High voltage component protection during vehicle recharging

Abstract

A protection system for a high voltage component includes a switching circuit and a protection controller. The switching circuit changes a variable arrangement of a plurality of battery packs between a parallel arrangement and a series arrangement. The protection controller commands the switching circuit to enter the series arrangement in response to a recharge session, commands a current flow in the recharge session, measures a measurement voltage between an input node of the high voltage component and a floating chassis ground, advances a timer when the measurement voltage indicates a presence of an inappropriate voltage, and cancels the recharge session in response to the presence of the inappropriate voltage for greater than an exposure time. The recharge session provides a direct current fast charge voltage to the battery packs in the series arrangement, and the direct current fast charge voltage is greater than a battery voltage.

Description

Technical Field

[0001] This disclosure relates to systems and methods for protecting high-voltage components during vehicle recharging. Background Technology

[0002] Many electrical systems in electric vehicles operate at the same high voltage specified for the vehicle's battery pack. Sometimes a recharge voltage higher than the battery pack's high voltage is used to shorten recharge time. This recharge voltage can be applied to the electrical systems due to fault conditions. Fault conditions can include isolation losses and resistive short circuits. For example, a fault in one electrical system can couple the recharge voltage to other electrical systems via a common chassis connection that is otherwise isolated from each other by high impedance. Faults can generate undesirable chassis currents and / or overvoltages, which, if exposed to prolonged accumulation times, can cause irreversible hardware degradation. Therefore, those skilled in the art continue to conduct research and development in the field of high-voltage component protection during electric vehicle recharging. Summary of the Invention

[0003] This document provides a protection system for a high-voltage component. The protection system includes a switching circuit and a protection controller. The switching circuit is coupled to multiple battery packs and the high-voltage component. The switching circuit is configured to change the variable arrangement of the multiple battery packs between a parallel arrangement and a series arrangement, and to transfer electrical power from the multiple battery packs to the high-voltage component. Each of the multiple battery packs operates at its battery voltage. The high-voltage component operates at its battery voltage. The high-voltage component includes an input node and a floating chassis ground. The protection controller is coupled to the switching circuit and the high-voltage component. The protection controller is configured to: command the switching circuit to enter a series arrangement in response to a first recharge session; command a first flow of a first current during the first recharge session; measure a measured voltage between the input node of the high-voltage component and the floating chassis ground during the first recharge session; advance a timer when the measured voltage indicates an inappropriate voltage between the input node and the floating chassis ground; and cancel the first recharge session in response to the presence of an inappropriate voltage greater than the exposure time. The first recharge session provides a first DC fast-charging voltage to the multiple battery packs arranged in series. The first DC fast-charging voltage is greater than the battery voltage.

[0004] In one or more embodiments of the protection system, the protection controller is also configured to command the switching circuitry into a parallel arrangement after the first recharge session has been cancelled, and to maintain the parallel arrangement of the multiple battery packs as long as the protection system has been moved less than a threshold distance since the first recharge session was cancelled due to inappropriate voltage.

[0005] In one or more embodiments of the protection system, the protection controller is also configured to enable a series arrangement of multiple battery packs in response to the protection system being moved greater than a threshold distance since the first recharge session was canceled due to inappropriate voltage.

[0006] In one or more embodiments of the protection system, the protection controller is further configured to command current flow in a second recharge session when multiple battery packs are arranged in parallel. The second recharge session provides a second DC fast charging voltage to the multiple battery packs arranged in parallel. The second DC fast charging voltage is substantially matched to the battery voltage.

[0007] In one or more embodiments of the protection system, the protection controller is also configured to disable the series arrangement of multiple battery packs in response to a timer exceeding its accumulated time.

[0008] In one or more embodiments, the protection system includes a maintenance port coupled to a protection controller and configured to receive a notification that maintenance has been performed on a high-voltage component. The protection controller is also configured to enable a series arrangement of multiple battery packs in response to the notification.

[0009] In one or more embodiments of the protection system, the cumulative time is approximately 600 seconds, and the exposure time is approximately 5 seconds.

[0010] In one or more embodiments of the protection system, the input nodes of the high-voltage component include positive and negative input nodes. The measured voltages include a positive measured voltage between the positive input node and the floating chassis ground, and a negative measured voltage between the negative input node and the floating chassis ground. The protection controller determines the presence of inappropriate voltages based on one or more of the positive and negative measured voltages.

[0011] In one or more embodiments of the protection system, the battery voltage is approximately 400 volts, and the first DC fast charging voltage is approximately 800 volts.

[0012] This document provides a method for fault detection during vehicle recharging. The method includes: changing a variable arrangement of multiple battery packs of the vehicle from a parallel arrangement to a series arrangement in response to a first recharging session. Each of the multiple battery packs operates at its battery voltage. The method includes: transferring electrical power from the multiple battery packs to a high-voltage component of the vehicle. The high-voltage component operates at its battery voltage and includes an input node and a floating chassis ground. The method further includes: commanding a first flow of a first current during the first recharging session using a protection controller of the vehicle. The first recharging session provides a first DC fast-charging voltage to the series-arranged multiple battery packs. The first DC fast-charging voltage is greater than the battery voltage. The method includes: measuring a measured voltage between the input node of the high-voltage component and the floating chassis ground during the first recharging session; advancing a timer when the measured voltage indicates an inappropriate voltage between the input node of the high-voltage component and the floating chassis ground; and canceling the first recharging session in response to the presence of an inappropriate voltage at the high-voltage component exceeding an exposure time.

[0013] In one or more embodiments, the method includes: rearranging a plurality of battery packs into a parallel arrangement after a first recharge session has been cancelled; and maintaining the parallel arrangement of the plurality of battery packs while the vehicle has been driven less than a threshold distance since the first recharge session was cancelled due to inappropriate voltage.

[0014] In one or more embodiments, the method includes: enabling a series arrangement of multiple battery packs in response to the vehicle being driven for a distance greater than a threshold distance since a first recharge session was canceled due to inappropriate voltage.

