Method for operating switching arrangement of energy storage system in vehicle

Abstract

A method for operating a switching arrangement of an energy storage system in a vehicle is disclosed. A computer system includes processing circuitry configured to: determine a measured current on each of a plurality of contactors of a switching arrangement of an energy storage system of a vehicle; determining a health level of each contactor; the sequence in which the battery packs are disconnected from the common traction voltage bus is controlled by opening closed contactors until all the battery packs are disconnected in response to a health level of unclosed contactors deviating from an average health level of all the contactors by more than a first predetermined value, the closed contactor having the lowest measured current is opened in response to the first predetermined value, and the closed contactor having the lowest health level is opened in response to the health level of the closed contactor having the lowest health level deviating from the average health level of all contactors by a value exceeding the first predetermined value.

Description

Technical Field

[0001] The present disclosure generally relates to operational management of a battery pack in an energy storage system of a vehicle. In a particular aspect, the present disclosure relates to a method for controlling a switch arrangement of an energy storage system of a vehicle. The present disclosure may be applicable to heavy vehicles such as trucks, buses, and construction equipment, among other vehicle types. Although the present disclosure may be described with respect to a particular vehicle, the present disclosure is not limited to any particular vehicle. Background Art

[0002] A vehicle typically includes an engine for propelling the vehicle. The engine may be an internal combustion engine powered by, for example, a liquid or gaseous fuel, or it may be an electric motor powered by electricity. Furthermore, there are hybrid solutions where the vehicle is propelled by both an internal combustion engine and an electric motor. Either way, an energy storage device is used to store the energy required to propel the vehicle. The energy storage device may also be used to power auxiliary loads in the vehicle.

[0003] For many vehicles, an energy storage device is included in an energy storage system, where the energy storage system is configured to power the motor used to propel the vehicle as well as any auxiliary loads. For example, for an electric vehicle, the energy storage device may be a battery or battery pack that is configured to operate the motor as well as the electric auxiliary equipment. The motor and / or the electric auxiliary equipment may generally be referred to as a load. Several batteries or several battery cells connected in series and / or in parallel may be grouped into a battery pack. The battery pack needs to be charged regularly and then electrically connected to an electrical energy source, for example via a plug connected directly to the grid or by an on-board charger. Such a charger may generally be referred to as a power source.

[0004] In many applications, several battery packs are included in an energy storage system (sometimes referred to as a multi-battery pack system) by being connected in parallel to a common traction voltage bus (or a common traction power bus). The load and / or power source are also connected to the common traction voltage bus. Thus, the power supplied can be adjusted based on the number of battery packs, and / or higher power requirements of the vehicle can be met. Typically, each battery pack is associated with a switch or contactor so that the battery pack can be connected and disconnected relative to the common traction voltage bus and the load and / or power source. However, each time the state of the contactor changes from closed to open, or vice versa, the contactor is subject to mechanical and electrical wear in the form of contactor wear.

[0005] The above-mentioned contactor wear may lead to contactor failure. In particular, premature contactor failure of a single contactor is undesirable because sometimes more than just the failed contactor needs to be replaced, which may be very troublesome. Summary of the invention

[0006] According to a first aspect of the present disclosure, there is provided a computer system comprising a processing circuit. The processing circuit is configured to: determine a measured current on each of a plurality of contactors of a switch arrangement of an energy storage system of a vehicle, the energy storage system comprising at least two battery packs arranged in parallel, and each contactor being configured to connect and disconnect the associated battery pack of the energy storage system from a common traction voltage bus by closing and opening, respectively; determine a health level of each contactor; control the order in which the battery packs are disconnected from the common traction voltage bus by opening the closed contactors in the following manner until all the battery packs are disconnected: in response to the health level of the non-closed contactor deviating from the average health level of all contactors by more than a first predetermined value, disconnect the closed contactor having the lowest measured current, and in response to the health level of the closed contactor having the lowest health level deviating from the average health level of all contactors by a value exceeding the first predetermined value and in response to the measured current of the non-closed contactor deviating from the average measured current of all contactors by more than a second predetermined value, disconnect the closed contactor having the lowest health level.

[0007] The first aspect of the present disclosure may seek to overcome problems associated with shortened contactor life and / or single contactor failure, because the control of the order in which the battery packs are disconnected from the common traction voltage bus, until all battery packs are disconnected, is performed in response to the measured current and the health level of the contactors. Therefore, the order in which the contactors are disconnected can be controlled in response to the health level of the contactors and the measured current, resulting in improved operation of which and when different closed contactors will be disconnected. Thereby, the risk of single contactor failure or at least premature single contactor failure is reduced. Therefore, the frequency of contactor maintenance or contactor replacement can be reduced. Therefore, the technical benefits of the first aspect of the present disclosure may include increasing the life of the contactors and / or reducing the risk of single contactor failure. That is, by using both the measured current and the health level of the contactors when determining the order in which the closed contactors are disconnected, an improved operation of disconnecting the battery packs from the common traction voltage bus is achieved until all battery packs are disconnected. It should be noted that the measured current on each of the plurality of contactors refers to the current on the corresponding contactor before or just before the contactor is disconnected. Hence, a plurality of contactors may refer to a plurality of closed contactors of a switching arrangement.

[0008] Optionally, in some examples, including at least one preferred example, the processing circuit is configured to determine the health level of each contactor as an overall health level of the contactor. Technical benefits may include improved determination of health levels and improved operation of which and when of different closed contactors will be opened, for example in terms of reducing the risk of a single contactor failure. The overall health level of a contactor may be referred to as the complete, full, absolute, or total health level of the contactor.

[0009] Optionally, in some examples, including at least one preferred example, the processing circuit is configured to determine the health level of each contactor on a scale of 0% to 100%. Technical benefits may include improved determination of health levels, and improved operation and time at which different closed contactors will be disconnected in terms of reducing the risk of single contactor failure. For example, a health level of 0% may correspond to a non-defective contactor. A non-defective contactor may also be referred to as an unworn, fresh, new or unused contactor. Accordingly, a health level of 100% may correspond to a contactor that is considered to require replacement or maintenance. Therefore, a contactor with a health level of 100% or a contactor that is considered to require replacement may still function, but is considered to have reached a predetermined threshold, i.e., the operation of the contactor is no longer reliable. Therefore, the contactor may still operate at a health level of 100%, and an increase in health level may still be considered, such as reaching a health level of 20% overdue (i.e., a corresponding health level of 120%). As an alternative, a contactor with a health level of 100% may correspond to a non-functional contactor. According to an alternative example, a 100% health level may correspond to a non-defective contactor. Accordingly, a health level of 0% may correspond to a contactor that is deemed to require replacement or maintenance. Thus, a contactor with a health level of 0% or deemed to require replacement may still be functional, but is deemed to have reached a predetermined threshold where the operation of the contactor is no longer reliable.

[0010] Optionally, in some examples, including at least one preferred example, the processing circuit is configured to determine the health level of each contactor according to the total operating time of each contactor, the total number of contactor disconnections, or a combination thereof. For example, a health level of 0% may correspond to a total operating time of 0 hours, or a total number of contactor disconnections of 0. Accordingly, a health level of 100% may correspond to a total operating time or a total number of contactor disconnections for which the contactor is deemed to need replacement, such as 1000 hours, or to, for example, 100,000 contactor disconnections or nominal contactor disconnections. As an alternative, the health level is set to the actual total operating time (ie, in hours) and / or the total number of contactor disconnections. However, the health level of the contactor may be calculated or estimated in other ways. Optionally, in some examples, including at least one preferred example, the processing circuit is configured to determine the health level of each contactor according to the total number of disconnections and the current when the disconnection occurs (ie, the current just before the contactor disconnects). For example, a contactor that opens at a higher current will cause a greater change in the health level than a contactor that opens at a lower current because a contactor that opens at a higher current will cause greater contactor wear.

[0011] Optionally, in some examples, including at least one preferred example, the processing circuit is configured to further control the order in which the battery packs are disconnected from the common traction voltage bus by opening the closed contactors in the following manner until all of the battery packs are disconnected: in response to a first closed contactor having the lowest health level and the health level of the first closed contactor deviating from the average health level of all contactors by a value exceeding the first predetermined value, and in response to a second closed contactor having the lowest measured current and the measured current of the second closed contactor deviating from the average measured current of all contactors by more than the second predetermined value, opening the first closed contactor or the second closed contactor. Technical benefits may include improving the operation of the order in which closed contactors are to be opened, for example, in terms of reducing the risk of a single contactor failure, for example, reducing the risk of a single contactor failure.

