Battery electromechanical switch device diagnostic system and method

Abstract

An electrical system including a battery system and a control system is disclosed. The battery system can include a first switch device (205), a first battery (209) electrically coupled in series with the first switch device, a second battery (211) electrically coupled in parallel with the first switch device and the first battery when the first switch device (205) is in a closed position, and a second switch device (207) coupled in series with a load (203). The control system can be configured to perform a diagnosis on the battery system.

Description

[0001] This application is a divisional application of the invention patent application filed on April 20, 2018, with international application number PCT / US2018 / 028664, national application number 201880025084.0, and entitled "Diagnostic System and Method for Battery Electromechanical Switch Device".

[0002] Related applications

[0003] This application claims priority to U.S. Provisional Patent Application No. 62 / 488,224, filed April 21, 2017, and also to U.S. Provisional Patent Application No. 62 / 616,308, filed January 11, 2018, the entire contents of which are incorporated herein by reference. Technical Field

[0004] This invention relates to the field of batteries, and more specifically to the field of battery diagnostics. background

[0005] Typically, a battery system may include one or more batteries that store electrical energy. Thus, battery systems are commonly used in electrical systems. Specifically, using the stored electrical energy, the battery can supply power to electrical loads in the electrical system, thereby discharging the battery. Additionally, the battery can capture electricity received from a power source (e.g., a generator) in the electrical system as electrical energy, thereby charging the battery.

[0006] In some cases, a battery system may include electromechanical switching devices (e.g., relays or contactors) electrically coupled between the battery and electrical equipment (e.g., loads or power sources) in the electrical system to facilitate control of the power supply from and / or to the battery. For example, in the closed position, the electromechanical switching device can electrically connect the battery to the electrical equipment. In other words, closing the electromechanical switching device allows current to flow, thereby charging / discharging the battery. On the other hand, in the open position, the electromechanical switching device can electrically disconnect the battery from the electrical equipment. In other words, opening the electromechanical switching device can prevent (e.g., inhibit) the flow of current, and thus prevent the charging / discharging of the battery cells.

[0007] To improve operational reliability, diagnostics can be performed on the battery system. For example, diagnostics can be performed to determine whether electromechanical switching devices are in the closed or open position. In other words, battery diagnostics can be performed to determine whether the battery cells are usable by the system.

[0008] For example, battery availability can be particularly important in a vehicle environment. Battery power may be needed for cold starts or to power standard vehicle functions such as air conditioning. Furthermore, the battery system can be used to support advanced vehicle features. These features may include lane assist, cruise control, and active suspension, among others. A power failure in these advanced features can lead to malfunctions of these features and potentially difficult situations for the driver.

[0009] Furthermore, with the increasing prevalence of advanced systems and features, vehicles rely on electrical systems that handle safety-critical loads. For example, lane-keeping assist and more advanced autonomous steering technologies may require vehicle systems to provide consistent power to the steering module within the vehicle. Drivers may depend on this capability. For instance, in semi-autonomous and fully autonomous vehicles with advanced vehicle systems, drivers may rely on these systems to operate the vehicle safely. Therefore, accurate battery diagnostics, including condition diagnostics of battery (or more generally, electrical) availability, can be crucial for ensuring safe vehicle operation.

[0010] In some situations, known diagnostics may be insufficient to detect battery availability. For example, known diagnostics may be affected when the current flowing through the battery is approximately zero, regardless of whether the electromechanical switching device is in the open or closed position. Such limitations reduce the accuracy of system information regarding power availability, which could lead to safety risks to the vehicle's electrical system. Summary of the Invention

[0011] Therefore, an improved battery diagnostic system and method are disclosed. This improved battery diagnostic system and method can be used, for example, in electrical systems to indicate the availability of one or more power sources. This improved battery diagnostic system and method allows confirmation of the availability of power sources used to support vehicle functions. The availability of the power source can be confirmed using an evaluation of the open or closed state of one or more switches in a circuit. In particular, the disclosed system and method can provide improved reliability of results regarding the battery state when the current flowing through the battery is approximately zero, regardless of whether the electromechanical switching device is in the open or closed position.

[0012] In various embodiments, the improved battery diagnostic systems and methods can be used in vehicles to enable vehicle functions that may include advanced vehicle features. Therefore, the improved battery diagnostic systems and methods can provide a higher level of accuracy in determining the availability of power for these functions.

[0013] Improved battery diagnostic systems and methods may include one or more switches in a circuit having at least two voltage sources. In various embodiments, the battery system includes a first battery, a second battery, a first switching device, a second switching device, and sensors communicatively coupled to a control system.

[0014] An electrical system is disclosed, comprising a battery system and a control system. The battery system includes: a first switching device; a first battery electrically coupled in series with the first switching device; a second battery electrically coupled in parallel with the first switching device and the first battery when the first switching device is in a closed position; and a second switching device coupled in series with a load. The control system is configured to perform diagnostics on the battery system. The control system is configured to: instruct the second switching device to close to electrically couple the second switching device and the load in parallel with the second battery; and determine the actual position of the first switching device based at least in part on the current flowing through the first battery when the second switching device is closed. An electrical system is also disclosed, wherein the control system is configured to instruct the second switching device to close when the battery system is in a steady state, wherein the current flowing through the first battery is approximately zero when the first switching device is in the closed position and the battery system is in a steady state. An electrical system is also disclosed, wherein the load includes a relay coil of the first switching device. An electrical system is also disclosed, comprising a current sensor coupled in series with the first switching device, wherein the control system is configured to determine the actual position of the first switching device based at least in part on a sensor signal received from the current sensor. An electrical system is also disclosed, wherein the current sensor includes a shunt resistor. An electrical system is also disclosed, wherein the actual position of the first switching device can be used to determine whether a first battery and / or a second battery is available for vehicle use. A vehicle having the disclosed electrical system is also disclosed. A vehicle is also disclosed in which the electrical system is used to assess whether the first battery and / or the second battery can support critical safety functions.