[0015] In one or more embodiments, the method includes: commanding a second flow of a second current during a second recharge session when multiple battery packs are arranged in parallel. The second recharge session provides a second DC fast charging voltage to the multiple battery packs arranged in parallel. The second DC fast charging voltage is substantially matched to the battery voltage.

[0016] In one or more embodiments, the method includes disabling the series arrangement of multiple battery packs in response to a timer exceeding an accumulated time.

[0017] In one or more embodiments, the method includes: enabling a series arrangement of multiple battery packs in response to a notification that maintenance has been performed on the vehicle.

[0018] In one or more embodiments of the method, the cumulative time is approximately 600 seconds and the exposure time is approximately 5 seconds.

[0019] This document provides a vehicle. The vehicle includes multiple battery packs, a high-voltage component, a switching circuit, and a protection controller. Each of the multiple battery packs operates at the battery voltage. The high-voltage component has an input node and a floating chassis ground. The high-voltage component operates at the battery voltage. The switching circuit is coupled to the multiple battery packs and the high-voltage component, and is coupled to a charging station. The switching circuit is configured to change the variable arrangement of the multiple battery packs between a parallel arrangement and a series arrangement, and to transfer electrical power from the multiple battery packs to the high-voltage component. The protection controller is coupled to the switching circuit and the high-voltage component, and is coupled to the charging station. The protection controller is configured to: command the switching circuit to enter a series arrangement in response to a recharging session; command current flow from the charging station during the recharging session; measure the voltage between the input node of the high-voltage component and the floating chassis ground during the recharging session; advance a timer when the measured voltage indicates an inappropriate voltage between the input node of the high-voltage component and the floating chassis ground; and cancel the recharging session in response to the presence of an inappropriate voltage exceeding the exposure time.

[0020] In one or more embodiments of the vehicle, the input nodes of the high-voltage component include a positive input node and a negative input node. The measured voltage includes a positive measured voltage between the positive input node and the floating chassis ground, and a negative measured voltage between the negative input node and the floating chassis ground. The presence of inappropriate voltages is based on one or more of the positive and negative measured voltages.

[0021] In one or more embodiments, the vehicle includes a sensor configured to measure the vehicle's speed. The protection controller is also configured to: disable the series arrangement of multiple battery packs in response to the speed being less than a threshold speed since a recharge session was canceled due to inappropriate voltage; and enable the series arrangement of multiple battery packs in response to the speed being greater than a threshold speed since a recharge session was canceled due to inappropriate voltage.

[0022] The present invention may also include the following solutions.

[0023] 1. A protection system for high-voltage components, comprising:

[0024] A switching circuit, capable of coupling to multiple battery packs and the high-voltage component, is configured as follows:

[0025] The variable arrangement of the multiple battery packs can be changed between parallel and series arrangements; and

[0026] Electrical power is transferred from the plurality of battery packs to the high-voltage component, wherein each of the plurality of battery packs operates at the battery voltage, the high-voltage component operates at the battery voltage, and the high-voltage component includes an input node and a floating chassis ground; and

[0027] A protection controller, coupled to the switching circuit and the high-voltage component, is configured to:

[0028] In response to the first recharge session, the switching circuit is commanded to enter a series arrangement;

[0029] Command the first flow of the first current in the first recharge session;

[0030] During the first recharge session, the measured voltage between the input node of the high-voltage component and the floating chassis ground is measured;

[0031] When the measured voltage indicates an inappropriate voltage between the input node and the floating chassis ground, the timer is advanced; and

[0032] The first recharge session is cancelled in response to the presence of an inappropriate voltage greater than the exposure time, wherein the first recharge session provides a first DC fast charging voltage to the plurality of battery packs arranged in series, and the first DC fast charging voltage is greater than the battery voltage.

[0033] 2. The protection system according to Scheme 1, wherein the protection controller is further configured as follows:

[0034] After the first charging session has been cancelled, the switching circuit is commanded to enter a parallel arrangement; and

[0035] The parallel arrangement of the plurality of battery packs is maintained when the protection system has moved less than a threshold distance since the first recharge session was canceled due to the inappropriate voltage.

[0036] 3. The protection system according to Scheme 2, wherein the protection controller is further configured to enable the series arrangement of the plurality of battery packs in response to the protection system moving a distance greater than the threshold since the first recharge session was canceled due to the inappropriate voltage.

[0037] 4. The protection system according to Scheme 3, wherein the protection controller is further configured to command current flow in a second recharge session when the plurality of battery packs are arranged in parallel, the second recharge session providing a second DC fast charging voltage to the plurality of battery packs arranged in parallel, and the second DC fast charging voltage being substantially matched with the battery voltage.

[0038] 5. The protection system according to claim 1, wherein the protection controller is further configured to disable the series arrangement of the plurality of battery packs in response to the timer exceeding the accumulated time.

[0039] 6. The protection system according to claim 5 further includes a maintenance port coupled to the protection controller and configured to receive a notification that maintenance has been performed on the high-voltage component, wherein the protection controller is further configured to enable the series arrangement of the plurality of battery packs in response to the notification.

[0040] 7. The protection system according to claim 5, wherein the cumulative time is approximately 600 seconds and the exposure time is approximately 5 seconds.

[0041] 8. The protection system according to Scheme 1, wherein:

[0042] The input node of the high-voltage component includes a positive input node and a negative input node;

[0043] The measured voltage includes the positive measured voltage between the positive input node and the floating chassis ground, and the negative measured voltage between the negative input node and the floating chassis ground; and

[0044] The protection controller determines the presence of an inappropriate voltage based on one or more of the positive and negative measured voltages.

[0045] 9. The protection system according to claim 1, wherein the battery voltage is approximately 400 volts and the first DC fast charging voltage is approximately 800 volts.