[0012] Optionally, in some examples, including at least one preferred example, the processing circuit is configured to disconnect the first closed contactor before the second closed contactor in response to the percentage rate at which the health level of the first closed contactor deviates from the average health level of all contactors being higher than the percentage rate at which the measured current of the second closed contactor deviates from the average measured current of all contactors. Technical benefits may include improving the operation of the order in which the closed contactors are to be disconnected, for example in terms of reducing the risk of a single contactor failure. Thus, for a situation in which the first closed contactor has the lowest health level and the health level of the first closed contactor deviates from the average health level of all contactors by a value exceeding the first predetermined value, and the second closed contactor has the lowest measured current and the measured current of the second closed contactor deviates from the average measured current of all contactors by more than the second predetermined value, a weighting between the health level and the measured current is provided.

[0013] Optionally, in some examples, including at least one preferred example, the processing circuit is configured to disconnect the second closed contactor before the first closed contactor in response to the measured current of the second closed contactor deviating from the average measured current of all contactors by a percentage rate that is higher than the percentage rate at which the health level of the first closed contactor deviates from the average health level of all contactors. Technical benefits may include improving the operation of the order in which the closed contactors are to be disconnected, for example in terms of reducing the risk of a single contactor failure. Thus, for a situation in which the first closed contactor has the lowest health level and the health level of the first closed contactor deviates from the average health level of all contactors by a value exceeding the first predetermined value, and the second closed contactor has the lowest measured current and the measured current of the second closed contactor deviates from the average measured current of all contactors by a value exceeding the second predetermined value, a weighting between the health level and the measured current is provided.

[0014] Optionally, in some examples, including at least one preferred example, the processing circuit is further configured to: receive measurement data from a plurality of sensors of the energy storage system, wherein the measurement data includes a measured current on each of a plurality of contactors. Technical benefits may include the use of reliable data and efficient data processing and communication. The plurality of sensors may, for example, include a current sensor and / or a voltage sensor for each of the contactors. Such a current sensor is typically arranged to directly measure the current on the corresponding contactor, or the current on the corresponding contactor may be indirectly measured via a voltage sensor. Therefore, the processing circuit may be configured to measure the current on each of the plurality of contactors. Therefore, the measured current may correspond to the previously mentioned determined measured current.

[0015] Optionally, in some examples, including at least one preferred example, the processing circuit is further configured to repeatedly determine the measured current on each of the plurality of contactors before each disconnection of the contactor. Technical benefits may include improved operation of the contactor over time.

[0016] In some examples, including at least one preferred example, preferably, the processing circuit is further configured to: identify at least two parallel-arranged battery packs connected to a common traction voltage bus of the energy storage system, and identify contactors associated with the parallel-arranged battery packs, wherein the sequence of controlling the closed contactors to open is performed for all identified parallel-arranged battery packs until no battery packs are connected to the common traction voltage bus. Technical benefits may include improved accuracy of controlled operation of contactors.

[0017] Optionally, in some examples, including at least one preferred example, the processing circuit is further configured to: after controlling the sequence of opening of the closed contactors, connect at least two of the battery packs to the common traction voltage bus by closing the associated contactors, and thereafter: alternately connect and disconnect the battery packs from the common traction voltage bus, wherein the sequence of controlling the closed contactors to open is performed for each disconnection. Technical benefits may include improved operation of contactors over time.

[0018] Optionally, in some examples, including in at least one preferred example, the processing circuit is configured to: determine an average health level of all closed contactors. Technical benefits may include improved determination of whether a closed contactor deviates from the average health level by a value exceeding a first predetermined value. The average health level may be determined, for example, by a ratio of the sum of the health levels of all closed contactors to the number of closed contactors for which the health level is determined.

[0019] Optionally, in some examples, including at least one preferred example, the first predetermined value is at least 1%, or at least 3%, or at least 5%, or at least 10%. The percentage of the first predetermined value may refer to an absolute percentage or percentage point corresponding to the health level of the contactor (i.e., for an embodiment in which the health level is determined on a scale of 0% to 100%), or may refer to a relative percentage corresponding to a percentage difference in an amount set for the health level. That is, a relative percentage may refer to a relative change or a change in the health level expressed as a percentage, i.e., an absolute change as a percentage of a unit value of the health level. Therefore, the processing circuit may be configured to disconnect the closed contactor with the lowest measured current in response to the health level of no closed contactor deviating from the average health level of all contactors by more than 1%, or 3%, or 5%, or 10%.

[0020] Optionally, in some examples, including in at least one preferred example, the processing circuit is configured to: determine an average measured current of all closed contactors. Technical benefits may include improved determination of whether a closed contactor deviates from the average measured current by a value exceeding a second predetermined value. The average measured current may be determined, for example, by a ratio of the sum of the measured currents of all closed contactors to the number of closed contactors for which the current is measured.

[0021] Optionally, in some examples, including at least one preferred example, the second predetermined value is at least 1%, or at least 3%, or at least 5%, or at least 10%. The percentage of the second predetermined value may refer to a relative percentage corresponding to a percentage difference in the amount measured for the current (i.e., amperes). That is, the relative percentage may refer to a relative change or a change in amperes expressed as a percentage, i.e., an absolute change in the measured current expressed as a percentage. Therefore, the processing circuit may be configured to: in response to the health level of the closed contactor with the lowest health level deviating from the average health level of all contactors by a value exceeding the first predetermined value (or exceeding 1%, or 3%, or 5%, or 10%), and in response to the current not measured deviating from the average measured current of all contactors by more than 1%, or 3%, or 5%, or 10%, disconnect the closed contactor with the lowest health level. As an alternative, the second predetermined value is expressed in amperes rather than a percentage. For example, the second predetermined value is at least 10 mA, or at least 100 mA, or at least 1000 mA, or at least 10000 mA.

[0022] Optionally, in some examples, including in at least one preferred example, the processing circuit is configured to further control the order in which the battery packs are disconnected from the common traction voltage bus by disconnecting the closed contactors in the following manner until all the battery packs are disconnected: in response to the health level of the non-closed contactor deviating from the average health level of all contactors by more than the first predetermined value, and in response to the measured current of the non-closed contactor deviating from the average measured current of all contactors by more than a second predetermined value, disconnecting any of the closed contactors. Technical benefits may include improving the operation of the order in which the closed contactors are to be disconnected, such as reducing the risk of a single contactor failure, in terms of, for example, reducing the risk of a single contactor failure. For example, in response to the health level of the non-closed contactor deviating from the average health level of all contactors by more than the first predetermined value, and the measured current of the non-closed contactor deviating from the average measured current of all contactors by more than the second predetermined value, disconnecting the next closed contactor may be alternated in time. The alternating disconnection may be performed in a "loop" process.

[0023] Optionally, in some examples, including in at least one preferred example, the processing circuit is configured to control the order in which the battery packs are disconnected from the common traction voltage bus by disconnecting the closed contactors in the following manner until all the battery packs are disconnected: in response to a health level of no closed contactor deviating from an average health level of all contactors by more than a first predetermined value, disconnecting the closed contactor with the lowest measured current; and in response to a health level of the closed contactor with the lowest health level deviating from the average health level of all contactors by a value exceeding the first predetermined value and in response to a measured current of no closed contactor deviating from the average measured current of all contactors by more than a second predetermined value, disconnecting the closed contactor with the lowest health level. contactor; and in response to a first closed contactor having the minimum health level and the health level of the first closed contactor deviating from the average health level of all contactors by a value exceeding a first predetermined value and in response to a second closed contactor having the minimum measured current and the measured current of the second closed contactor deviating from the average measured current of all contactors by more than the second predetermined value, disconnecting the first closed contactor or the second closed contactor; and in response to no closed contactor having a health level deviating from the average health level of all contactors by more than the first predetermined value and in response to no closed contactor having a measured current deviating from the average measured current of all contactors by more than the second predetermined value, disconnecting any one of the closed contactors.

[0024] Optionally, in some examples, including at least one preferred example, by declaring that the health level of no closed contactor deviates from the average health level of all contactors by more than the first predetermined value, the health levels of the closed contactors are substantially the same, or are regarded as having corresponding values. Optionally, in some examples, including at least one preferred example, by declaring that the health level of a closed contactor deviates from the average health level of all contactors by more than the first predetermined value, the health levels of the closed contactors are not the same, or are regarded as not having corresponding values.

[0025] Optionally, in some examples, including at least one preferred example, by stating that the measured current of the contactors that are not closed deviates from the average measured current by more than the second predetermined value, the measured currents of the closed contactors are substantially the same, or are considered to have corresponding values. Optionally, in some examples, including at least one preferred example, by stating that the measured current of the closed contactors deviates from the average measured current by more than the second predetermined value, the measured currents of the closed contactors are not the same, or are considered to have no corresponding values.