[0015] An electrical system is disclosed, comprising: a battery system and a control system configured to perform diagnostics on the battery system; the battery system further comprising a separate battery module having a positive terminal, a negative terminal, a battery cell, a primary switching device electrically coupled between the battery cell and the positive terminal, and a secondary switching device electrically coupled between the battery cell and the positive terminal and connected in parallel with the primary switching device. An electrical system is also disclosed, wherein the control system is configured to instruct the secondary switching device to close to electrically couple the battery cell to the positive terminal, and to determine the actual position of the primary switching device at least partially based on the voltage drop across the secondary switching device when the secondary switching device is closed.

[0016] An electrical system is disclosed, comprising a battery system and a control system. The battery system includes a first battery, a first switching device electrically coupled in series with a first load, a second switching device electrically coupled in series with a second load, a second battery, a sensor, and a relay. The first battery is electrically coupled in parallel with the first switching device, and the second battery is electrically coupled in parallel with the second switching device. The control system is configured to perform diagnostics on the battery system and is configured to determine the relay state by acquiring multiple measurements of the current flowing through the battery system. An electrical system is also disclosed, wherein the sensor is a current sensor including a shunt resistor. An electrical system is also disclosed, wherein the measurements include: a first current measurement obtained when both the first and second switching devices are open; a second current measurement obtained when the first switching device is closed and the second switching device is open; and a third current measurement obtained when the first switching device is open and the second switching device is closed. An electrical system is also disclosed, wherein the relay state can be used to determine whether the battery is usable in a vehicle. A vehicle is also disclosed, which further includes advanced driver functions. A vehicle is also disclosed, wherein the electrical system is used to assess whether the first and / or second batteries can support safety-critical functions.

[0017] These and other features and advantages of the devices, systems and methods according to the invention will be described or demonstrated in the following detailed descriptions of various examples. Attached Figure Description

[0018] Various embodiments of the systems, apparatus, and methods according to the present invention will be described in detail with reference to the following drawings, in which:

[0019] Figure 1 This is a schematic diagram of a battery system in a vehicle according to one or more embodiments described herein.

[0020] Figure 2 This is a cross-sectional view of a battery system in a vehicle according to one or more embodiments described herein.

[0021] Figure 3 This is a block diagram of an electrical system used in conjunction with the systems and methods described herein, according to one or more embodiments.

[0022] Figure 4 This is a block diagram of a battery system according to one or more embodiments described herein.

[0023] Figure 5 This is a second block diagram of a battery system according to one or more embodiments described herein.

[0024] Figure 6A This is a third block diagram of a battery system according to one or more embodiments described herein.

[0025] Figure 6B A graph showing the tracking current of a battery system according to one or more embodiments described herein is shown.

[0026] Figure 7A This is a fourth block diagram of a battery system according to one or more embodiments described herein.

[0027] Figure 7B An illustration shows one or more embodiments of a device described herein. Figure 7A A flowchart illustrating the workflow of a block diagram.

[0028] Figure 8 This is a fifth block diagram of a battery system according to one or more embodiments described herein.

[0029] Figure 9 An electrical system is shown that is used in conjunction with the systems and methods described herein, according to one or more embodiments.

[0030] Figure 10 A block diagram of a battery system according to one or more embodiments described herein is shown, wherein a load is illustrated.

[0031] Figure 11 A diagram showing a malfunction of a vehicle's safety components is provided.

[0032] These views are not necessarily shown to scale. In some cases, details that are not essential for understanding the invention or that make other details difficult to observe have been omitted. It should be understood, of course, that the invention is not limited to the specific embodiments shown herein. Detailed Implementation

[0033] This disclosure provides techniques for improving battery system diagnostics, for example, by increasing the accuracy of electromechanical switching device condition detection. Accurate electromechanical switching device condition detection allows electrical systems to confirm whether a specific voltage source (i.e., the battery) is available. Figure 1 As shown, the battery system 101 can be installed in the vehicle 103. The battery system 101 can be used to support the vehicle's electrical functions, including but not limited to advanced vehicle functions 105, the ignition system 119, and standard vehicle functions including a display 129. As described above, advanced vehicle functions can include semi-automatic or fully automatic functions, such as corrective steering or lane-keeping assist technology.

[0034] Figure 2A cross-sectional view of vehicle 103 is shown, which has a battery system 101 for electrical communication with the vehicle 103. The battery system 101 may include a first battery module 109 and a second battery module 111, both of which may include an energy storage component 107. Vehicle 103 may further include an engine 115, an alternator 117, an ignition system 119, and a control module 123, which may have a processor 125 and a memory 127. The energy storage component 107 is electrically coupled to the vehicle's electrical system via a bus 113. This allows power to be supplied to vehicle functions including electrical devices such as vehicle display 129 and advanced vehicle functions 105.

[0035] Figure 3 A simplified electrical system 201 is illustrated. It can be seen that the battery system 101, control system 124 (which may include a control module 123), and electrical devices 104 (e.g., advanced feature system 105 and a standard system including a display 129) are electrically communicating with each other. In some embodiments, the electrical system may be included in a motor vehicle 103 or a similar location. Additionally, in some embodiments, the electrical devices may include electrical loads and / or power sources (e.g., generators) 203.

[0036] Furthermore, in some embodiments, the control system 124 may control the operation of the battery system 101 and / or electrical equipment 104. For example, in a motor vehicle 103, the control system 124 may include a battery management system (BMS) and / or a vehicle control unit (VCU). In some embodiments, the control system 124 may additionally or alternatively perform diagnostics on the battery system 101, such as to determine the state (e.g., position) of electromechanical switching devices implemented in the battery system.

[0037] More detailed views of the battery system according to various embodiments are available in Figure 4 As shown in the figure. In the depicted embodiment, the battery system includes a first battery 209, a second battery 211, a first switching device 205, a second switching device 207, and a sensor 213 communicatively coupled to the control system 224. In some embodiments, the first battery 209 and the second battery 211 may be implemented by battery cells in one or more battery modules (109, 111). For example, the first battery 209 may be implemented in the first battery module 109, and the second battery 211 may be implemented in the second battery module 111. Additionally or alternatively, the first battery 209 and the second battery 211 may be implemented in the same battery module.

[0038] As described above, the control system 224 can control the operation of the battery system 201. For example, the control system 224 can instruct the first switching device 205 to switch from an open position to a closed position, or from a closed position to an open position. In some embodiments, the first switching device 205 can be an electromechanical switching device, such as a bistable relay. Additionally or alternatively, the control system can instruct the second switching device 207 to switch from an open position to a closed position, or from a closed position to an open position. In some embodiments, the second switching device can be a semiconductor switching device, such as a metal-oxide-semiconductor field-effect transistor (MOSFET) or a bipolar junction transistor (BJT).