[0046] 10. A method for fault detection during vehicle recharging, comprising:

[0047] In response to a first recharge session, the variable arrangement of the vehicle’s multiple battery packs is changed from a parallel arrangement to a series arrangement, wherein each of the multiple battery packs operates at the battery voltage.

[0048] Electrical power is transferred from the plurality of battery packs to the high-voltage components of the vehicle, wherein the high-voltage components operate at the battery voltage and include an input node and a floating chassis ground.

[0049] The vehicle's protection controller commands a first flow of a first current during the first recharge session, wherein the first recharge session provides a first DC fast charging voltage to the plurality of battery packs arranged in series, and the first DC fast charging voltage is greater than the battery voltage.

[0050] During the first recharge session, the measured voltage between the input node of the high-voltage component and the floating chassis ground is measured;

[0051] The timer is advanced when the measured voltage indicates an inappropriate voltage between the input node of the high-voltage component and the floating chassis ground; and

[0052] In response to the presence of an inappropriate voltage at the high-voltage component exceeding the exposure time, the first recharge session is cancelled.

[0053] 11. The method according to Scheme 10 further includes:

[0054] The parallel arrangement of the plurality of battery packs is maintained when the vehicle has been driven less than a threshold distance since the first recharge session was canceled due to the inappropriate voltage.

[0055] 12. The method according to Scheme 11 further includes:

[0056] In response to the vehicle being driven for a distance greater than the threshold distance since the first recharge session was canceled due to the inappropriate voltage, the series arrangement of the plurality of battery packs is enabled.

[0057] 13. The method according to Scheme 12 further includes:

[0058] When the plurality of battery packs are arranged in parallel, a second flow of a second current is commanded in a second recharge session, wherein the second recharge session provides a second DC fast charging voltage to the plurality of battery packs arranged in parallel, and the second DC fast charging voltage is substantially matched to the battery voltage.

[0059] 14. The method according to Scheme 10 further includes:

[0060] In response to the timer exceeding the accumulated time, the series arrangement of the plurality of battery packs is disabled.

[0061] 15. The method according to Scheme 14 further includes:

[0062] In response to a notification that maintenance has been performed on the vehicle, the series arrangement of the plurality of battery packs is enabled.

[0063] 16. The method according to Scheme 14, wherein the cumulative time is approximately 600 seconds and the exposure time is approximately 5 seconds.

[0064] 17. A vehicle comprising:

[0065] Multiple battery packs, each operating at battery voltage;

[0066] A high-voltage component having an input node and a floating chassis grounded, and operating at the battery voltage;

[0067] A switching circuit, coupled to the plurality of battery packs and the high-voltage component, capable of being coupled to a charging station, and configured to:

[0068] The variable arrangement of the multiple battery packs can be changed between parallel and series arrangements; and

[0069] Transmitting electrical power from the plurality of battery packs to the high-voltage component; and

[0070] A protection controller, coupled to the switching circuit and the high-voltage component, capable of being coupled to the charging station, and configured to:

[0071] In response to a recharge session, the switching circuit is commanded to enter a series arrangement;

[0072] Command the flow of current from the charging station during the recharging session;

[0073] Measure the voltage between the input node of the high-voltage component and the floating chassis ground during the recharge session;

[0074] The timer is advanced when the measured voltage indicates an inappropriate voltage between the input node of the high-voltage component and the floating chassis ground; and

[0075] In response to the presence of an inappropriate voltage exceeding the exposure time, the recharge session is cancelled.

[0076] 18. The vehicle according to Scheme 17, wherein:

[0077] The input node of the high-voltage component includes a positive input node and a negative input node;

[0078] The measured voltage includes the positive measured voltage between the positive input node and the floating chassis ground, and the negative measured voltage between the negative input node and the floating chassis ground; and

[0079] The presence of an inappropriate voltage is based on one or more of a positive and a negative measured voltage.

[0080] 19. The vehicle according to claim 17 further includes:

[0081] A sensor configured to measure the speed of the vehicle; and

[0082] The protection controller is further configured as follows:

[0083] In response to the speed being less than a threshold speed since the recharging session was canceled due to the inappropriate voltage, the series arrangement of the plurality of battery packs is disabled; and

[0084] In response to the speed exceeding a threshold speed since the recharge session was canceled due to the inappropriate voltage, the series arrangement of the multiple battery packs is enabled.

[0085] 20. The vehicle according to claim 17, wherein the protection controller is further configured to:

[0086] In response to the timer exceeding the accumulated time, the series arrangement of the plurality of battery packs is disabled; and

[0087] In response to a notification that maintenance has been performed on the vehicle, the series arrangement of the plurality of battery packs is enabled.

[0088] In one or more embodiments of the vehicle, the protection controller is further configured to: disable the series arrangement of the multiple battery packs in response to a timer exceeding an accumulated time; and enable the series arrangement of the multiple battery packs in response to a notification that maintenance has been performed on the vehicle. The foregoing features and advantages, as well as other features and advantages of this disclosure, will become apparent from the following detailed description of the best mode for carrying out this disclosure, taken in conjunction with the accompanying drawings. Attached Figure Description

[0089] Figure 1 It is a schematic plan view of a system according to one or more exemplary embodiments.

[0090] Figure 2 This is a schematic diagram of a protection system in a first ultra-high voltage configuration according to one or more exemplary embodiments.

[0091] Figure 3 This is a schematic diagram of a protection system in a second ultra-high voltage configuration according to one or more exemplary embodiments.

[0092] Figure 4 This is a schematic diagram of a protection system in a high-voltage configuration according to one or more exemplary embodiments.

[0093] Figure 5 This is a schematic diagram of a protection controller according to one or more exemplary embodiments.

[0094] Figure 6 This is a schematic diagram of a switching circuit according to one or more exemplary embodiments.

[0095] Figure 7 This is a schematic diagram of the interface between a charging station, a switching circuit, and a vehicle controller according to one or more exemplary embodiments.

[0096] Figure 8 This is a flowchart of a method for recharging preparation according to one or more exemplary embodiments.