[0026] According to a second aspect of the present disclosure, a vehicle is provided, the vehicle comprising the computer system of the first aspect of the present disclosure. The second aspect of the present disclosure may seek to solve the same problems as described for the first aspect of the present disclosure. Therefore, the effects and features of the second aspect of the present disclosure are largely similar to those described above in conjunction with the first aspect of the present disclosure. The vehicle may, for example, include an energy storage system comprising a plurality of battery packs arranged in parallel as described above.

[0027] Optionally, in some examples, including at least one preferred example, the vehicle further comprises an energy storage system comprising at least two battery packs arranged in parallel and a switch arrangement comprising a plurality of contactors, each contactor being configured to connect and disconnect an associated battery pack of the energy storage system to a common traction voltage bus by closing and opening, respectively.

[0028] According to a third aspect of the present disclosure, a computer-implemented method is provided. The method includes: determining, by a processing circuit of a computer system, a measured current on each of a plurality of contactors of a switch arrangement of an energy storage system of a vehicle, the energy storage system comprising at least two battery packs arranged in parallel, and each contactor being configured to connect and disconnect the associated battery pack of the energy storage system to and from a common traction voltage bus by closing and opening, respectively; determining, by the processing circuit, a health level of each contactor; controlling, by the processing circuit, an order in which the battery packs are disconnected from the common traction voltage bus by disconnecting the closed contactors in the following manner until all the battery packs are disconnected: in response to a health level of a non-closed contactor deviating from an average health level of all contactors by more than a first predetermined value, disconnecting the contactor associated with the lowest measured current, and in response to a health level of the closed contactor having the lowest health level deviating from the average health level of all contactors by a value exceeding the first predetermined value and in response to a measured current of the non-closed contactor deviating from the average measured current of all contactors by more than a second predetermined value, disconnecting the closed contactor having the lowest health level.

[0029] The third aspect of the present disclosure may seek to solve the same problems as described for the first aspect of the present disclosure. Therefore, the effects and features of the third aspect of the present disclosure are largely similar to those described above in conjunction with the first aspect of the present disclosure, and are not repeated here. The processing circuit is, for example, the processing circuit of the first aspect of the present disclosure.

[0030] Optionally, in some examples, including in at least one preferred example, the method further comprises: determining, by the processing circuit, the health level of each contactor as an overall health level of the contactor.

[0031] Optionally, in some examples, including in at least one preferred example, the method further comprises: determining, by the processing circuit, the health level of each contactor on a scale of 0% to 100%.

[0032] Optionally, in some examples, including at least one preferred example, the method further includes: controlling the order in which the battery packs are disconnected from the common traction voltage bus by disconnecting the closed contactors in the following manner until all the battery packs are disconnected: in response to the first closed contactor having the lowest health level and the health level of the first closed contactor deviating from the average health level of all contactors by a value exceeding the first predetermined value, and in response to the second closed contactor having the lowest measured current and the measured current of the second closed contactor deviating from the average measured current of all contactors by more than the second predetermined value, disconnecting the first closed contactor or the second closed contactor by the processing circuit.

[0033] Optionally, in some examples, including at least one preferred example, the method further includes: disconnecting the first closed contactor before the second closed contactor by the processing circuit in response to the percentage rate at which the health level of the first closed contactor deviates from the average health level of all contactors being higher than the percentage rate at which the measured current of the second closed contactor deviates from the average measured current of all contactors.

[0034] Optionally, in some examples, including at least one preferred example, the method further includes: disconnecting the second closed contactor before the first closed contactor by the processing circuit in response to the percentage rate at which the measured current of the second closed contactor deviates from the average measured current of all contactors being higher than the percentage rate at which the health level of the first closed contactor deviates from the average health level of all contactors.

[0035] Optionally, in some examples, including in at least one preferred example, the method further comprises: repeatedly determining, by the processing circuit, the measured current on each of the plurality of contactors before each opening of the closed contactor.

[0036] Optionally, in some examples, including in at least one preferred example, the method includes performing any one of the actions that the processing circuit is configured to perform in the first aspect of the present disclosure. Therefore, the method may correspond to the configuration of the processing circuit of the first aspect of the present disclosure, and these examples are not repeated here.

[0037] According to a fourth aspect of the present disclosure, a computer program product is provided, the computer program product comprising program code, the program code being used to perform the method of the third aspect of the present disclosure when executed by the processing circuit. The processing circuit is, for example, the processing circuit of the first aspect of the present disclosure.

[0038] According to a fifth aspect of the present disclosure, there is provided a non-transitory computer-readable storage medium comprising instructions, which, when executed by the processing circuit, causes the processing circuit to perform the method of the third aspect of the present disclosure. The processing circuit is, for example, the processing circuit of the first aspect of the present disclosure.

[0039] The fourth to fifth aspects of the present disclosure can seek to solve the same problems as described for the first aspect of the present disclosure. Therefore, the effects and features of the fourth to fifth aspects of the present disclosure are largely similar to those described above in conjunction with the first aspect of the present disclosure.

[0040] It will be appreciated by those skilled in the art that the disclosed aspects, examples (including any preferred examples), and / or the accompanying claims may be appropriately combined with each other. Additional features and advantages are disclosed in the following description, claims, and drawings, and in part will be apparent to those skilled in the art or recognized by practicing the disclosure as described herein.

[0041] Also disclosed herein are computer systems, control units, code modules, computer-implemented methods, computer-readable media, and computer program products associated with the technical benefits discussed above. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is an exemplary partially schematic side view of an electric vehicle according to one example, the electric vehicle including an energy storage system having a plurality of battery packs arranged in parallel and a control unit.

[0043] Figure 2 is a schematic diagram of a switch arrangement of an energy storage system for a vehicle according to an example, the energy storage system having a plurality of battery packs arranged in parallel and a control unit.

[0044] Figure 3 is a flow chart illustrating acts or steps of a method according to one example.

[0045] Figure 4 is a schematic diagram of an exemplary computer system for implementing the examples disclosed herein, according to one example. DETAILED DESCRIPTION

[0046] The detailed description set forth below provides information and examples of the disclosed technology in sufficient detail to enable those skilled in the art to practice the disclosure.

[0047] The disclosed technology can solve the problems associated with the shortened contactor life of the energy storage system, or the failure of a single contactor. The contactor is configured to connect and disconnect the battery pack of the energy storage system with a common traction voltage bus by closing and opening, respectively. The disclosed technology solves the problem in particular by determining the measured current and health level of each contactor. The contactor may refer to a closed contactor of a switch arrangement. The measured current and health level of the contactor are used as input to determine the order of disconnection of the battery pack from the common traction voltage bus by opening the closed contactor by a processing circuit until all battery packs are disconnected. That is, in response to the measured current and health level of the contactor, the processing circuit determines which of the closed contactors is to be disconnected next until all battery packs are disconnected from the common traction voltage bus. Therefore, the order in which the contactors are disconnected can be controlled in response to the health level of the contactor and the measured current, resulting in improved operation (including which of the different closed contactors is to be disconnected next). Since a contactor that is disconnected at a relatively high (or higher) current causes a greater change in the health level than a contactor that is disconnected at a relatively low (or lower) current (i.e., the wear of the contactor is greater at a contactor that is disconnected at a relatively high current), controlling the disconnection sequence of the contactors in response to the measured current and health level can achieve improved operation of the contactors and / or maintenance of the contactors, and / or determination of contactor replacement.

[0048] Figure 1 A vehicle 1 is shown in the form of an exemplary heavy truck. The vehicle 1 is an electric vehicle, such as a fully electric vehicle or a hybrid vehicle, comprising at least one electric machine 10 (as a traction motor) powered by an energy storage system 30, wherein Figure 1 In the example of FIG. 1 , the energy storage system 30 includes three parallel battery packs 31 , 32 , 33 . The battery packs 31 , 32 , 33 are configured to provide power to at least one load (such as the motor 10 ). The vehicle 1 also includes an associated contactor (at Figure 2 ), the contactor is configured to connect and disconnect the battery packs 31, 32, 33 by closing and opening, respectively. The contactor may be included in the switch arrangement. In addition, the vehicle 1 includes a control unit 17 (including a processing circuit or included therein), which is arranged and configured to control at least part of the operation of the energy storage system 30, such as the opening and closing of the contactor. The vehicle 1 typically also includes other parts of the powertrain, such as a transmission, a drive shaft and wheels (not shown in detail). The motor 10 can act as an electric motor, consuming electricity provided by the battery packs 31, 32, 33, for example to provide propulsion power, and can act as a generator to generate electricity to charge the battery packs 31, 32, 33.