[0039] In addition to control operations, the control system 224 can perform diagnostics at least in part based on the operating parameters of the battery system 201. Therefore, to facilitate diagnostics, the control system 224 can receive sensor signals from sensor 213 that indicate the operating parameters of the battery system 201. For example, based on the sensor signals received from sensor 213 (e.g., a shunt resistor), the control system can determine the current flowing through the first battery 209.

[0040] Specifically, when in the closed position, the first switching device 203 allows current to flow through the first battery 209. Thus, when a sensor signal received from sensor 213 indicates that the current flowing through the first battery 209 is greater than a threshold current (e.g., zero amperes), the control system 224 can determine that the first switching device 203 is in the closed position. Conversely, when in the open position 217, the first switching device 205 can block (e.g., disable) the current flowing through the first battery 209. Thus, in some embodiments, when a sensor signal received from sensor 213 indicates that the current flowing through the first battery 209 is not greater than a threshold current, the control system 224 can determine that the first switching device 203 is in the open position 217.

[0041] However, in some cases, even when the first switch 205 is in the closed position 215, the current flowing through the first battery 209 may not exceed the threshold current. For example, when the vehicle is off, the battery system can continue to supply power to one or more electrical devices 204. When the first switch is in the closed position 215, the first battery 209 and / or the second battery 211 can output power until a steady state (e.g., equilibrium) is reached, for example, due to energy transfer between the first battery 209 and the second battery 211. In some cases, in the steady state, the voltage of the first battery 209 and the voltage of the second battery 211 may be approximately equal, resulting in the current in the battery system 201 being approximately zero even when the first switch 205 is in the closed position 215, and therefore, the current flowing through the first battery 209 is also approximately zero.

[0042] In other words, when the battery system 201 is in a steady state, the current flowing through the first battery 209 can be approximately zero regardless of whether the first switching device 205 is in the open position 217 or the closed position 215. Furthermore, as mentioned above, when the first switching device 205 is in the open position 217, the current flowing through the first battery 209 can also be approximately zero regardless of whether the battery system 201 is in a steady state. Therefore, when the battery system is in a steady state, known systems and methods may make it difficult for the control system 224 to determine the position of the first switching device 205.

[0043] To facilitate determining the position of the first switching device 205, the control system 224 can control the switching of the second switching device 207. Typically, the control system 224 can hold the second switching device 207 in the open position 217, thereby disconnecting the load from either the positive bus 219 or the negative bus 221. When the second switching device 207 is switched to the closed position 215, the load 203 can be electrically coupled between the positive bus 219 and the negative bus 221, resulting in current flowing through the load 203. In practice, introducing a load may cause the battery system 201 to exit a steady state. For example, when the battery system 201 is in a steady state and the first switching device 205 is in the closed position 215, closing the second switching device 207 to introduce the load 203 may cause current to flow through the first battery 209 and the second battery 211.

[0044] Thus, in some embodiments, the control system 224 may instruct the second switch 207 to close whenever the position of the first switch 205 needs to be determined. As described above, when the battery system 201 is not in a stable state, the current flowing through the first battery 209 can indicate the position of the first switch 205. Thus, in some embodiments, the control system may determine whether the battery system 201 is expected to be in a stable state, and when the battery system 201 is expected to be in a stable state and the position of the first switch 205 is to be determined, instruct the second switch 211 to close. Operating in this way can help reduce power loss by reducing the duration for which the load 203 is in a connected state.

[0045] Even when the battery system 201 is in a stable state, the introduction of the load 203 enables the control system 224 to determine the position of the first switching device 205. For example, when the load 203 is connected, and the current flowing through the first battery 209 is greater than a threshold current (e.g., zero amperes), the control system 224 can determine that the first switching device 205 is in the closed position 215. On the other hand, when the current flowing through the second battery 211 is not greater than the threshold current, the control system 224 can determine that the first switching device 209 is in the open position 217.

[0046] Additionally, in some embodiments, the load 203 selectively connected by the second switching device 207 may be an existing component in the battery system 201. For example, the load 203 may be the relay coil 204 of the first switching device 205. In such an embodiment, the control system 124 may instruct the second switching device to apply a pulse to the relay coil such that the power supplied to the relay coil 204 is insufficient to switch the first switching device 205. Implementing the load in this way can help reduce implementation-related costs, such as the number of components in the battery system 201, the manufacturing steps involved in assembling the battery system 201, and / or the size of the battery system 201 (e.g., floor space).

[0047] Furthermore, determining the position of the first switching device 205 can aid in performing other diagnostics. For example, when the first switching device 205 is expected to be in the open position 217 but a sensor signal indicates that the first switching device 205 is actually in the closed position 215, the control system 224 can determine that the first switching device 205 is soldered to or otherwise undesirably held in the closed position 215. Additionally or alternatively, when the first switching device is expected to be in the closed position 215 but a sensor signal indicates that the first switching device 205 is actually in the open position 217, the control system 124 can determine that the first switching device 205 is blocked or otherwise undesirably held in the open position 217.

[0048] In addition to facilitating the diagnosis of multi-cell battery systems, this disclosure also provides techniques for diagnosing individual (e.g., standalone) cells. To aid in illustration, Figure 5 The image shows an independent battery system 301.

[0049] As depicted, the standalone battery module 301 includes one or more battery cells, a primary switching device 305, and a secondary switching device 307. Specifically, in the depicted embodiment, the primary switching device 305 and the secondary switching device 307 are connected in parallel between the battery cell 303 and the positive terminal 309 of the battery module 301. In other embodiments, the primary switching device 305 and the secondary switching device 307 may be connected in parallel between the battery cell 303 and the negative terminal 311 of the battery module 301.

[0050] Additionally, in some embodiments, the primary switching device 305 and / or the secondary switching device 307 can help control the direction of current flowing through the battery cell 303. For example, the secondary switching device 307 may include a diode configured to allow current to flow from the battery cell 303 to the positive terminal 309, thereby enabling the battery cell 303 to discharge only through the secondary switching device 307. Alternatively, the secondary switching device 307 may include a diode configured to allow current to flow from the positive terminal 309 to the battery cell 303, thereby enabling the battery cell 303 to be charged only through the secondary switching device 307.