[0097] Figure 9 This is a flowchart of a method for a first recharging session according to one or more exemplary embodiments.

[0098] Figure 10 This is a flowchart of a method for a second recharging session according to one or more exemplary embodiments. Detailed Implementation

[0099] Various embodiments of this disclosure generally provide a system and / or method for protecting high-voltage components in a vehicle from isolation faults, wherein the high-voltage (HV) architecture includes recharge capability under ultra-high voltage (EHV) conditions achieved by connecting multiple battery packs in series. When an ultra-high voltage (e.g., 800 Vdc) is applied to a high-voltage component (e.g., 400 Vdc) between the high-voltage rail and the chassis during recharging, the system / method senses the excessive voltage, measures the cumulative exposure time of the excessive voltage, and takes corrective action if the excessive voltage does not diminish. If the cumulative exposure time exceeds a short limit, the system / method may terminate the recharging session and disable ultra-high voltage recharging. Ultra-high voltage recharging may be re-enabled if the vehicle has moved at least a certain distance and / or traveled at a speed above a certain speed after leaving the charging station. The re-enabled feature typically extends the vehicle's ultra-high voltage recharging capability by taking into account transient fault isolation issues. If the cumulative exposure time of the high-voltage component becomes too long, the system / method may disable future ultra-high voltage recharging sessions until maintenance has been performed.

[0100] Implementations of the system / method can provide recharging at multiple different voltage levels. In various embodiments, the vehicle battery pack can be recharged at the battery pack's conventional high voltage level. Therefore, the vehicle can be recharged at an ultra-high voltage charging station when there are very few or no fault isolation issues. Once a detected fault poses a threat to high-voltage components, or if an ultra-high voltage charging station is unavailable, the vehicle can be recharged at a conventional high-voltage charging station.

[0101] refer to Figure 1 A schematic plan view of an exemplary embodiment of system 80 is shown according to one or more exemplary embodiments. System 80 generally includes a charging station 90 and a vehicle 100 having a protection system 110. The protection system 110 includes a switching circuit 112 and a protection controller 114. Vehicle 100 also includes a maintenance port 116, sensors 118, multiple battery packs 130a-130n, a high-voltage component 140, and a driver controller 150.

[0102] Charging station 90 and protection controller 114 communicate bidirectionally via control pilot signals (CPS). The control pilot signals are used to sense, initiate, control, and terminate recharging sessions between charging station 90 and vehicle 100. During a recharging session, charging station 90 can provide vehicle 100 with a recharging voltage (Vc) and a recharging current (Ic). The recharging voltage Vc can range from approximately 270 Vdc to approximately 1600 Vdc. The recharging current Ic can range from approximately 6 amps to approximately 100 amps.

[0103] The protection controller 114 can generate a switching control signal (SC) that is transmitted to the switching circuit 112. The switching control signal SC can transmit various commands to control the arrangement of the battery packs 130a-130n. The switching control signal SC can also transmit information used by the switching circuit 112 to notify of the end of a recharging session with the charging station 90. The maintenance port 116 can be coupled to an external test device and presents a notification signal (N) from that external test device to the protection controller 114. The notification signal N typically notifies the protection controller 114 that a previously disabled overvoltage recharging session can be enabled.

[0104] A distance / speed signal (DS) is generated by sensor 118 and transmitted to protection controller 114. The distance / speed signal DS can carry data about how far and / or how fast the vehicle 100 has moved. A recharge selection signal (RCS) can be generated by driver controller 150 and received by protection controller 114. The recharge selection signal RCS carries a command from the driver indicating what voltage level of recharge will occur (e.g., high voltage recharge, extra-high voltage recharge, or another voltage level recharge). Switching circuit 112 can provide electrical power (PWR) to high-voltage component 140. Electrical power PWR can be presented as the conventional battery voltage of battery packs 130a-130n.

[0105] Charging station 90 is implemented as a DC fast charging (DCFS) station. In some embodiments, charging station 90 is operable to provide a recharge voltage Vc at a high voltage level (e.g., approximately 400 Vdc). In other embodiments, charging station 90 is operable to provide a recharge voltage Vc at an ultra-high voltage level (e.g., approximately 800 Vdc). Other recharge voltages Vc can be implemented to meet the design criteria of a particular application.

[0106] The charging station 90 is also operable to communicate with the protection controller 114 via a control pilot signal CPS. In various embodiments, the charging station 90 may conform to the SAE International J1772 standard and / or the International Electrotechnical Commission (IEC) 61851-1 standard. The charging station 90 may be a DC level 1 and / or DC level 2 charger. Other charging standards may be implemented to meet the design requirements of specific applications. Some charging stations 90 may be placed in a fixed location. Other charging stations 90 may be mobile, for example, mounted on a flatbed truck.

[0107] Vehicle 100 is implemented as an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. In various embodiments, electric vehicle 100 may conform to SAE International J1772 standard and / or International Electrotechnical Commission (IEC) 61851-1 standard. Electric vehicle 100 may implement DC level 1 and / or DC level 2 charging capabilities. Other standards may be implemented to meet the design requirements of specific applications. In various embodiments, electric vehicle 100 may include, but is not limited to, buses, trucks, autonomous vehicles, motorcycles, boats, and / or aircraft. In some embodiments, electric vehicle 100 may be a stationary object, such as a room, compartment, and / or stationary structure. Other types of electric vehicle 100 may be implemented to meet the design requirements of specific applications.

[0108] Protection system 110 is implemented as a fault isolation protection system. Protection system 110 is operable to change the variable arrangement of battery packs 130a-130n between parallel and series arrangements in response to one or more fault detections. The arrangement selection is based on the voltage level used in the current recharge session. When battery packs 130a-130n are in parallel or series arrangement, protection system 110 transfers recharge power from charging station 90 to battery packs 130a-130n. When battery packs 130a-130n are in parallel or series arrangement, protection system 110 also transfers electrical power PWR from battery packs 130a-130n to high-voltage component 140. During the recharge session, one or more voltages are measured between corresponding one or more input nodes of high-voltage component 140 and the floating chassis ground of high-voltage component 140. When the measured voltage indicates an inappropriate voltage between the input node and the floating chassis ground, a timer is advanced. In response to the presence of an inappropriate voltage at a high-voltage component exceeding the exposure time, the recharge session is terminated, and battery packs 130a-130n are configured in parallel arrangement.

