre-test circuit 3 includes a pre-test relay K1 and a resistor network 6; the resistor network 6 can be composed of a plurality of resistors connected in series, parallel or series-parallel.
The controller 4 is connected to the control end of the pre-test relay K1, and in fig. 4, an example will be described in which one end of the resistor network 6 is connected to the first end of the first relay 1 corresponding to the pre-test circuit 3, the other end of the resistor network 6 is connected to one end of the pre-test relay K1, and the other end of the pre-test relay K1 is connected to the second end of the first relay 1 corresponding to the pre-test circuit 3.
Taking the charging port including K11 and K12 as an example, when the charging port is connected to an external power source, that is, when a charging gun is inserted into the charging port, the controller 4 controls the second relay 2K12 in the charging port to be closed, controls the pre-test relay K1 in the pre-test circuit 3 connected in parallel to K11 to be closed, so as to conduct the pre-test circuit 3, and collects the voltage between the second end of the first relay 1K11 in the charging port and the second end of the battery pack 5, and records the voltage as a first voltage.
The controller 4 is further configured to determine whether a charging fault exists according to the first voltage and the voltage of the battery pack 5, that is, determine whether a charging gun connected to the charging port has a fault, and when it is determined that the charging gun has no charging fault, the controller 4 controls the first relay 1K11 in the charging port to be closed and turns off the pre-detection loop 3 in the on state by controlling the pre-detection relay K1 in the pre-detection loop 3 in the on state to be opened, so as to charge the battery pack 5; after the first relay 1K11 in the charging port is controlled to be closed, since the first relay 1K11 is generally a mechanical switch, a delay time, for example, 100ms, is set, and the pre-detection circuit 3 in the on state is turned off by controlling the pre-detection relay K1 in the pre-detection circuit 3 in the on state to be turned off.
In one example, when the number of the pre-detection loops 3 is multiple, the multiple pre-detection loops 3 are configured to share one resistor network 6, and referring to fig. 5, two pre-detection loops 3 share one resistor network 6.
In this embodiment, the charging circuit further includes: a plurality of first voltage sampling modules 7 and second voltage sampling modules 8; the first voltage sampling modules 7 correspond to the first relays 1 one by one, and the first voltage sampling modules 7 are connected between the second ends of the corresponding first relays 1 and the second end of the battery pack 5; the second voltage sampling module 8 is connected between two ends of the battery pack 5; the controller 4 is used for acquiring the voltage between the second end of the first relay 1 in the charging port and the second end of the battery pack 5 through the first voltage sampling module 7 corresponding to the first relay 1 in the charging port; the controller is used for acquiring the voltage of the battery pack 5 through the second voltage sampling module 8. The first voltage sampling module 7 and the second voltage sampling module 8 may be composed of a sampling resistor network and a switch circuit.
This embodiment provides a specific structure of the preliminary test circuit, compared to the first embodiment. In addition, the present embodiment can be further refined as compared with the second embodiment, and the same technical effects can be achieved.
A fourth embodiment of the present invention relates to a charging method applied to the controller 4 of the charging circuit of any one of the first to third embodiments, the controller 4 may be a battery management system of an electric vehicle; the following takes the charging circuit in the first embodiment as an example, please refer to fig. 1 and fig. 2.
Fig. 5 shows a specific flow of the method for detecting a load state according to the present embodiment.
Step 101, when the charging port is connected to an external power supply, controlling to close a second relay in the charging port, conducting any pre-detection loop of a first relay connected in parallel in the charging port, collecting voltage between a second end of the first relay in the charging port and a second end of the battery pack, and recording the voltage as first voltage.
Specifically, taking the example where the charging port includes K11 and K12, the controller 4 controls to close the second relay 2K12 in the charging port, to turn on any one of the pre-detection circuits 3 connected in parallel to the first relay 1 in the charging port, and to collect the voltage between the second terminal of the first relay 1K11 in the charging port and the second terminal of the battery pack 5, which is referred to as a first voltage. Specifically, the controller 4 first controls the second relay 2K12 to close, and turns on the pre-detection circuit 3 connected in parallel to the first relay 1K11, so as to charge the capacitor C1 corresponding to the charging gun, and after the capacitor C1 is charged, the voltage between the second end of the first relay 1K11 and the second end of the battery pack 5 is collected and recorded as the first voltage.
And step 102, determining whether a charging fault exists according to the first voltage and the voltage of the battery pack. If yes, directly ending; if not, go to step 103.
And 103, controlling a first relay in the charging port to be closed, and turning off the pre-detection loop in a conducting state.