[0049] Figure 2 is a schematic diagram of a switch arrangement 115 and an energy storage system 130 having a plurality of parallel-connected battery packs 131 , 132 , 133 and a control unit 117 which comprises or is comprised in a processing circuit. Figure 2 The examples shown in Figure 1 A plurality of battery packs 131, 132, 133 are arranged in parallel to be connected to a common traction voltage bus 135 and to provide a plurality of loads 110a, 110b (for example, one of the loads 110b is a motor, for example, as Figure 1 The switch arrangement 115 is configured to connect and disconnect the battery packs 131, 132, 133 from a common traction voltage bus 135. In some examples, the common traction voltage bus 135 may be included in a junction box.

[0050] Each of the battery packs 131, 132, 133 generally includes a plurality of battery cells connected in series. The battery cells may be clustered into battery modules, wherein each battery pack 131, 132, 133 includes a plurality of battery modules connected in series. The energy storage system 130 may be referred to as a multi-battery pack system.

[0051] In more detail, the energy storage system 130 includes a first battery pack 131, a second battery pack 132, and a third battery pack 133, but it should be noted that any number of battery packs equal to or greater than two may be included in the energy storage system 130. The switch arrangement 115 includes an associated contactor 141, 142, 143 for each battery pack 131, 132, 133. Thus, the switch arrangement 115 includes a first contactor 141, which is configured to connect and disconnect the first battery pack 131 to the common traction voltage bus 135 by closing and opening, respectively, and includes a second contactor 142, which is configured to connect and disconnect the second battery pack 132 to the common traction voltage bus 135 by closing and opening, respectively, and includes a third contactor 143, which is configured to connect and disconnect the third battery pack 133 to the common traction voltage bus 135 by closing and opening, respectively. Therefore, an associated contactor (here, a first contactor 141, a second contactor 142, and a third contactor 143) is provided for each battery pack (here, a corresponding first battery pack 131, a second battery pack 132, and a third battery pack 133). By closing the corresponding first contactor 141, the second contactor 142, and the third contactor 143 (i.e., by connecting the first battery pack 131, the second battery pack 132, and the third battery pack 133 to the common traction voltage bus 135), all, some, or any one of the first battery pack 131, the second battery pack 132, and the third battery pack 133 can provide power to multiple loads 110a, 110b.

[0052] Any, some or all of the first battery pack 131, the second battery pack 132 and the third battery pack 133 can be disconnected from the common traction voltage bus 135 by opening the corresponding first contactor 141, the second contactor 142 and the third contactor 143. The control unit 117 is configured to control at least part of the operation of the switch arrangement 115, and thus control the opening and closing of the first contactor 141, the second contactor 142 and the third contactor 143. The switch arrangement 115 is configured via the control unit 117 to disconnect the first battery pack 131, the second battery pack 132 and the third battery pack 133 from the common traction voltage bus 135 through the first contactor 141, the second contactor 142 and the third contactor 143, respectively. The switch arrangement 115 may include additional contactors (e.g., pre-charging contactors, auxiliary contactors) for one or more of the battery packs 131, 132, 133.

[0053] In the first state (i.e., the fully connected state), each of the first contactor 141, the second contactor 142, and the third contactor 143 is closed, and each of the first battery pack 131, the second battery pack 132, and the third battery pack 133 is connected to the common traction voltage bus 135 to provide power to the plurality of loads 110a, 110b. In the second state (i.e., the disconnected state), one, two, or all three of the first contactor 141, the second contactor 142, and the third contactor 143 are opened to disconnect the corresponding first battery pack 131, the second battery pack 132, and the third battery pack 133 from the common traction voltage bus 135.

[0054] Figure 2 The energy storage system 130 includes a plurality of sensors configured to measure at least the current of each of the contactors 141, 142, 143. In more detail, the first sensor 151 is configured to measure the current of the first contactor 141, the second sensor 152 is configured to measure the current of the second contactor 142, and the third current sensor 153 is configured to measure the current of the third contactor 143. Each of the first sensor 151, the second sensor 152, and the third sensor 153 is configured to measure the current of the third contactor 143. Figure 2 Schematically shown in and can be a corresponding current sensor. Such current sensors are generally arranged to measure the current on the corresponding contactors 141, 142, 143. However, it should be mentioned that the sensor can be a voltage sensor or other type of sensor, which uses an applicable empirical law (such as, for example, Ohm's law) to determine the current based on the measured value of the voltage on the contactors 141, 142, 143. Therefore, since this determined current is based on the measured value (voltage, resistance, etc.), it can still be called a determined measured current. The control unit 117 is configured to receive measurement data or measured current from the sensors 131, 132, 133.

[0055] When the battery packs 131, 132, 133 are disconnected and the corresponding contactors 141, 142, 143 are disconnected, the contactors 141, 142, 143 are subject to contactor wear. A contactor disconnected at a relatively high (or higher) current causes greater wear than a contactor disconnected at a relatively low (or lower) current.

[0056] Each of the contactors 141, 142, 143 can be characterized by a corresponding health level or health status. The health level of each contactor 141, 142, 143 can be defined on a scale of 0% to at least 100%. For example, a health level of 0% can correspond to a non-defective contactor. A non-defective contactor can also be referred to as an unworn, fresh, new or unused contactor. Accordingly, a health level of 100% can correspond to a contactor that is considered to need replacement or maintenance. Therefore, a contactor with a health level of 100% or a contactor that is considered to need replacement may still function, but it is considered to have reached a predetermined threshold, that is, the operation of the contactor is no longer reliable. Therefore, the contactor can still operate at a health level of 100%, and an increase in the health level can still be considered, such as reaching a health level of 20% overdue (i.e., a corresponding health level of 120%). The health level of the contactors 141, 142, 143 can be determined according to their corresponding total operating time, the total number of disconnections of their corresponding contactors, or a combination thereof. For example, a health level of 0% may correspond to a total operating time of 0 hours, or a total number of contactor disconnections of 0. Accordingly, a health level of 100% may correspond to a total operating time at which the contactor is deemed to need replacement or a total number of contactor disconnections, for example, an operating time exceeding a predetermined operating time threshold, or a number of contactor disconnections exceeding a predetermined contactor disconnection threshold. The health level of each contactor 141, 142, 143 may alternatively be determined by the total number of disconnections as a function of the current at which the disconnection occurred (i.e., the current just before the contactor disconnected). For example, a contactor disconnected at a relatively high current may cause a greater change in the health level (e.g., a change in the health level of 0.1 percentage points) than a contactor disconnected at a relatively low current (e.g., a change in the health level of 0.01 percentage points). Therefore, the health level of the contactors 141, 142, 143 can be considered in an effective manner and change over time in an accurate manner.

[0057] The control unit 117 may be configured to determine a measured current across each contactor 141, 142, 143, or at least a closed contactor, using, for example, the first sensor 151, the second sensor 152, and the third sensor 153. Furthermore, the control unit 117 may be configured to determine a health level for each contactor 141, 142, 143, or at least each closed contactor, for example using the definition of contactor health levels previously described. Furthermore, the control unit 117 is typically configured to track the health levels of the contactors 141, 142, 143 over time and to adapt the health levels accordingly. Figure 2As shown, the switching device 115 may also include a memory 118 for storing such health level data. Accordingly, the control unit 117 may be configured to repeatedly determine the measured current on each contactor 141, 142, 143 before each opening of the contactor 141, 142, 143. The determined health level of each closed contactor generally corresponds to the overall health level of the contactor. A closed contactor is understood to be a contactor that currently provides an electrical connection (i.e., an electrical path) from the associated battery pack to the common traction voltage bus 135.

[0058] The control unit 117 may be configured to determine an average health level of all contactors 141, 142, 143 or at least all closed contactors. The average health level may be determined, for example, by the ratio of the sum of the health levels of all closed contactors to the number of closed contactors for which the health level is determined. Accordingly, the control unit 117 may be configured to determine an average measured current of all contactors 141, 142, 143 or at least all closed contactors. The average measured current may be determined, for example, by the ratio of the sum of the measured currents of all closed contactors to the number of closed contactors for which the current is measured.

[0059] The control unit 117 may control the order in which the closed contactors 141, 142, 143 are opened by the measured current and the determined health level of the contactors 141, 142, 143. That is, the control unit 117 may be configured to control the order in which the battery packs 131, 132, 133 are disconnected from the common traction voltage bus 135 by opening the closed contactors in response to the measured current and the health level of the contactors 141, 142, 143 until all battery packs are disconnected.