[0109] Switching circuit 112 is implemented as a high-power switch and a controller capable of communicating with charging station 90. Switching circuit 112 is operable to selectively arrange battery packs 130a-130n in parallel or series configuration. In parallel configuration, each battery pack 130a-130n contributes to the electrical power PWR supplied to high-voltage component 140, and each battery pack 130a-130n is recharged by a portion of the recharge current Ic. In series configuration, at least one of battery packs 130a-130n provides the electrical power PWR supplied to high-voltage component 140, and the battery pack 130a-130n is recharged by the full recharge current Ic. Switching circuit 112 is also operable to communicate with charging station 90 via control pilot signal CPS. The control pilot signal CPS can be used to notify the charging station 90 that the vehicle 100 is in standby mode waiting for a recharging session, that the vehicle 100 exists and is connected, that the recharging session should start, that the recharging session should start with ventilation, that the recharging session should end, and that an error has been detected.

[0110] The protection controller 114 is implemented as a computer configured to protect the high-voltage component 140 from overvoltage during a recharging session. For an overvoltage recharging session, the protection controller 114 is operable to command the switching circuit 112 to configure the battery packs 130a-130n in series, command the charging station 90 to provide electrical power to recharge the battery packs 130a-130n, and sense the measured voltage between the floating chassis ground of the high-voltage component 140 and one or more of the input nodes during the recharging session. When the measured voltage indicates an inappropriate voltage between the input node and the floating chassis ground, the protection controller 114 can advance a timer, cancel the recharging session with the charging station 90 in response to the presence of an inappropriate voltage exceeding the exposure time or the battery packs 130a-130n having been recharged, and command the switching circuit 112 to configure the battery packs 130a-130n in parallel after the recharging session has ended.

[0111] For a high-voltage recharge session, the protection controller 114 is operable to command the switching circuit 112 to configure the battery packs 130a-130n in parallel, command the charging station 90 to generate the flow of recharge current Ic in another recharge session, and terminate the recharge session in response to the battery packs 130a-130n being recharged.

[0112] Maintenance port 116 is implemented as a connector accessible to maintenance personnel. Maintenance port 116 is operable to transmit a notification signal N from a test device (not shown) to a protection controller 114.

[0113] Sensor 118 is implemented as a distance sensor and / or a speed sensor. For distance, sensor 118 is operable to measure the distance traveled by vehicle 100. For speed, sensor 118 is operable to measure the current speed of vehicle 100. Distance and / or speed can be reported to protection controller 114 via distance / speed signal DS.

[0114] Each battery pack 130a-130n is implemented as a rechargeable energy storage system. During recharging, battery packs 130a-130n can receive electrical power from charging station 90. During both recharging and discharging, battery packs 130a-130n can supply electrical power to high-voltage component 140. Each battery pack 130a-130n operates at a battery voltage Vb (see...). Figure 2 Operation. In various embodiments, battery packs 130a-130n can be implemented as two groups, such that when the two groups are arranged in series, the ultra-high voltage can be 2Vb. Each group can contain one or more battery packs 130a-130n connected in parallel within that group. In some embodiments, battery packs 130a-130n can be implemented as three groups, such that when the three groups are arranged in series, the ultra-high voltage can be 3Vb. Other numbers of groups can be implemented to meet the design criteria of a particular application.

[0115] High-voltage component 140 is implemented as one or more circuits in vehicle 100 that operate at battery voltage. High-voltage component 140 may include, but is not limited to, electric motors and pumps. Other high-voltage components 140 may be implemented to meet design criteria for specific applications.

[0116] The driver controller 150 functions as a human-machine interface actuator and indicator. The driver controller 150 is operable to receive input from the vehicle driver and present information to the driver. One of the inputs includes a selection of the recharge voltage Vc to be used for recharging the battery packs 130a-130n. The selected recharge voltage (e.g., 400 Vdc or 800 Vdc) can be provided to the protection controller 114 in the recharge selection signal RCS. The driver controller 150 is also operable to present an error indication to the driver if overvoltage recharge is selected while overvoltage recharge is disabled.

[0117] Typically, the protection system 110 prevents the high-voltage component 140 from being exposed to excessively high voltages exceeding several hundred volts (e.g., approximately 450V) from the positive high-voltage rail to vehicle ground and from the negative high-voltage rail to vehicle ground for more than a few seconds (e.g., 1-10 seconds) during a single exposure and for more than the cumulative time (e.g., 550-650 seconds) during the lifetime of the high-voltage component 140. During ultra-high voltage DC fast charging operation, if the protection system 110 detects an excessively positive high voltage to vehicle ground and / or an excessively negative high voltage to vehicle ground at the high-voltage component 140 exceeding the exposure voltage for more than the exposure time limit, it causes the timer to advance and the series arrangement of battery packs 130a-130n is disabled. Thereafter, the protection system 110 allows battery packs 130a-130n to be arranged in parallel, rather than in series, until the speed of vehicle 100 exceeds a predetermined speed (e.g., approximately 5 km / h) and / or vehicle 100 has traveled a predetermined distance (e.g., approximately 50 meters). When the accumulation time exceeding the exposure voltage exceeds the accumulation time, the series arrangement of battery packs 130a-130n is disabled, and a fault latch is set in the protection controller 114. The series arrangement of battery packs 130a-130n and thus recharging under ultra-high voltage are disabled (or blocked) until the damaged high-voltage component 140 has been replaced by maintenance and the fault latch has been cleared by applying a notification signal N.