[0051] Furthermore, in some embodiments, the primary switching device 305 and / or the secondary switching device 307 can help control the magnitude of the current flowing through the battery cell 303. For example, the primary switching device 305 and the secondary switching device 307 can be configured such that, when closed, the secondary switching device 307 limits the magnitude of the current compared to the primary switching device 305. In other words, in some embodiments, the primary switching device 305 can be closed when a larger current is desired to flow through the battery cell 303, such as during a cold start of the internal combustion engine; and the secondary switching device 307 can be closed when a smaller current flowing through the battery cell 303 is sufficient, such as when powering a radio while the vehicle is off. Therefore, in some embodiments, the primary switching device 305 may include an electromechanical switching device (e.g., a relay or contactor). Additionally, in some embodiments, the secondary switching device 307 may include a semiconductor switching device, such as a metal-oxide-semiconductor field-effect transistor (MOSFET) or a bipolar junction transistor (BJT).

[0052] For example, diagnostics can be performed on the independent battery module 301 to determine the position of the primary switching device 305 and / or whether the primary switching device 305 is operating normally. In some embodiments, the voltage drop across the secondary switching device 307 can indicate the position of the primary switching device 305. For example, when the primary switching device 305 is in the open position, the voltage drop across the primary switching device 305 and therefore the voltage drop across the secondary switching device 307 may be higher than a threshold voltage (e.g., zero volts). On the other hand, when the primary switching device 305 is in the closed position, the voltage drop across the primary switching device 305 and therefore the voltage drop across the secondary switching device 307 may not be higher than a threshold voltage. Therefore, the system can instruct the secondary switching device 307 to close, and then, during the closure of the secondary switching device 307, determine the actual position of the primary switching device 305, the actual position of the secondary switching device 307, or the actual position of both the primary switching device 305 and the secondary switching device 307, at least in part, based on the voltage drop across the primary switching device 305 or the secondary switching device 307.

[0053] In some embodiments, to facilitate drawing sufficient current from battery cell 303 to generate a voltage drop across secondary switching device 307, load 319 may be selectively coupled between the positive terminal 309 and negative terminal 311 of the battery module via a third switching device 313. For example, in the open position, the third switching device 313 may electrically disconnect load 319 from the terminals of battery module 301. On the other hand, in the closed position, the third switching device 313 may electrically connect load 319 to the terminals (309, 311) of battery module 301. Thus, in such embodiments, when the position of primary switching device 305 is to be determined, control system 324 may instruct third switching device 313 to switch to the closed position. Additionally, in some embodiments, the switchable load 319 may be an internal component of battery module 301, such as the relay coil of primary switching device 305. In such embodiments, this allows for diagnostics to be performed before battery module 301 is deployed in an electrical system, such as while it is on a shelf. In other embodiments, the switchable load may be external to battery module 301.

[0054] To facilitate diagnostics on the independent battery module, the control system 315 can receive sensor signals from a sensor 317 (e.g., voltage) connected across the secondary switch 307. The control system 315 can determine the actual position of the primary switch 305 based at least in part on the sensor signals. Furthermore, the control system 315 can perform further diagnostics based at least in part on the actual position of the primary switch 305. For example, the control system 315 can determine whether the primary switch 305 is functioning correctly by comparing the actual position of the primary switch 305 with its expected position.

[0055] The systems and methods described above may have certain limitations, such as when the difference between the first and second resistances is significant. This may occur, for example, when the system contains two batteries with increasing resistance values. For instance, the resistance value may increase at extreme temperatures (e.g., very cold temperatures). Therefore, additional features or diagnostic techniques may be beneficial in complementing the above. Figure 6A , Figure 7A , Figure 8 and Figure 9 Many circuits used in conjunction with the aforementioned systems and methods are shown. Figure 4 and Figure 5Compared to the circuits (battery systems 201, 301), these circuits (battery system 401) may further include one or more additional loads, additional switches, and changes to diagnostic procedures. Therefore, it should be understood that the systems and methods described above can be supplemented by those already described. This is because the systems and methods described herein and below can, in certain circumstances, enhance the effectiveness of the systems and methods described above. Therefore, it should be understood that similar techniques, objectives, and features also apply to the foregoing. These include, but are not limited to, the type of voltage source (lithium-ion battery, lead-acid battery, alternator, other voltage sources), the type of load (resistor, relay coil, equivalent), switching devices, sensors, the type of control system, etc.

[0056] like Figure 6A As shown, battery system 401 may include a first voltage source or battery 409, a second voltage source or battery 411, a first switching device 405 and a second switching device 407, and a sensor or shunt 413. Compared to what has been disclosed, the battery system may include multiple additional loads. A first load 415, a second load 417, and possibly a third load 419 and a fourth load 420 can be seen. Although certain resistors (R1, R2, etc.) are shown and named, they can be broadly understood to cover some type of load. Control system 424 may also communicate with sensor or shunt 413.

[0057] Diagnostics can be performed even when the first and second resistances of the first and second batteries (409, 411) are large (e.g., at very cold temperatures) by providing one or more additional loads (415, 417) on the system. For example, in various embodiments, the systems and methods described herein may involve providing additional current loads (e.g., 415, 417) to the bus side; in other words, for example, with... Figure 4 In contrast, additional current loads 415 and 417 are provided to the other side of the relay 423 and sensor 413 (e.g., a shunt). It should be understood that... Figure 6A The status of relay 423 is being evaluated in the system. Figure 4 and Figure 5 In the present case, the state of SW1 (205, 305) is being evaluated. In other words, in various embodiments, a first load can be provided on one side of the relay and shunt of the example circuit provided herein, and a second load can be provided on the other side of the relay and shunt.