[0060] In more detail, the switch arrangement 115 is configured via the control unit 117 to disconnect the first battery pack 131, the second battery pack 132 and the third battery pack 133 from the common traction voltage bus 135 through the first contactor 141, the second contactor 142 and the third contactor 143, respectively, so that the first battery pack 131, the second battery pack 132 and the third battery pack 133 are disconnected in the order of first disconnecting one contactor (e.g., the first contactor 141), then disconnecting one contactor (e.g., the second contactor 142) and finally disconnecting one contactor (e.g., the third contactor 143), so that all the battery packs 131, 132, 133 are disconnected (i.e., no battery pack is connected to the common traction voltage bus 135 anymore). Assuming a fully connected state, the control unit 117 can be configured to control the order in which the battery packs 131, 132, 133 are disconnected from the common traction voltage bus 135 by disconnecting the closed contactors 141, 142, 143 in the following manner until all battery packs 131, 132, 133 are disconnected: in response to a health level of a non-closed contactor deviating from the average health level of all contactors 141, 142, 143 by more than a first predetermined value, disconnecting the closed contactor with the lowest measured current, and in response to the health level of the closed contactor with the lowest health level deviating from the average health level of all contactors 141, 142, 143 by a value that exceeds a first predetermined value, and in response to the measured current of the non-closed contactor deviating from the average measured current of all contactors 141, 142, 143 by more than a second predetermined value, disconnecting the closed contactor with the lowest health level. Therefore, the order in which the contactors 141, 142, 143 are disconnected can be controlled in response to the health level and the measured current of the contactors 141, 142, 143, resulting in improved operation of which of the closed contactors is to be disconnected next. As a result, the risk of a single contactor failure or at least a premature single contactor failure is reduced. For each contactor disconnection, the control unit 117 can again determine the health level and the measured current of each of the contactors 141, 142, 143, and then repeat the above-mentioned control of the disconnection of the contactors 141, 142, 143. Therefore, the health level of each of the contactors 141, 142, 143 can be determined and recorded. Thus, the energy storage system can enter a disconnected state from a fully connected state, wherein each of the first contactor 141, the second contactor 142, and the third contactor 143 is disconnected in a manner that disconnects each of the first battery pack 131, the second battery pack 132, and the third battery pack 133 from the common traction voltage bus 135, thereby terminating the provision of power to the loads 110a, 110b (e.g., in response to a shutdown signal of the loads 110a, 110b).However, the shut down of the loads 110a, 110b may also be performed in a fully connected state, such that the loads 110a, 110b do not request or extract any power from the battery packs 131, 132, 133, after which the connectors 141, 142, 143 are disconnected by a controlled procedure as described above.

[0061] In addition, the control unit 117 can also be configured to control the order in which the battery packs 131, 132, 133 are disconnected from the common traction voltage bus 135 by opening the closed contactors 141, 142, 143 in the following manner until all battery packs 131, 132, 133 are disconnected: in response to the first closed contactor (e.g., the first contactor 141) having the lowest health level and the health level of the first closed contactor 141 deviates from the average health level of all contactors 141, 142, 143 by a value exceeding a first predetermined value, and in response to the second closed contactor (e.g., the second contactor 142) having the lowest measured current and the measured current of the second closed contactor deviates from the average measured current of all contactors 141, 142, 143 by more than a second predetermined value, opening the first closed contactor 141 or the second closed contactor 142.

[0062] The control unit may implement a weighting between the health level and the measured current when deciding whether to open the first contactor 141 or the second contactor 142. For example, the control unit 117 may be configured to open the first closed contactor 141 before the second closed contactor 142 in response to the health level of the first closed contactor 141 deviating from the average health level of all contactors 141, 142, 143 by a higher percentage rate than the measured current of the second closed contactor 142 deviates from the average measured current of all contactors 141, 142, 143. Alternatively or in addition, the control unit 117 is configured to open the second closed contactor 142 before the first closed contactor 141 in response to the measured current of the second closed contactor 142 deviating from the average measured current of all contactors 141, 142, 143 by a higher percentage rate than the health level of the first closed contactor 141 deviates from the average health level of all contactors 141, 142, 143.

[0063] In addition, the control unit 117 may also be configured to control the order in which the battery packs 131, 132, 133 are disconnected from the common traction voltage bus 135 by disconnecting the closed contactors 141, 142, 143 in the following manner until all the battery packs 131, 132, 133 are disconnected: in response to the health level of the non-closed contactor deviating from the average health level of all contactors 141, 142, 143 by more than a first predetermined value, and in response to the measured current of the non-closed contactor deviating from the average measured current of all contactors 141, 142, 143 by more than a second predetermined value, disconnect any one of the closed contactors. For example, in response to the health level of the non-closed contactor deviating from the average health level of all contactors 141, 142, 143 by more than the first predetermined value, and the measured current of the non-closed contactor deviating from the average measured current of all contactors 141, 142, 143 by more than the second predetermined value, disconnecting the next closed contactor may be alternated in time. The alternating disconnection may be performed according to a "cyclic" process.

[0064] A summary example of the order in which the battery packs 131, 132, 133 are disconnected from the common traction voltage bus 135 until all battery packs 131, 132, 133 are disconnected is summarized in Table 1. Thus, based on the results of the measured current and health level of the contactors, Table 1 indicates the contactor to be disconnected next.

[0065] Table 1

[0066] In addition, the control unit 117 can also be configured to: after controlling the order of opening the closed contactors 141, 142, 143, connect at least two of the battery packs 131, 132, 133 to the common traction voltage bus 135 by closing the associated contactors 141, 142, 143, and thereafter: alternately connect and disconnect the battery packs 131, 132, 133 from the common traction voltage bus 135, wherein the order of opening the closed contactors 141, 142, 143 is performed for each disconnection.

[0067] As a supplement to controlling the order in which the contactors 141, 142, 143 are disconnected in response to the measured current and health level of the contactors as described above, the control unit 117 can predict maintenance or contactor replacement of the contactors 141, 142, 143 in response to the health level. For example, if the health level of a contactor reaches a predetermined threshold, for example, 100% of the health level, the control unit 117 can indicate (for example, to the driver of the vehicle) that such a contactor needs to be repaired or replaced. Therefore, the risk of a single contactor causing a contactor failure or premature contactor failure can be avoided or at least reduced. If a contactor is replaced, the old contactor can be replaced with a new contactor (for example, with a health level of 0%).

[0068] It should be mentioned that Figure 2 The switch arrangement 115 may also include a first pre-charging contactor arranged in parallel with the first contactor 141, wherein the first pre-charging contactor is arranged in series with the first pre-charging resistor, and includes a second pre-charging contactor arranged in parallel with the second contactor 142, wherein the second pre-charging contactor is arranged in series with the second pre-charging resistor, and includes a third pre-charging contactor arranged in parallel with the third contactor 143, wherein the third pre-charging contactor is arranged in series with the third pre-charging resistor. In addition, the first battery pack 131 may be connected in series with a first auxiliary contactor, which is arranged on a side of the first battery pack 131 opposite to the first contactor 141 (for example, the first contactor 141 is arranged at the positive side of the first battery pack 131, and the first auxiliary contactor is arranged at the negative side of the first battery pack 131). Accordingly, the second battery pack 132 can be connected in series with the second auxiliary contactor, which is arranged on the side of the second battery pack 132 opposite to the second contactor 142, and the third battery pack 133 can be connected in series with the third auxiliary contactor, which is arranged on the side of the third battery pack 133 opposite to the second contactor 143.

[0069] Figure 3 is a switch arrangement for controlling an energy storage system of a vehicle (such as Figure 2 Flow chart of a computer-implemented method of a switch arrangement 115 and an energy storage system 130).

[0070] In a first action or step S10, a measured current is determined by a processing circuit of a computer system on each of a plurality of contactors of a switch arrangement. The energy storage system comprises at least two battery packs arranged in parallel, and each contactor is configured to connect and disconnect an associated battery pack of the energy storage system from a common traction voltage bus by closing and opening, respectively. The plurality of contactors may be a plurality of closed contactors of the switch arrangement. The first action or step S10 may comprise receiving, by a processor circuit, measurement data from a plurality of sensors of the energy storage system, wherein the measurement data comprises a measured current on each of the plurality of contactors.

[0071] In a second optional action or step S20, the processor circuit determines an average measured current of all contactors. The average measured current may be determined, for example, by the ratio of the sum of the measured currents of all closed contactors to the number of closed contactors for which the currents were measured.

[0072] In a third action or step S30, the processor circuit determines the health level of each contactor. The health level of a particular contactor may be, for example, the overall health level of such contactors. For example, the health level of each contactor may be determined by the processor circuit on a scale of 0% to 100%.