[0118] Table I provides example rates of isolated faults by model year for existing manufacturing of electric vehicles, as follows:

[0119] Table I

[0120] Total quantity 78000 Year Unique Vehicle Identification Number (VIN) Number of occurrences Average per VIN 2017 115 1852 16.10 2018 118 720 6.10 2019 208 1579 7.59 2202 37 778 21.03 2021 7 377 53.86

[0121] refer to Figure 2 The diagram illustrates an exemplary embodiment of a protection system 110 in a first ultra-high voltage configuration, according to one or more exemplary embodiments. The charging station 90 generally includes a station controller 92 and a plug 94. The protection controller 114 includes a vehicle controller 122. A socket 120 is coupled to the plug 94 to provide bidirectional communication via a control pilot signal CPS and to recharge battery packs 130a to 130n during a first recharging session using a first recharging current Ic1. The first recharging current Ic1 may be a charging current Ic( Figure 1 A variant of ).

[0122] The charging station 90 can present the recharging power as a positive first DC fast charging voltage Vc1p coupled to one end of the series arrangement and a negative first DC fast charging voltage Vc1n coupled to the opposite end of the series arrangement. The resulting recharging voltage can be referred to as the first DC fast charging voltage Vc1, or simply the first recharging voltage Vc1. The first recharging voltage Vc1 can be the recharging voltage Vc( Figure 1 A variant of ).

[0123] Switching circuit 112 is configured to arrange battery packs 130a-130n in series. Each battery pack 130a-130n may have a positive terminal 132 and a negative terminal 134. Each battery pack 130a-130n operates at battery voltage Vb. The end battery pack (e.g., 130n) in the series arrangement of battery packs 130a-130n can provide electrical power PWR to high-voltage component 140. In this way, high-voltage component 140 can receive electrical power while battery packs 130a-130n are being recharged.

[0124] The high-voltage component 140 generally includes a positive input node 142, a negative input node 144, and a floating chassis ground 146. The positive input node 142 and negative input node 144 are coupled across the final battery pack 130n. The floating chassis ground 146 is coupled to the vehicle frame 100 and is grounded to the ground via the tires. A positive fault isolation path IFp may exist between the positive first DC fast charging voltage Vc1p and the chassis of the high-voltage component 140 (e.g., the floating chassis ground 146).

[0125] Protection controller 114 is coupled to the positive input node 142, negative input node 144, and floating chassis ground 146 of high-voltage component 140. Protection controller 114 is operable to measure the positive measured voltage Vp between positive input node 142 and floating chassis ground 146. Protection controller 114 is also operable to measure the negative measured voltage Vn between negative input node 144 and floating chassis ground 146. One or both of the positive measured voltage Vp and the negative measured voltage Vn can determine the presence of a positive fault isolation IFp, and if present, the extent of the fault. Vehicle controller 122 communicates with station controller 92 via control pilot signal CPS.

[0126] Under normal conditions (e.g., no isolation fault), the internal resistance of the high-voltage component 140 can present a similar impedance between the floating chassis ground 146 and each of the positive input node 142 and negative input node 144. Thus, the positive measurement voltage Vp and the negative measurement voltage Vn relative to the floating chassis ground 146 should be approximately half of the battery voltage Vb (e.g., 400 Vdc) (e.g., +200 Vdc and -200 Vdc, respectively). When a positive isolation fault is present, the positive first DC fast-charging voltage Vc1p is pulled down towards the floating chassis ground 146 of the high-voltage component 140. The extent of the pull is based on the impedance of the positive isolation fault IFp. This pull reduces the positive measurement voltage Vp and increases the negative measurement voltage Vn. For example, if the positive fault isolation IFp is short-circuited, the positive measured voltage Vp relative to the floating chassis ground 146 will be -400 Vdc due to the battery pack 130a, and the negative measured voltage Vn relative to the floating chassis ground 146 will be -800 Vdc due to the series arrangement of the battery packs 130a-130n.

[0127] Once the negative measured voltage Vn falls below the overvoltage threshold (e.g., a drop of 250 volts from -200 Vdc to -450 Vdc) and / or the positive measured voltage Vp drops to a similar voltage (e.g., a drop of 250 volts from +200 Vdc to -50 Vdc), the protection controller 114 can infer that the positive isolation fault IFp is substantial and activates an internal timer. If the positive isolation fault IFp persists for at least the exposure time, the protection controller 114 can signal the station controller 92 via the vehicle controller 122 to terminate the first charging session.

[0128] refer to Figure 3 The diagram illustrates an exemplary embodiment of the protection system 110 in a second ultra-high voltage configuration, according to one or more exemplary embodiments. Figure 3 The circuit and voltage shown are similar to Figure 2 The circuit and voltage shown differ in that the high-voltage component 140 is coupled to the top battery pack 130a, and the negative isolation fault IFn can exist between the negative first DC fast charging voltage Vc1n and the floating chassis ground 146.

[0129] As before in the absence of an isolation fault, the positive measurement voltage Vp and the negative measurement voltage Vn relative to the floating chassis ground 146 should be approximately half of the battery voltage Vb (e.g., 400 Vdc) (e.g., +200 Vdc and -200 Vdc, respectively). When a negative isolation fault is present, the negative first DC fast-charging voltage Vc1n is pulled up towards the floating chassis ground 146 of the high-voltage component 140. The extent of the pull is based on the impedance of the negative isolation fault IFn. This pull increases the positive measurement voltage Vp and decreases the negative measurement voltage Vn. For example, if the negative fault isolation IFn is short-circuited, the positive measurement voltage Vp will be +800 Vdc relative to the floating chassis ground 146 due to the battery packs 130a-130n, and the negative measurement voltage Vn will be +400 Vdc relative to the floating chassis ground 146 due to the battery pack 130n.