[0058] It is obvious that, Figure 6AIn this configuration, a first voltage source 409 is electrically connected in series with a load (e.g., a first resistor) 415. They are electrically connected in parallel with a first switching device 405, which may be connected in series with another load (e.g., resistor I balance). A second voltage source 411 is seen to be electrically connected in series with a load (e.g., a second resistor) 417. They are electrically connected in parallel with a second switching device 407, which may be connected in series with another load (e.g., resistor I coil). Between the switches, a relay 423 is visible. The relay 423 may be constructed from some type of circuit breaker, including but not limited to fuses, relays, etc. The relay 423 may be positioned along a bus, which in some embodiments may be a bus critical to battery functionality. Similarly, a sensor (e.g., a shunt) 413 can be seen between loads 419 and 421.

[0059] The systems and methods described herein, employing two techniques, advantageously allow for condition assessment regardless of the impedance of each voltage source (e.g., 409, 411). This enables diagnostics even when there is a significant difference in resistance between the two sides. In particular, it allows for diagnostics when the voltages between the two power sources (e.g., the first battery 409 and the second battery 411) are substantially the same, but there is a large difference in resistance between the two sides. The systems and methods described herein are especially advantageous when the voltages on both sides (e.g., the first battery side 409 and the second battery side 411) are the same but the resistance difference is large.

[0060] In the aforementioned system and method, load 203 may have been included on the positive side to allow current to flow on one side of circuit 201. The aforementioned system and method can therefore allow similar diagnostics to operate in the opposite manner (relative to the above disclosure), searching for current as it flows through sensor (e.g., shunt) 413. In the case where the first resistor 415 is much larger than the second resistor 417 (the resistance on one side is much greater than the resistance on the other), the preceding... Figures 1 to 5 The systems and methods disclosed may be insufficient. In other words, existing systems may lose effectiveness when the difference between the first resistor and the second resistor (e.g., the discharge resistance of the LI system and the discharge resistance R0 of the battery cell, "Rpack and Rbus") becomes large. By using... Figures 1 to 5 The systems and methods described above, as well as the systems and methods disclosed below (i.e., used together), can achieve excellent results in certain situations, resulting in more reliable battery status indications.

[0061] like Figure 6BAs shown, the aforementioned system and method can be used to compare the current difference between the I shunts flowing through the above test (I coil) and the aforementioned (supplementary) test (I balance), which will be further described below, as described in more detail below. In other words, I shunt (“I coil” test) can be calculated using the current flowing through the fourth resistor (R coil) 421, the current flowing through the first battery 409, the current flowing through the second battery 411, the resistance of the first resistor 415, and the resistance of the second resistor 419. Similarly, I shunt (“I Balance” test) can be calculated using the current flowing through the third resistor (R balance) 419, the current flowing through the first battery 409, the current flowing through the second battery 411, the resistance of the first resistor 415, and the resistance of the second resistor 419.

[0062] In more detail, Figure 7A and Figure 7B The first circuit and the diagnostic algorithm are shown respectively. Similarly, in... Figure 7A In the circuit, on the first side (here, the left side) relative to the sensor or shunt 413, a first voltage source 409, a first resistor (load) 417, a first switching device 405, and a third resistor (load, also called R balance) can be seen. A relay (circuit breaker, such as a relay or fuse) 423 can also be seen. On the opposite side of the sensor or shunt 413 are a second voltage source 411, a second switching device 407, a second resistor or load 419, and a fourth resistor or load (also called R coil), which constitute the second side of the circuit or battery system 401. Example currents (I1, I2, I shunt) indicating the currents used for measurement can be seen.

[0063] Figure 7B An overview of a series of measurements captured by sensor 413 by the system and method of this document for evaluating the state of a relay is shown. The following non-limiting methods may be used in various embodiments of the system of this document (although some steps are described, these steps and their order are non-limiting; various arrangements thereof should be considered within the scope of this disclosure).

[0064] First, in step 451, current A is obtained by acquiring the median current from sensor 413. In this step, controller 424 instructs both switch 1 (405) and switch 2 (407) to be open. In steps 453 and 455, current B is obtained by acquiring the median discharge current from V1 409. In this step, controller 424 instructs switch 1 (405) to be open and switch 2 (407) to be closed. In step 457, current C is obtained, where current C is also the median current. In this step, controller 424 instructs both switch 1 (405) and switch 2 (407) to be open. In steps 459 and 461, current D is obtained. Current D is the median charging current from V2 411. In this step, controller 424 instructs switch 1 (405) to be closed and switch 2 (407) to be open. In step 463, current E is obtained, where current E is also the median current. In this step, controller 424 instructs both switch 1 (405) and switch 2 (407) to be open. In step 465, this data is used to determine the state.

[0065] The following expands on the steps discussed above with further detail. Generally, it can be assumed that the relay status diagnosis disclosed herein can be requested when the first voltage source 409 (VPACK, V1) and the second voltage source 411 (VBUS, V2) (which in various embodiments may be the first and second battery voltages, e.g., lithium-ion and lead-acid batteries) are similar and the battery current is close to zero. When requested, the relay status diagnosis can be performed using the following procedure, which in various embodiments may be configured to... Figure 7B Changes or extensions to the related descriptions. Although a specific duration is disclosed, it should be understood that shorter and longer durations are possible within the scope of this disclosure.

[0066] In step 451, controller 424 (which may include an MCU in various embodiments) may sample the battery current for a duration of approximately 5-10 ms, more specifically approximately 10 ms, and take the median of the samples obtained during this period. This value is set as CURRENT_A (e.g., current A can also be understood as Ishunt / Ishunt nominal value).

[0067] In step 453, the controller may then enable relay status diagnostics for a duration of approximately 10-30 ms, more specifically approximately 20 ms. In various embodiments, this step performed by the controller may include: the MCU sending an SPI command to request the FPGA to enable relay status diagnostics for a duration of approximately 10-30 ms, more specifically approximately 20 ms.

[0068] In step 455, when relay status diagnostics of the load are enabled, the controller can sample the current and obtain the median value. More specifically, for example, during approximately 10-30 ms (more specifically approximately 20 ms) after the FPGA has enabled relay status diagnostics of the load, the MCU can sample the battery current and take the median of the sampled values ​​obtained during this period. This value is set as CURRENT_B (e.g., current B can be understood as I Coil in the diagram).