[0073] In a fourth optional action or step S40, the processor circuit determines an average health level of all contactors. The average health level may be determined, for example, by the ratio of the sum of the health levels of all closed contactors to the number of closed contactors.

[0074] In a fifth action or step S50, the order in which the battery packs are disconnected from the common traction voltage bus is controlled by opening the closed contactors in the following manner until all battery packs are disconnected: in a first sub-action or sub-step S52, in response to the health level of the non-closed contactors deviating from the average health level of all contactors by more than a first predetermined value, the contactor associated with the lowest measured current is opened by the processing circuit; in a second sub-action or sub-step S54, in response to the health level of the closed contactor with the lowest health level deviating from the average health level of all contactors by a value exceeding the first predetermined value, and in response to the measured current of the non-closed contactors deviating from the average measured current of all contactors by more than a second predetermined value, the closed contactor with the lowest health level is opened by the processing circuit. That is, in response to the measured current and health level of the contactors, the closed contactors are opened in sequence by the processing circuit until all battery packs are disconnected from the common traction voltage bus. Therefore, the order in which the contactors are opened can be controlled in response to the health level of the contactors and the measured current, resulting in improved operation (including which of the closed contactors is to be opened next). Typically, the first step S10 and possibly the third step S30 and the second step S20 and / or the fourth step S40 are repeated each time before the closed contactor is opened.

[0075] In optional sub-actions or sub-steps S56 to S50, in response to the first closed contactor having the lowest health level and the health level of the first closed contactor deviating from the average health level of all contactors by more than a first predetermined value, and in response to the second closed contactor having the lowest measured current and the measured current of the second closed contactor deviating from the average measured current of all contactors by more than a second predetermined value, the first closed contactor or the second closed contactor is disconnected by the processing circuit. When deciding whether to disconnect the first contactor or the second contactor, the processing circuit can implement weighting between the health level and the measured current. For example, in sub-action or sub-step S56a, in response to the percentage rate at which the health level of the first closed contactor deviates from the average health level of all contactors being higher than the percentage rate at which the measured current of the second closed contactor deviates from the average measured current of all contactors, the first closed contactor is disconnected before the second closed contactor by the processing circuit. Alternatively, in sub-action or sub-step S56b, the second closed contactor is opened before the first closed contactor by the processing circuit in response to the percentage rate at which the measured current of the second closed contactor deviates from the average measured current of all contactors being higher than the percentage rate at which the health level of the first closed contactor deviates from the average health level of all contactors.

[0076] In optional sub-actions or sub-steps S58 to S60, in response to the health level of the non-closed contactor deviating from the average health level of all contactors by more than a first predetermined value, and in response to the measured current of the non-closed contactor deviating from the average measured current of all contactors by more than a second predetermined value, any one of the closed contactors is opened. For example, the opening of the next closed contactor may alternate in time according to a "loop" process.

[0077] The method may include a sixth action or step S60 of closing the contactors by the processing circuit to connect the battery pack to the common traction voltage bus. Furthermore, as previously described, the battery pack may be alternately connected and disconnected from the common traction voltage bus, wherein the action or step of disconnecting includes controlling the order in which the contactors are opened, as described above. Thus, the order in which the battery packs are disconnected, controlled by the switch arrangement, may be applied over time and during operation of the energy storage system.

[0078] In an optional seventh action or step S70, in response to the health level of the contactor, contactor maintenance or contactor replacement is predicted by the processing circuit. For example, the contactor maintenance information can be sent to a display, such as a vehicle monitor, for example. Therefore, the driver of the vehicle can utilize the contactor maintenance information and decide to perform maintenance on the switch arrangement.

[0079] In a first optional pre-action or pre-step S5 of the first action or step S10, the processing circuit identifies a plurality of parallel arranged battery packs connected to a common traction voltage bus of the energy storage system. In a second optional pre-action or step S7 of the first action or step S10, the processing circuit identifies closed contactors associated with the plurality of parallel arranged battery packs. The closed contactors so identified may then be affected by the previously described actions or steps S10, optional S20, S30, optional S40 and S50. Thus, a fifth action or step S50 may be performed for all identified closed contactors.

[0080] It should be noted that not all battery packs of the energy storage system need to be connected every time the energy storage system is to power a load connected to the common traction voltage bus. For example, if the load requires only two of the three battery packs to be powered, the third battery pack and therefore the contactors associated with the third battery pack can be idle in such cases. During disconnection of the connected battery packs, the disconnection sequence controlled by the switch arrangement will be applied to the battery packs connected to the common traction voltage bus for powering the loads, i.e., in this case, the first battery pack and the second battery pack.

[0081] Figure 1 The control unit 17 or Figure 2 The control unit 117 may be configured to perform a reference Figure 3 Therefore and with reference to Figure 1 The processing circuit may comprise the control unit 17 of the vehicle 1 or be included in said control unit, or refer to Figure 2 , the processing circuit may include the control unit 117 or be included in the control unit. Figure 3 The described method may be implemented in a computer program product comprising a computer program product for executing a reference when executed by a processing circuit. Figure 3 Alternatively, as referenced Figure 3 The described method may be implemented in a non-transitory computer-readable storage medium comprising instructions that, when executed by a processing circuit, cause the processing circuit to perform the Figure 3 Therefore, the control unit 17 may include a method for causing the energy storage system 30 to be operated according to the reference Figure 3 Instructions describing at least some actions or steps to operate. In addition, Figure 2 The control unit 117 may include a device for causing the switch arrangement 115 to be configured according to a reference Figure 3 Instructions that describe at least some actions or steps to operate. Figure 1 The control unit 17 of the vehicle 1 or Figure 2 The control unit 117 of the switch arrangement 115 may constitute or be included in a control system comprising a control system configured to perform as described in reference Figure 3 One or more control units of the method described. Now referring to Figure 4 Such a control system 1000 is described.

[0082] Figure 4 is used to implement the examples disclosed herein (e.g., as referenced Figure 3Schematic diagram of a computer system 1000 for executing instructions from a computer-readable medium to perform these and / or any functions or processes described herein. The computer system 1000 may be connected (e.g., networked) to other machines in a LAN, an intranet, an extranet, or the Internet. Although only a single device is shown, the computer system 1000 may include any collection of devices that execute an instruction set (or multiple instruction sets) individually or jointly to perform any one or more of the methods discussed herein. Therefore, any reference to a computer system, a computing system, a computer device, a computing device, a control system, a control unit, an electronic control unit (ECU), a processor device, a processing circuit, etc. in the present disclosure and / or claims includes a reference to one or more such devices to execute an instruction set (or multiple instruction sets) individually or jointly to perform any one or more of the methods discussed herein. For example, the control system may include a single control unit or multiple control units connected to each other or otherwise communicatively coupled so that any executed functions can be distributed between the control units as needed. In addition, such devices may communicate with each other or other devices through various system architectures (such as directly or via a controller area network (CAN) bus, etc.).

[0083] The computer system 1000 may include at least one computing device or electronic device that can include firmware, hardware and / or execute software instructions to implement the functionality described herein. The computer system 1000 may include a processing circuit 1002 (e.g., a processing circuit that includes one or more processor devices or control units), a memory 1004, and a system bus 1006. The computer system 1000 may include at least one computing device with a processing circuit 1002. The system bus 1006 provides an interface for system components (including, but not limited to, the memory 1004 and the processing circuit 1002). The processing circuit 1002 may include any number of hardware components for performing data or signal processing or for executing computer code stored in the memory 1004. The processing circuit 1002 may include, for example, a general purpose processor, a special purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a circuit containing a processing component, a group of distributed processing components, a group of distributed computers configured for processing, or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The processing circuit 1002 may also include computer executable code that controls the operation of the programmable device.

[0084] The system bus 1006 may be any of several types of bus structures, which may be further interconnected to a memory bus (with or without a memory controller), a peripheral bus, and / or a local bus using any of a variety of bus architectures. The memory 1004 may be one or more devices for storing data and / or computer code to accomplish or facilitate the methods described herein. The memory 1004 may include a database component, an object code component, a script component, or any type of information structure for supporting the various activities herein. Any distributed or local memory device may be utilized with the systems and methods of the present specification. The memory 1004 may be communicatively connected to the processing circuit 1002 (e.g., via a circuit or any other wired, wireless, or network connection) and may include computer code for performing one or more processes described herein. The memory 1004 may include nonvolatile memory 1008 (e.g., read-only memory (ROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), etc.) and volatile memory 1010 (e.g., random access memory (RAM)), or any other medium that can be used to carry or store desired program code in the form of machine-executable instructions or data structures and that can be accessed by a computer or other machine having the processing circuit 1002. A basic input / output system (BIOS) 1012 may be stored in the nonvolatile memory 1008 and may include the basic routines that help to transfer information between elements within the computer system 1000.