Specifically, the controller 4 determines whether there is a charging failure, that is, determines whether there is a failure of the charging gun connected to the charging port, based on the first voltage and the voltage of the battery pack 5, and controls the first relay 1K11 in the charging port to close and turn off the pre-detection circuit 3 in the on state when it is determined that there is no charging failure of the charging gun, so that the battery pack 5 can be charged by the charging gun; after the first relay 1K11 in the charging port is controlled to be closed, since the first relay 1K11 is usually a mechanical switch, a delay time, for example, 100ms, is set, and the pre-detection loop 3 in the on state is turned off.
It should be noted that, if the electric vehicle includes a plurality of charging ports, when the plurality of charging ports are connected to the charging guns, it is sequentially determined whether a charging fault exists in the plurality of charging guns, and when any charging gun has a fault, it is determined that the charging pile has a fault, and the charging pile cannot be used for charging the battery pack; if the battery pack of the electric vehicle is charged by a single gun, the charging gun connected with the electric vehicle is guaranteed to be free of fault, and the charging pile can be used for charging the battery pack of the electric vehicle.
Since the first embodiment corresponds to the present embodiment, the present embodiment can be implemented in cooperation with the first embodiment. The related technical details mentioned in the first embodiment are still valid in this embodiment, and the technical effects that can be achieved in the first embodiment can also be achieved in this embodiment, and are not described herein again in order to reduce repetition. Accordingly, the related-art details mentioned in the present embodiment can also be applied to the first embodiment.
Compared with the prior art, when the charging port is connected to an external power supply, the embodiment controls to close the second relay in the charging port, switches on any pre-detection loop of the first relay connected in parallel in the charging port, acquires the voltage between the second end of the first relay in the charging port and the second end of the battery pack, records the voltage as a first voltage, determines whether a charging fault exists according to the first voltage and the voltage of the battery pack, and controls to close the first relay in the charging port and switches off the pre-detection loop in a conducting state to charge the battery pack when the charging fault does not exist; therefore, whether a charging fault exists or not can be judged in advance before the battery pack is charged, when the charging fault does not exist, the first relay in the charging port is closed, the impact current of the first relay in the charging port when the first relay is closed can be effectively eliminated, and the occurrence of safety accidents such as adhesion of the first relay, charging port electrification and battery pack overcharge is reduced.
A fifth embodiment of the present invention relates to a charging method, and is a refinement of the fourth embodiment, and is mainly characterized in that: specific ways of determining whether there is a charging failure based on the first voltage and the voltage of the battery pack are provided. In this embodiment, a charging circuit in a first embodiment is taken as an example for description, please refer to fig. 1 to 3.
Fig. 7 shows a specific flow of the method for detecting a load state according to the present embodiment.
Step 201, when the charging port is connected to the external power supply, controlling to close a second relay in the charging port, conducting any pre-detection loop of a first relay connected in parallel in the charging port, collecting the voltage between a second end of the first relay in the charging port and a second end of the battery pack, and recording the voltage as a first voltage.
Specifically, the method is substantially the same as step 101 in the fourth embodiment, and is not repeated here.
Step 202, comprising the following sub-steps:
in sub-step 2021, it is determined whether the first voltage is greater than a predetermined first voltage threshold. If yes, go to substep 2022; if not, go to substep 2023.
Specifically, the controller 4 determines whether the short-circuit fault exists on the charging pile side by determining whether the first voltage is greater than a preset first voltage threshold, and if the first voltage is greater than the preset first voltage threshold, it indicates that the short-circuit fault does not exist on the charging pile side, and the substep 2022 is performed; otherwise, it indicates that there is a short-circuit fault on the charging pile side, i.e., there is a charging fault, and the process goes to substep 2023.
In the sub-step 2022, it is determined whether the absolute value of the difference between the first voltage and the voltage of the battery pack is less than or equal to a preset second voltage threshold. If yes, go to step 203; if not, go to substep 2023.
Specifically, the controller 4 determines whether the charging pile is matched with the electric vehicle by determining whether the absolute value of the difference between the first voltage and the voltage of the battery pack is smaller than or equal to a preset second voltage threshold, if the absolute value of the difference between the first voltage and the voltage of the battery pack is smaller than or equal to the preset second voltage threshold, it indicates that an excessive impact current cannot be generated when the first relay 1 is closed, the charging pile is matched with the electric vehicle, and the step 203 is entered to turn off a pre-detection loop corresponding to the first relay and control the first relay connected to the charging gun to be closed; if the absolute value of the difference between the first voltage and the voltage of the battery pack is greater than the preset second voltage threshold, it is indicated that an excessive impact current is generated when the first relay 1 is closed, which may cause the adhesion of the first relay 1, and the charging pile is not matched with the electric vehicle, i.e., there is a charging fault, and the substep 2023 is performed.