[0130] Once the positive measured voltage Vp exceeds an excessive voltage (e.g., an increase of 250 volts from +200 Vdc to +450 Vdc) and / or the negative measured voltage Vn increases by a similar voltage (e.g., an increase of 250 volts from -200 Vdc to +50 Vdc), the protection controller 114 can infer that the negative isolation fault IFp is substantial and activate an internal timer. If the negative isolation fault IFn persists for at least the exposure time, the protection controller 114 can signal the station controller 92 via the vehicle controller 122 to terminate the first charging session.

[0131] refer to Figure 4 The diagram illustrates an exemplary embodiment of a protection system 110 in a high-voltage configuration, according to one or more exemplary embodiments. Figure 4 The circuit and voltage shown are similar to Figure 2 The circuit and voltage shown differ in that battery packs 130a-130n are arranged in parallel, and charging station 90 presents a second current Ic2 under a second DC fast charging voltage Vc2 (e.g., 400 Vdc). The second DC fast recharge voltage Vc2 can be simply referred to as the second recharge voltage Vc2. The second recharge voltage Vc2 can be a recharge voltage Vc ( Figure 1 A variation of ). The second recharge voltage Vc2 roughly matches the battery voltage Vb.

[0132] If either the positive second DC fast charging voltage Vc2p or the negative second DC fast charging voltage Vc2n is short-circuited to the floating chassis ground 146 of the high-voltage component 140, one of the positive measurement voltage Vp or the negative measurement voltage Vn will be driven to zero volts, and the other measurement voltage will be +400 Vdc or -400 Vdc relative to the floating chassis ground 146. In either case, the amplitude of the positive measurement voltage Vp and the negative measurement voltage Vn will not exceed an excessive voltage (e.g., 450 Vdc), and therefore will not pose a threat to the high-voltage component 140. Thus, the protection controller 114 will not stop the charging session, and the battery packs 130a-130n will continue to be recharged as planned.

[0133] refer to Figure 5 The diagram illustrates an exemplary embodiment of the protection controller 114 according to one or more exemplary embodiments. The protection controller 114 generally includes a reference voltage circuit 160, a positive sensor circuit 162a, a negative sensor circuit 162b, a summing circuit 164, a hardware overvoltage protection circuit 166, one or more processors 170 (one shown), a memory circuit 172, a timer 174, a positive rail isolation resistor Ria, a negative rail isolation resistor Rib, a positive rail sensing resistor Rsa, and a negative rail sensing resistor Rsb.

[0134] The reference voltage circuit 160 is implemented as a reference voltage generator. The reference voltage circuit 160 is operable to generate a low reference voltage (e.g., +2.5 Vdc) relative to the floating chassis ground 146.

[0135] The positive sensor circuit 162a is implemented as a voltage sensor. The positive sensor circuit 162a is operable to measure the voltage across the positive rail sensing resistor Rsa. The measured voltage, as a positive voltage value (VP), is provided to the processor 170 and the summing circuit 164. The positive voltage value VP is a proportion of the positive measured voltage Vp. This proportion is determined by the positive rail isolation resistor Ria and the positive rail sensing resistor Rsa.

[0136] The negative sensor circuit 162b is implemented as another voltage sensor. The negative sensor circuit 162b is operable to measure the voltage across the negative rail sensing resistor Rsb. The measured voltage, as a negative voltage value (VN), is provided to the processor 170 and the summing circuit 164. The negative voltage value VN is a proportion of the negative measured voltage Vn. This proportion is determined by the negative rail isolation resistor Rib and the negative rail sensing resistor Rsb.

[0137] The summing circuit 164 is implemented as an adder circuit. The summing circuit 164 is operable to add the positive voltage value VP and the negative voltage value VN to calculate the summed voltage value (VS). The summed voltage value VS is provided to the processor 170 and the hardware overvoltage protection circuit 166.

[0138] Hardware overvoltage protection circuit 166 is operable to determine the presence of an overvoltage (e.g., excessively high voltage) condition. When an overvoltage condition exists, hardware overvoltage protection circuit 166 is operable to present an overvoltage protection value (VOV) to processor 170 and assert an overvoltage safety signal (VOS). When no overvoltage condition exists, hardware overvoltage protection circuit 166 deactivates the overvoltage safety signal VOS. The overvoltage safety signal VOS can be used by other circuitry (not shown) to remove high-voltage power to prevent damage.

[0139] Processor 170 is implemented as one or more central processing units (CPUs). Processor 170 is operable to execute software. The software may be stored in a non-transitory computer-readable medium (e.g., non-volatile memory). When executed by processor 170, the software may cause processor 170 to monitor the positive measured voltage Vp and / or the negative measured voltage Vn, and take corrective action if either or both indicate an excessively high voltage that would indicate an isolation fault that cannot be ignored. When an isolation fault (e.g., IFp or IFn) poses a risk to high-voltage components 140, processor 170 may command vehicle controller 122 to notify station controller 92 in charging station 90 to terminate the recharging session.

[0140] Memory 172 is implemented as one or more memory circuits. Memory 172 is operable to store software and data used and / or generated by processor 170. Memory 172 may include non-transitory computer-readable media and volatile memory.

[0141] Timer 174 is implemented as a counter. When activated by processor 170, timer 174 accumulates (e.g., counts) time and reports the time back to processor 170. Timer 174 can be deactivated (e.g., stopped counting) under the control of processor 170. Timer 174 can also be reset by processor 170 to an initial (e.g., zero) count.

[0142] In various embodiments, timer 174 may be implemented as a single timer that reports the current accumulated time. Processor 170 may use the current accumulated time to determine when the exposure time limit has been reached and when the accumulation time limit has been reached. In other embodiments, timer 174 may be implemented as two timers. One timer may count the exposure time upon activation and subsequently report when the exposure time limit has been reached. The other timer may count the accumulated time upon activation and subsequently report when the exposure time limit has been reached. Other forms of timers may be implemented to meet the design criteria of a particular application.