[0085] The computer system 1000 may also include or be coupled to non-transitory computer-readable storage media such as storage device 1014, which may include, for example, an internal or external hard disk drive (HDD) (e.g., Enhanced Integrated Drive Electronics (EIDE) or Serial Advanced Technology Attachment (SATA)), a HDD for storage (e.g., EIDE or SATA), flash memory, etc. The storage device 1014 and other drives associated with computer-readable and computer-usable media may provide non-volatile storage of data, data structures, computer-executable instructions, etc.

[0086] The hard-coded or soft-coded computer code may be provided in the form of one or more modules. The modules may be implemented as software and / or hard-coded in the circuit to implement the functionality described herein in whole or in part. These modules may be stored in a storage device 1014 and / or a volatile memory 1010 that may include an operating system 1016 and / or one or more program modules 1018. All or part of the examples disclosed herein may be implemented as a computer program 1020 stored on a temporary or non-temporary computer-available or computer-readable storage medium (e.g., a single medium or multiple media) such as a storage device 1014, which includes complex programming instructions (e.g., complex computer-readable program code) that cause the processing circuit 1002 to perform the actions described herein. Therefore, the computer-readable program code of the computer program 1020 may include software instructions for implementing the functions of the examples described herein when executed by the processing circuit 1002. In some examples, storage device 1014 may be a computer program product (e.g., a readable storage medium) having computer program 1020 stored thereon, wherein at least a portion of computer program 1020 may be loadable (e.g., loaded into a processor) for implementing the functionality of the examples described herein when executed by processing circuit 1002. Processing circuit 1002 may serve as a controller or control system of computer system 1000 for implementing the functionality described herein.

[0087] The computer system 1000 may include an input device interface 1022 configured to receive input and selections to be transmitted to the computer system 1000 when executing instructions, such as from a keyboard, mouse, touch-sensitive surface, etc. Such input devices may be connected to the processing circuit 1002 through an input device interface 1022 coupled to the system bus 1006, but may be connected through other interfaces such as a parallel port, an Institute of Electrical and Electronics Engineers (IEEE) 1394 serial port, a universal serial bus (USB) port, an IR interface, etc. The computer system 1000 may include an output device interface 1024 configured to forward output to a display, a video display unit (e.g., a liquid crystal display (LCD) or a cathode ray tube (CRT)). The computer system 1000 may include a communication interface 1026 suitable for communicating with a network as appropriate or as needed.

[0088] The actions described in any of the exemplary aspects of this article are described to provide examples and discussions. These actions can be performed by hardware components, can be embodied in machine executable instructions so that a processor performs these actions, or can be performed by a combination of hardware and software. Although a specific order of method actions can be shown or described, the order of actions can be different. In addition, two or more actions can be performed simultaneously or partially simultaneously.

[0089] Example 1. A computer system comprising a processing circuit configured to: determine a measured current on each of a plurality of contactors of a switch arrangement of an energy storage system of a vehicle, the energy storage system comprising at least two battery packs arranged in parallel and each contactor configured to connect and disconnect an associated battery pack of the energy storage system to and from a common traction voltage bus by closing and opening, respectively; determine a health level of each contactor; control an order in which the battery packs are disconnected from the common traction voltage bus by opening closed contactors in the following manner until all of the battery packs are disconnected: - in response to a health level of an unclosed contactor deviating from an average health level of all contactors by more than a first predetermined value, opening the closed contactor having the lowest measured current, and - in response to a health level of the closed contactor having the lowest health level deviating from the average health level of all contactors by a value that exceeds the first predetermined value and in response to a measured current of an unclosed contactor deviating from the average measured current of all contactors by more than a second predetermined value, opening the closed contactor having the lowest health level.

[0090] Example 2. The computer system of Example 1, wherein the processing circuit is configured to determine the health level of each contactor as an overall health level of the contactor.

[0091] Example 3. The computer system of any of Examples 1 to 2, wherein the processing circuit is configured to determine the health level of each contactor on a scale of 0% to 100%.

[0092] Example 4. A computer system according to any one of Examples 1 to 3, wherein the processing circuit is configured to further control the order in which the battery packs are disconnected from the common traction voltage bus by opening the closed contactors in the following manner until all of the battery packs are disconnected: - in response to a first closed contactor having the lowest health level and the health level of the first closed contactor deviating from the average health level of all contactors by a value exceeding the first predetermined value, and in response to a second closed contactor having the lowest measured current and the measured current of the second closed contactor deviating from the average measured current of all contactors by more than the second predetermined value, opening the first closed contactor or the second closed contactor.

[0093] Example 5. A computer system according to Example 4, wherein the processing circuit is configured to open the first closed contactor before the second closed contactor in response to the percentage rate at which the health level of the first closed contactor deviates from the average health level of all contactors being higher than the percentage rate at which the measured current of the second closed contactor deviates from the average measured current of all contactors.

[0094] Example 6. A computer system according to any one of Examples 4 to 5, wherein the processing circuit is configured to open the second closed contactor before the first closed contactor in response to the percentage rate at which the measured current of the second closed contactor deviates from the average measured current of all contactors being higher than the percentage rate at which the health level of the first closed contactor deviates from the average health level of all contactors.

[0095] Example 7. A computer system according to any one of Examples 1 to 6, wherein the processing circuit is further configured to: receive measurement data from a plurality of sensors of the energy storage system, wherein the measurement data includes a measured current on each of a plurality of contactors.

[0096] Example 8. The computer system of any one of Examples 1 to 7, wherein the processing circuit is further configured to repeatedly determine the measured current across each of the plurality of contactors before each opening of the contactor.

[0097] Example 9. A computer system according to any one of Examples 1 to 8, wherein the processing circuit is further configured to: after controlling the order in which the closed contactors are opened, connect at least two of the battery packs to the common traction voltage bus by closing the associated contactors, and thereafter: alternately connect and disconnect the battery packs from the common traction voltage bus, wherein the order in which the closed contactors are controlled to open is performed for each disconnection.

[0098] Example 10. A vehicle comprising a computer system according to any one of Examples 1 to 9.

[0099] Example 11. The vehicle according to Example 10, further comprising: an energy storage system comprising at least two battery packs arranged in parallel and a switch arrangement comprising a plurality of contactors, each contactor being configured to connect and disconnect an associated battery pack of the energy storage system to a common traction voltage bus by closing and opening, respectively.

[0100] Example 12. A computer-implemented method comprising: determining, by a processing circuit of a computer system, a measured current on each of a plurality of contactors of a switch arrangement of an energy storage system of a vehicle, the energy storage system comprising at least two battery packs arranged in parallel and each contactor being configured to connect and disconnect an associated battery pack of the energy storage system to and from a common traction voltage bus by closing and opening, respectively; determining, by the processing circuit, a health level of each contactor; controlling, by the processing circuit, an order in which the battery packs are disconnected from the common traction voltage bus by opening closed contactors in the following manner until all of the battery packs are disconnected: - in response to a health level of an unclosed contactor deviating from an average health level of all contactors by more than a first predetermined value, opening the contactor associated with the lowest measured current, and - in response to a health level of the closed contactor having the lowest health level deviating from the average health level of all contactors by a value exceeding the first predetermined value and in response to a measured current of the unclosed contactor deviating from the average measured current of all contactors by more than a second predetermined value, opening the closed contactor having the lowest health level.

[0101] Example 13. The method of Example 12, further comprising determining, by the processing circuit, the health level of each contactor as an overall health level of the contactors.

[0102] Example 14. The method of any of Examples 12 to 13, further comprising determining, by the processing circuit, the health level of each contactor on a scale of 0% to 100%.

[0103] Example 15. A method according to any one of Examples 12 to 14, further comprising: controlling the order in which the battery packs are disconnected from the common traction voltage bus by disconnecting the closed contactors in the following manner until all of the battery packs are disconnected: - in response to a first closed contactor having the lowest health level and the health level of the first closed contactor deviating from the average health level of all contactors by a value exceeding the first predetermined value, and in response to a second closed contactor having the lowest measured current and the measured current of the second closed contactor deviating from the average measured current of all contactors by more than the second predetermined value, disconnecting the first closed contactor or the second closed contactor by the processing circuit.

[0104] Example 16. The method according to Example 15 further includes: disconnecting the first closed contactor before the second closed contactor by the processing circuit in response to the percentage rate at which the health level of the first closed contactor deviates from the average health level of all contactors being higher than the percentage rate at which the measured current of the second closed contactor deviates from the average measured current of all contactors.