In one example, when determining that the first voltage is greater than the preset first voltage threshold, after a preset time period, the controller 4 determines whether an absolute value of a difference between the first voltage and the voltage of the battery pack is less than or equal to a preset second voltage threshold, where the preset time period is, for example, 1S; and the preset time is set so as to judge whether the absolute value of the difference value between the first voltage and the voltage of the battery pack is less than or equal to the preset second voltage threshold value when the first voltage is stable, so that the accuracy of the judgment result is ensured.
Substep 2023, turns off the pre-detection loop in the on state.
And step 203, controlling a first relay in the charging port to be closed, and turning off the pre-detection loop in the conducting state.
Specifically, the controller 4 controls the first relay 1K11 in the charging port to close and turns off the pre-detection circuit 3 in the on state, so that the battery pack 5 can be charged by the charging gun.
Since the second embodiment corresponds to the present embodiment, the present embodiment can be implemented in cooperation with the second embodiment. The related technical details mentioned in the second embodiment are still valid in this embodiment, and the technical effects that can be achieved in the second embodiment can also be achieved in this embodiment, and are not described herein again in order to reduce repetition. Accordingly, the related-art details mentioned in the present embodiment can also be applied to the second embodiment.
The present embodiment provides a specific implementation manner of determining whether there is a charging failure based on the first voltage and the voltage of the battery pack, as compared with the fourth embodiment.
A sixth embodiment of the present invention relates to a charging method, and is a refinement of the fourth embodiment, and is mainly characterized in that: specific ways of turning off and on the pre-detection loop are provided. In the present embodiment, taking the charging circuit in the third embodiment as an example for explanation, please refer to fig. 3, the pre-detection circuit 3 includes a pre-detection relay K1 and a resistor network 6; the resistor network 6 can be composed of a plurality of resistors connected in series, parallel or series-parallel.
Fig. 8 shows a specific flow of the method for detecting a load state according to the present embodiment.
Step 301, when the charging port is connected to the external power supply, the pre-detection relay in any pre-detection loop of the first relay connected in parallel in the charging port is controlled to be closed, the pre-detection loop is conducted, and the voltage between the second end of the first relay in the charging port and the second end of the battery pack is collected and recorded as the first voltage.
Specifically, taking the example where the charging port includes K11 and K12, when the charging port is connected to an external power source, that is, when a charging gun is inserted into the charging port, the controller 4 controls to close the second relay 2K12 in the charging port, controls to close the pre-test relay K1 in the pre-test circuit 3 connected in parallel to K11, so as to turn on the pre-test circuit 3, and collects the voltage between the second terminal of the first relay 1K11 in the charging port and the second terminal of the battery pack 5, and records the voltage as the first voltage.
Step 302, determining whether a charging fault exists according to the first voltage and the voltage of the battery pack. If yes, directly ending; if not, go to step 303.
Specifically, the controller 4 determines whether there is a charging failure, that is, determines whether there is a failure of the charging gun connected to the charging port, based on the first voltage and the voltage of the battery pack 5; when it is determined that there is a charging failure, the battery pack 5 cannot be charged using the charging gun; otherwise, it indicates that there is no charging fault, and step 303 is entered.
And 303, controlling a first relay in the charging port to be closed, and switching off the on-state pre-detection loop by controlling a pre-detection relay in the on-state pre-detection loop to be switched off.
Specifically, the controller 4 controls the first relay 1K11 in the charging port to be closed, and turns off the on-state pre-detection circuit 3 by controlling the on-state pre-detection relay K1 in the on-state pre-detection circuit 3 to be opened, so as to charge the battery pack 5; after the first relay 1K11 in the charging port is controlled to be closed, since the first relay 1K11 is generally a mechanical switch, a delay time, for example, 100ms, is set, and the pre-detection circuit 3 in the on state is turned off by controlling the pre-detection relay K1 in the pre-detection circuit 3 in the on state to be turned off.
Since the third embodiment corresponds to the present embodiment, the present embodiment can be implemented in cooperation with the third embodiment. The related technical details mentioned in the third embodiment are still valid in this embodiment, and the technical effects that can be achieved in the third embodiment can also be achieved in this embodiment, and are not described herein again in order to reduce repetition. Accordingly, the related-art details mentioned in the present embodiment can also be applied to the third embodiment.
The present embodiment provides a specific way of turning off and turning on the pre-detection circuit, compared to the fourth embodiment. In addition, the present embodiment can be further refined as the fifth embodiment, and the same technical effects can be achieved.
A seventh embodiment of the invention relates to a vehicle that includes the charging circuit of any one of the first to third embodiments. Those skilled in the art will appreciate that the vehicle further includes a battery pack and the like, which will not be described in detail herein.
It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific examples for carrying out the invention, and that various changes in form and details may be made therein without departing from the spirit and scope of the invention in practice.