[0069] In step 457, the controller samples the battery current to obtain a median sampled value. More specifically, for example, after the FPGA has disabled relay status diagnostics for the load (approximately 10-30 ms, especially after approximately 20 ms), the MCU can sample the battery current for about 10 ms and take the median of the sampled values ​​obtained during this period. This value is set to CURRENT_C (e.g., the current C can be understood as the nominal value of Ishunt / Ishunt in the diagram).

[0070] In step 459, battery cell balancing can be performed. More specifically, for example, the MCU can perform battery cell balancing on multiple balancing circuits (e.g., six balancing circuits) for approximately 10-30 ms, more specifically approximately 20 ms.

[0071] In step 461, the median current can also be obtained. More specifically, for example, approximately 10-30 ms after the MCU has enabled battery balancing, and more specifically, during a period of approximately 20 ms, the MCU can sample the battery current and take the median of the samples obtained during that time period. This value is set to CURRENT_D (e.g., the current D can be understood as Ibalance in the attached figure).

[0072] In step 463, the median current can also be obtained, for example, via controller 424. More specifically, for example, after the MCU has disabled battery cell balancing (approximately 10-30 ms, more specifically approximately 20 ms), the MCU can sample the battery current for a duration of approximately 5-10 ms, more specifically approximately 10 ms, and take the median of the sampled values ​​obtained during this period. This value is set as CURRENT_E (e.g., the current E can be understood as the nominal value of I shunt / I shunt in the figure).

[0073] Although a specific duration is provided, those skilled in the art will understand that variations in duration are within the scope of this disclosure. The following logic can be applied to tests to determine the state of a relay. This logic is a non-limiting method for determining, for example, the state of a relay using example logic.

[0074] The controller 424, which may include the MCU, can determine that the relay 423 is closed if the following conditions are met:

[0075] 1. The difference between CURRENT_A current A, CURRENT_C current C, and CURRENT_E current E exceeds X (which can be approximately 5-20, more specifically approximately 10, as a placeholder for X) milliamps.

[0076] 2. Absolute value (CURRENT_D current D – CURRENT_B current B) – Absolute value (average value (CURRENT_A current A, CURRENT_C current C, CURRENT_E current E)) >= X (approximately 20-50, more specifically approximately 40, can be used as a placeholder for X) milliamps.

[0077] The controller 424, which may include the MCU, can determine that the relay 423 is open if the following conditions are met:

[0078] 1. The difference between CURRENT_A current A, CURRENT_C current C, and CURRENT_E current E does not exceed X (which can be a placeholder for X, approximately 5-20, more specifically approximately 10) milliamps.

[0079] 2. Absolute value (CURRENT_D current D – CURRENT_B current B) – Absolute value (average value (CURRENT_A current A, CURRENT_C current C, CURRENT_E current E)) <= X (approximately 5-20, more specifically approximately 10, can be used as a placeholder for X) milliamps.

[0080] If none of the above conditions are met, the MCU, including its controller 424, can determine that the relay 423 is in an indeterminate state. Similarly, the examples of logic used to determine the relay state are non-limiting. Variations or substitutions of this logic should be considered within the scope of this disclosure.

[0081] Figure 8Another example electronic system for use with the systems and methods described herein is shown. Similarly, a first voltage source (shown here as a lithium-ion battery) 409 can be configured in series with a first load 415. Another load 419 can be configured in series with a first switch 405, and the load 419 and the first switch 405 can be connected in parallel with the first voltage source 409 and the first resistor 415. A second voltage source (shown here as a lead-acid battery) 411 can be configured in series with a second load 417. They can be configured to be connected in parallel with a second switching device 407 and an additional load 421. A circuit breaker (fuse, relay) 423, which can be configured along a bus, is shown between loads 421 and 419. A sensor 413 is also configured between the first switching device 405 and the second switching device 407. The sensor 413 can communicate with a controller 424. Typically, the controller 424 can communicate with any disclosed electrical system to implement the functions disclosed herein.

[0082] Figure 9 A block diagram of another example electronic system used in conjunction with the systems and methods described herein is shown. Expanding on the previous circuitry, an alternator 425 (an alternator can generally be understood as an additional voltage source) and a safety load 427 are shown. This load 427 can support safety features within the vehicle. As mentioned above, some loads may be "safety-critical" to support certain features within the vehicle. Other loads may be less important relative to safety. For example, as the system becomes more automated, they may become more power-intensive and more critical to safety. Figure 9 The circuit includes a safety load support section 429 and a load support bus 431. In other words, in various embodiments, vehicle safety could be adversely affected if the power supply to this section of the circuit fails. Therefore, accurate diagnostics and information regarding power availability (e.g., via circuit breaker / relay 423) may be important.

[0083] Vehicle safety and chassis functions can be further categorized using Automotive Safety Integrity Levels (ASILs). (ASIL D can be understood as the highest integrity requirement, while ASIL A can be understood as the lowest integrity requirement). For each of these components, there are corresponding power supply requirements based on a certain ASIL integrity level (e.g., ASIL D). This standard may include requirements for low current levels and redundancy in power support. Furthermore, automated functional features may require safety-critical peak current loads (>100, 200 amps). This may involve combinations of power supplies. These safety-critical controllers and higher power peak loads can all be located on the same network; therefore, if the power supply for the entire vehicle fails and cannot provide peak loads, there will also be power loss to the safety-critical controllers. Therefore, in various embodiments, diagnostics, particularly regarding relay status, can periodically verify the functionality of battery relay controls to ensure that the battery is connected (relay closed, fuse connected) and able to provide power.

[0084] Figure 10 A 12V network 475 is shown, which can be used in various embodiments to support loads with ASIL C power integrity requirements. The system may include a first battery 409 (which may include a lead-acid battery) supporting multiple characteristics and having a specific quality factor (Q<_), a second battery 411, and an alternator 425.

[0085] Figure 11 A block diagram depicting possible areas of vehicle safety malfunction 501 is shown. System 503, including power steering 511 and associated safety ECUs and sensors 513 for controlling direction, may be susceptible to vehicle safety malfunction. Next, system 505, including brake control (ESC) 515 and associated safety ECUs and sensors 513 for controlling speed, may also be susceptible to vehicle safety malfunction. System 507, including actuators 517 and associated safety ECUs and sensors 513 for supporting active suspension, may also be susceptible to vehicle safety malfunction. Finally, a power supply network 509 supporting system 519, including a source / storage failure providing power to ADAS (Advanced Driver Assistance Systems), may be susceptible to vehicle safety malfunction.