[0105] Example 17. A method according to any one of Examples 15 to 16, further comprising: disconnecting the second closed contactor before the first closed contactor by the processing circuit in response to the percentage rate at which the measured current of the second closed contactor deviates from the average measured current of all contactors being higher than the percentage rate at which the health level of the first closed contactor deviates from the average health level of all contactors.

[0106] Example 18. The method of any one of Examples 12 to 17, further comprising: repeatedly determining, by the processing circuit, the measured current across each of the plurality of contactors before each opening of the closed contactor.

[0107] Example 19. A computer program product comprising program code for performing the method according to any one of Examples 12 to 18 when executed by the processing circuit.

[0108] Example 20. A non-transitory computer-readable storage medium comprising instructions that, when executed by the processing circuit, cause the processing circuit to perform the method according to any one of Examples 12 to 18.

[0109] The terms used herein are only for the purpose of describing specific aspects and are not intended to limit the present disclosure. As used herein, unless the context clearly indicates otherwise, the singular forms "a" and "the" are intended to include the plural forms as well. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. It should also be understood that the terms "include" and / or "comprising" when used herein indicate the presence of stated features, integers, actions, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, actions, steps, operations, elements, components and / or their groups.

[0110] It should be understood that although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, without departing from the scope of the present disclosure, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0111] Relative terms such as "below" or "above" or "upper" or "lower" or "horizontal" or "vertical" may be used herein to describe the relationship of one element to another element, as shown in the figures. It should be understood that these terms and those discussed above are intended to cover different device orientations in addition to the orientations depicted in the figures. It should be understood that when an element is referred to as being "connected" or "coupled" to another element, the element may be directly connected or directly coupled to the other element, or there may be intervening elements. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements.

[0112] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those commonly understood by those skilled in the art to which the present disclosure belongs. It should also be understood that, unless otherwise clearly defined herein, the terms used herein should be interpreted as meanings consistent with their meanings in the context of this specification and the relevant art, and should not be interpreted in an idealized or overly formal sense.

[0113] It should be understood that the present disclosure is not limited to the aspects described above and shown in the accompanying drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the present disclosure and the appended claims. In the drawings and description, various aspects have been disclosed for illustrative purposes only and not for limiting purposes, and the scope of the disclosure is set forth in the appended claims.

Claims

1. A computer system comprising a processing circuit, wherein the processing circuit is configured to: - determining a measured current across each of a plurality of contactors of a switching arrangement of an energy storage system of a vehicle, the energy storage system comprising at least two battery packs arranged in parallel and each contactor being configured to connect and disconnect, by closing and opening, respectively, an associated battery pack of the energy storage system from a common traction voltage bus; - Determine the health level of each contactor; - Controlling the order in which the battery packs are disconnected from the common traction voltage bus by opening the closed contactors in the following manner until all the battery packs are disconnected: - in response to the health level of no closed contactor deviating from the average health level of all contactors by more than a first predetermined value, opening said closed contactor having the lowest measured current, and - in response to the health level of the closed contactor with the lowest health level deviating from the average health level of all contactors by a value exceeding the first predetermined value and in response to the measured current of the non-closed contactors deviating from the average measured current of all contactors by more than a second predetermined value, opening the closed contactor with the lowest health level. 2 . The computer system of claim 1 , wherein the processing circuit is further configured to determine the health level of each contactor as an overall health level of the contactor.

3. The computer system of any one of claims 1 to 2, wherein the processing circuit is further configured to determine the health level of each contactor on a scale of 0% to 100%.

4. The computer system of any one of claims 1 to 3, wherein the processing circuit is further configured to further control the order in which the battery packs are disconnected from the common traction voltage bus by opening the closed contactors in the following manner until all of the battery packs are disconnected: - in response to a first closed contactor having the lowest health level and the health level of the first closed contactor deviating from the average health level of all contactors by a value exceeding the first predetermined value, and in response to a second closed contactor having the lowest measured current and the measured current of the second closed contactor deviating from the average measured current of all contactors by more than the second predetermined value, opening the first closed contactor or the second closed contactor.

5. A computer system according to claim 4, wherein the processing circuit is further configured to open the first closed contactor before the second closed contactor in response to the percentage rate at which the health level of the first closed contactor deviates from the average health level of all contactors being higher than the percentage rate at which the measured current of the second closed contactor deviates from the average measured current of all contactors.

6. A computer system according to any one of claims 4 to 5, wherein the processing circuit is further configured to open the second closed contactor before the first closed contactor in response to the percentage rate at which the measured current of the second closed contactor deviates from the average measured current of all contactors being higher than the percentage rate at which the health level of the first closed contactor deviates from the average health level of all contactors.

7. The computer system of any one of claims 1 to 6, wherein the processing circuit is further configured to: receive measurement data from a plurality of sensors of the energy storage system, wherein the measurement data includes a measured current on each of a plurality of contactors.

8. The computer system of any one of claims 1 to 7, wherein the processing circuit is further configured to repeatedly determine the measured current across each of the plurality of contactors before each opening of the contactor.

9. The computer system of any one of claims 1 to 8, wherein the processing circuit is further configured to: after controlling the order in which the closed contactors are opened, connect at least two of the battery packs to the common traction voltage bus by closing the associated contactors, and thereafter: The battery pack is alternately connected and disconnected from the common traction voltage bus, wherein the sequence of controlling the closed contactors to open is performed for each disconnection.

10. A vehicle comprising a computer system according to any one of claims 1 to 9.

11. The vehicle of claim 10, further comprising: An energy storage system comprising at least two battery packs arranged in parallel and a switch arrangement comprising a plurality of contactors, each contactor being configured to connect and disconnect an associated battery pack of the energy storage system from a common traction voltage bus by closing and opening, respectively.

12. A computer-implemented method comprising: - determining, by a processing circuit of a computer system, a measured current across each of a plurality of contactors of a switching arrangement of an energy storage system of a vehicle, the energy storage system comprising at least two battery packs arranged in parallel, and each contactor being configured to connect and disconnect, by closing and opening, respectively, an associated battery pack of the energy storage system from a common traction voltage bus; - determining, by said processing circuit, a health level of each contactor; - controlling the order in which the battery packs are disconnected from the common traction voltage bus by the processing circuit by opening the closed contactors in the following manner until all the battery packs are disconnected: - in response to the health level of the contactors that are not closed deviating from the average health level of all contactors by more than a first predetermined value, opening said contactor associated with the lowest measured current, and - in response to the health level of the closed contactor with the lowest health level deviating from the average health level of all contactors by a value exceeding the first predetermined value and in response to the measured current of the non-closed contactors deviating from the average measured current of all contactors by more than a second predetermined value, opening the closed contactor with the lowest health level.

13. The method according to claim 12, further comprising: The health level of each contactor is determined by the processing circuit as an overall health level of the contactors.

14. The method according to any one of claims 12 to 13, further comprising: The health level of each contactor is determined by the processing circuit on a scale of 0% to 100%.

15. The method according to any one of claims 12 to 14, further comprising: The order in which the battery packs are disconnected from the common traction voltage bus is controlled by opening the closed contactors as follows until all the battery packs are disconnected: - in response to a first closed contactor having the lowest health level and the health level of the first closed contactor deviating from the average health level of all contactors by a value exceeding the first predetermined value, and in response to a second closed contactor having the lowest measured current and the measured current of the second closed contactor deviating from the average measured current of all contactors by more than the second predetermined value, opening the first closed contactor or the second closed contactor by the processing circuit.

16. The method according to claim 15, further comprising: In response to the percentage rate at which the health level of the first closed contactor deviates from the average health level of all contactors being higher than the percentage rate at which the measured current of the second closed contactor deviates from the average measured current of all contactors, the first closed contactor is opened before the second closed contactor by the processing circuit.

17. The method according to any one of claims 15 to 16, further comprising: The second closed contactor is opened before the first closed contactor by the processing circuit in response to the percentage rate at which the measured current of the second closed contactor deviates from the average measured current of all contactors being higher than the percentage rate at which the health level of the first closed contactor deviates from the average health level of all contactors.

18. The method according to any one of claims 12 to 17, further comprising: The measured current across each of the plurality of contactors is repeatedly determined by the processing circuit prior to each opening of the closed contactor.

19. A computer program product comprising program code for performing the method according to any one of claims 12 to 18 when executed by a processing circuit.

20. A non-transitory computer-readable storage medium comprising instructions which, when executed by a processing circuit, cause the processing circuit to perform the method of any one of claims 12 to 18.

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