[0086] Therefore, it should be understood that the disclosed systems and methods can allow for improved accuracy in battery diagnostics. In particular, in various embodiments, the disclosed systems and methods can allow for improved accuracy in relay status. Relay status can enable the system to indicate the availability of one or more power supplies.

[0087] As used herein, the terms “approximately,” “almost,” “generally,” and similar terms are intended to have a broad meaning and are consistent with usage commonly used and accepted by one of ordinary skill in the art to which the subject matter of this disclosure pertains. Those skilled in the art will understand upon careful reading of this disclosure that these terms are intended to describe certain features described and claimed, and not to limit the scope of these features to the given precise numerical ranges. Therefore, these terms should be interpreted as indicating that non-substantial or insignificant modifications or variations to the described and claimed subject matter are considered to fall within the scope of the invention as set forth in the appended claims.

[0088] It should be noted that references to relative positions (e.g., "above" and "below") in the specification are used only to determine the orientation of the individual components in the drawings. It should be recognized that the orientation of a particular component can vary considerably depending on the application in which it is used.

[0089] For the purposes of this disclosure, the term "coupled" means two parts that are directly or indirectly joined together. This joining can be substantially fixed or removable. Such joining can be achieved by the two parts, or by the two parts and any additional intermediate parts that form a single unified entity with or with the two parts, or by the two parts and additional intermediate parts that are attached to each other. Such joining can be substantially permanent, removable, or detachable.

[0090] It is equally important to note that the construction and arrangement of the systems, methods, and apparatuses shown in the various embodiments are illustrative only. Although only some embodiments are described in detail in this disclosure, those skilled in the art will readily understand, upon close reading of this disclosure, that many modifications can be made (e.g., variations in the size, dimensions, structure, shape, and proportions of individual components, parameter values, installation arrangements, use of materials, color, orientation, etc.) without materially departing from the novel teachings and advantages of the subject matter. For example, the monolithically formed component shown may be made of multiple components, or the component shown as being composed of multiple components may be integrally formed; the operation of the interface may be reversed or otherwise altered; the structure of the system or the length or width of components or connectors or other parts may be varied; the characteristics or number of adjustment positions provided between components may be varied (e.g., variations in the number of engagement slots or the size or type of engagement slots). According to alternative embodiments, the order or sequence of any process or method steps may be changed or reordered. Other substitutions, modifications, or omissions may be implemented in the design, operating conditions, and arrangements of the various embodiments without departing from the spirit or scope of the invention.

[0091] Although the invention has been described in conjunction with the embodiments given above, various alternatives, modifications, variations, improvements, and substantial equivalents will be apparent to those skilled in the art, whether they are known or currently foreseeable. Therefore, the embodiments of the invention set forth above are intended to be illustrative rather than limiting. Many changes can be made without departing from the spirit and scope of the invention. Therefore, the invention is intended to cover all known or previously formed alternatives, modifications, variations, improvements, and / or substantial equivalents.

[0092] The technical effects and problems described in this specification are exemplary and not limiting. It is worth noting that the examples described in this specification may have other technical effects and can solve other technical problems.

Claims

1. An electrical system, the electrical system comprising: The battery system includes: First switching device; The first battery is connected in series with the first switching device; The second battery, when the first switch is in the closed position, is electrically coupled in parallel with the first switch and the first battery; and A second switching device, wherein the second switching device is coupled in series with the load; The control system is configured to perform diagnostics on the battery system, and the control system is configured to: Instructing the second switching device to close, so as to electrically couple the second switching device and the load in parallel to the second battery; and The actual position of the first switching device is determined at least in part based on the current flowing through the first battery when the second switching device is closed; The control system is configured to instruct the second switch to close when the battery system is in a stable state, wherein when the first switch is in the closed position and the battery system is in the stable state, the current flowing through the first battery is approximately zero.

2. The electrical system according to claim 1, wherein the load includes the relay coil of the first switching device.

3. The electrical system of claim 1, wherein the actual position of the first switching device can be used to determine whether the first battery and / or the second battery can be used by the vehicle.

4. A vehicle having an electrical system according to claim 3.

5. The vehicle of claim 4, wherein the electrical system is used to evaluate whether the first battery and / or the second battery can support safety-critical functions.

6. An electrical system, the electrical system comprising: The battery system includes: First switching device; The first battery is connected in series with the first switching device; The second battery, when the first switch is in the closed position, is electrically coupled in parallel with the first switch and the first battery; and A second switching device, wherein the second switching device is coupled in series with the load; The control system is configured to perform diagnostics on the battery system, and the control system is configured to: Instructing the second switching device to close, so as to electrically couple the second switching device and the load in parallel to the second battery; and The actual position of the first switching device is determined at least in part based on the current flowing through the first battery when the second switching device is closed; and A current sensor, wherein the current sensor is coupled in series with the first switching device; The control system is configured to determine the actual position of the first switching device based at least in part on sensor signals received from the current sensor.

7. The electrical system of claim 6, wherein the current sensor comprises a shunt resistor.

8. The electrical system of claim 6, wherein the actual position of the first switching device can be used to determine whether the first battery and / or the second battery can be used by the vehicle.

9. The electrical system of claim 6, wherein the control system is configured to instruct the second switching device to close when the battery system is in a stable state, wherein when the first switching device is in the closed position and the battery system is in the stable state, the current flowing through the first battery is approximately zero.

10. The electrical system of claim 6, wherein the load comprises the relay coil of the first switching device.

11. A vehicle having an electrical system according to claim 8.

12. The vehicle of claim 11, wherein the electrical system is used to evaluate whether the first battery and / or the second battery can support safety-critical functions.

13. An electrical system comprising: The battery system includes: A first battery, the first battery having a positive terminal and a negative terminal; A first switching device, wherein the first switching device is electrically coupled in series with a first load; A second switching device is connected in series with a second load and electrically coupled. A second battery, the second battery having a positive terminal and a negative terminal; A sensor, electrically coupled between the negative terminal of the first battery and the negative terminal of the second battery; and A relay, which is electrically coupled between the positive terminal of the first battery and the positive terminal of the second battery; The first battery is electrically coupled in parallel with the first switching device and the first load; the second battery is electrically coupled in parallel with the second switching device and the second load; the sensor is electrically coupled between the first switching device and the second switching device; and the relay is electrically coupled between the first switching device and the second switching device. A control system configured to perform diagnostics on the battery system, the control system being configured to determine the relay state by obtaining multiple measurements of the current flowing through the battery system.

14. The electrical system of claim 13, wherein the sensor is a current sensor including a shunt resistor.

15. The electrical system of claim 13, wherein the measured value includes: When both the first switching device and the second switching device are in the open state, the first current measurement value is obtained; When the first switching device is closed and the second switching device is open, a second current measurement value is obtained; A third current measurement value is obtained when the first switching device is open and the second switching device is closed.

16. The electrical system of claim 13, wherein the state of the relay can be used to determine whether the battery can be used by the vehicle.

17. A vehicle having an electrical system according to claim 13.

18. The vehicle of claim 17, further comprising advanced driver functionality.

19. The vehicle of claim 17, wherein the electrical system is used to evaluate whether the first battery and / or the second battery can support safety-critical functions.

20. An electrical system comprising: The battery system includes: Positive terminal; Negative terminal; Battery cell; Primary, electromechanical switching devices; and Secondary semiconductor switching device, wherein the secondary switching device is electrically coupled to the primary switching device in a parallel relationship, and the primary switching device and the secondary switching device are electrically coupled to one of the positive terminal and the negative terminal and the battery cell in a series relationship. A voltage sensor, coupled to the battery system, is used to detect a voltage drop across the secondary switching device; and A control system coupled to the sensor, the primary switching device, and the secondary switching device, the control system being configured to perform diagnostics on the battery system and also configured to control the primary and secondary switching devices. When the primary switching device is closed, a first-order current is allowed to flow through the primary switching device, and when the secondary switching device is closed, a second-order current is allowed to flow through the secondary switching device, wherein the first-order current is greater than the second-order current.

21. The electrical system of claim 20, wherein the primary switching device and the secondary switching device are electrically coupled between the battery cell and the positive terminal, or The primary switching device, the secondary switching device, or both control the direction of the current flowing through the battery cell, and The secondary switching device includes a diode to control the direction of current flowing through the secondary switching device, or The primary switching device, the secondary switching device, or both control the magnitude of the current flowing through the battery cell, or The electrical system also includes a third switching device and a load electrically coupled between the positive terminal and the negative terminal.

22. A method of operating an electrical system according to claim 20, the method comprising: The secondary switching device is instructed to close to electrically couple the battery cell to one of the positive terminal and the negative terminal. and During the closing of the secondary switching device, the actual positions of the primary switching device, the secondary switching device, or both the primary and secondary switching devices are determined based on the voltage drop across the secondary switching device.

23. The method of claim 22, further comprising determining, during the closing of the secondary switching device, whether the primary switching device is operating normally based on the voltage drop across the secondary switching device, or The expected position of the primary switching device is determined, the actual position of the primary switching device is determined based on the voltage drop on the secondary switching device, and whether the primary switching device is operating normally is determined based on the expected position and the actual position of the primary switching device.

24. A method of operating an electrical system according to claim 21, the method comprising: Indicates that the third switching device is closed; The secondary switching device is instructed to close to electrically couple the battery cell to one of the positive terminal and the negative terminal. as well as During the closing of the secondary switching device, the actual position of the primary switching device is determined based on the voltage drop across the secondary switching device.

25. An electrical system comprising any one of the technical features of claims 1-3 or any combination thereof.

26. A vehicle comprising any one of the technical features of claims 4-5 or any combination thereof.

27. An electrical system comprising any one of the technical features of claims 6-10 or any combination thereof.

28. A vehicle comprising any one of the technical features of claims 11-12 or any combination thereof.

29. An electrical system comprising any one of the technical features of claims 13-16 or any combination thereof.

30. A vehicle comprising any one of the technical features of claims 17-19 or any combination thereof.

31. An electrical system comprising: The battery system includes a positive terminal, a negative terminal, a battery cell, a primary switching device with an electromechanical switching mechanism, and a secondary switching device with a semiconductor switching mechanism. The secondary switching device is electrically coupled to the primary switching device in a parallel connection, the parallel connection of the primary switching device and the secondary switching device is electrically coupled to the battery cell in a series connection, and the series connection is electrically coupled between the positive terminal and the negative terminal. A sensor coupled to the battery system to detect electrical parameters on the secondary switching device and to provide sensor signals related to the electrical parameters; as well as A control system electrically coupled to the sensor, the primary switching device, and the secondary switching device, the control system being configured to perform diagnostics on the battery system, the diagnostics including: Determine the intended position of the primary switching device; Control the secondary switching device to close; Based on sensor signals related to the electrical parameters of the secondary switching device, the actual position of the primary switching device is determined; and Compare the expected position of the primary switching device with the actual position of the primary switching device.

32. The electrical system of claim 31, wherein when the primary switching device is closed, a first-order current is allowed to flow through the primary switching device, wherein when the secondary switching device is closed, a second-order current is allowed to flow through the secondary switching device, and wherein the first-order current is greater than the second-order current.

33. A method of operating an electrical system, the electrical system comprising: The battery system includes a positive terminal, a negative terminal, a battery cell, a primary switching device with an electromechanical switching mechanism, and a secondary switching device with a semiconductor switching mechanism. The secondary switching device is electrically coupled to the primary switching device in a parallel connection, the parallel connection of the primary switching device and the secondary switching device is electrically coupled to the battery cell in a series connection, and the series connection is electrically coupled between the positive terminal and the negative terminal. A voltage sensor, coupled to the battery system, is provided to detect a voltage drop across the secondary switching device and to provide a sensor signal related to the voltage drop. as well as The control system, electrically coupled to the voltage sensor, the primary switching device, and the secondary switching device, includes the following method: The secondary switching device is instructed to close to allow current to flow between the battery cell, the positive terminal, and the negative terminal. Determine the intended position of the primary switching device; During the closing of the secondary switching device, the actual position of the primary switching device is determined based on the voltage drop across the secondary switching device; and Whether the primary switching device is operating normally is determined based on the expected position and the actual position of the primary switching device.

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