[0143] Timer 174 allows for the measurement of multiple occurrences of fault exposure before the high-voltage component 140 is considered damaged by an isolated fault. For example, with an accumulation time limit set to 600 seconds and an exposure time limit of 5 seconds, the high-voltage component 140 may experience at least 120 fault exposures before the protection controller 114 blocks (or disables) the overvoltage recharge. Allowing multiple fault exposures can reduce potential warranty costs. To further reduce potential warranty costs, various embodiments may implement a separate timer for each of the multiple high-voltage components 140. Therefore, an over-isolation fault in one of the high-voltage components 140 will not simultaneously trigger repair / replacement of every high-voltage component 140.

[0144] refer to Figure 6 The diagram illustrates an exemplary embodiment of a switching circuit 112 according to one or more exemplary embodiments. The switching circuit 112 generally includes a pair of charging switches 180a-180b, a pair of parallel switches 182a-182b, and a series switch 184. The open / closed state of switches 180a to 184 is controlled by a switch control signal SC.

[0145] Charging switches 180a-180b can receive a positive DC fast charging voltage Vcp and a negative DC fast charging voltage Vcn from socket 120. When charging switches 180a-180b are open, switching circuit 112 disconnects battery packs 130a-130n and high-voltage component 140 from charging station 90. When charging switches 180a-180b are closed, electrical power from charging station 90 can be used to recharge battery packs 130a-130n.

[0146] Parallel switch 182a is arranged between the positive terminals 132 of battery packs 130a-130n, and parallel switch 182b is arranged between the negative terminals 134 of battery packs 130a-130n. When parallel switches 182a-182b are open, battery packs 130a-130n are electrically isolated from each other, thus allowing for series connection. When parallel switches 182a-182b are closed and series switch 184 is open, battery packs 130a-130n are electrically connected together in parallel.

[0147] A series switch 184 is disposed between the positive terminal 132 of battery pack 130n and the negative terminal 134 of battery pack 130a. When the series switch 184 is open, battery packs 130a-130n can be connected in parallel. When the series switch 184 is closed and the parallel switches 182a-182b are open, battery packs 130a-130n are arranged in series.

[0148] refer to Figure 7This diagram illustrates an exemplary embodiment of the interface between a charging station 90, a switching circuit 112, and a vehicle controller 122, according to one or more exemplary embodiments. When the plug 94 and socket 120 are engaged, the charging station 90 provides a charging current Ic through a pair of pins in the plug 94 and socket 120. A third pin in the plug 94 and socket 120 shares chassis ground. A fourth pin transmits a control pilot signal CPS between the station controller 92 and the vehicle controller 122. A proximity signal (PS) is generated by the vehicle controller 122 and provided to a proximity switch 96 in the plug 94 through a fifth pin in the plug 94 and socket 120. The proximity switch 96 is mechanically linked to a latch release actuator (not shown) on the plug 94. During recharging, the latch release actuator is released, and the proximity switch 96 closes. Therefore, the vehicle controller 122 sees a first load grounded to the chassis. When the latch release actuator is engaged, the proximity switch 96 opens, the vehicle controller 122 sees a different load grounded to the chassis, and sends a signal to the station controller 92 to stop the recharging session before disconnecting the power pin.

[0149] Reference Figure 8 The following flowchart illustrates an exemplary implementation of a method 200 for recharging preparation, according to one or more exemplary embodiments. Method (or process) 200 is implemented by system 80. Method 200 includes steps 202 to 214, as shown. The order of the steps is shown as a representative example. Other orderings of steps may be implemented to meet the standards of a particular application.

[0150] In step 202, prior to the start of the recharge session, switching circuit 112 configures battery packs 130a-130n in a parallel arrangement for normal operation. In step 204, protection controller 114 receives a recharge selection signal RCS from driver controller 150. If extra-high voltage (EHV) recharge (e.g., 800 Vdc) is selected, protection controller 114 determines in step 206 whether EHV recharge is enabled. If EHV recharge is selected but not enabled (disabled), an error signal is presented to the driver in step 208. Thereafter, in step 210, switching circuit 112 and protection controller 114 maintain battery packs 130a-130n in a parallel arrangement, and method 200 returns to step 202.

[0151] If ultra-high voltage recharging is selected and enabled, in step 212, the protection controller 114 commands the switching circuit 112 to configure battery packs 130a-130n in a series arrangement. During the transition to and within the series arrangement, in step 214, the switching circuit 112 transfers electrical power from at least one battery pack 130a-130n to the high-voltage component 140. If high-voltage (HV) recharging (e.g., 400 Vdc) is selected in step 204, in step 210, the switching circuit 112 and the protection controller 114 maintain battery packs 130a-130n in a parallel arrangement. Method 200 then returns to step 202, where electrical power is still supplied to the high-voltage component 140 by battery packs 130a-130n.

[0152] refer to Figure 9 The flowchart illustrates an exemplary implementation of a method 220 for a first recharge session, according to one or more exemplary embodiments. Method (or process) 220 may be implemented by system 80. The first recharge session of method 220 is an ultra-high voltage recharge. Method 220 includes steps 222 to 266, as shown. The order of the steps is shown as a representative example. Other orderings of steps may be implemented to meet the standards of a particular application.

[0153] In step 222, the protection system 110 waits for a signal from the charging station 90 indicating that the first recharging session under ultra-high voltage is ready. Once the charging station 90 is ready, the vehicle controller 122 commands the switching circuit 112 to close the charging switches 180a-180b, and in step 224 commands the charging station 90 to begin recharging. In step 226, the vehicle 100 receives the first recharging current Ic1.

[0154] In step 228, the protection controller 114 measures one or both of the measured voltages Vp and / or Vn between the input nodes 142 / 144 of the high-voltage component 140 and the floating chassis ground 146 during the first recharge session. In step 230, the protection controller 114 performs a check to determine if an inappropriate (overly high) voltage is detected. If no inappropriate voltage is detected, the timer 174 does not advance (e.g., stops counting), and in step 232, the continuation of recharge is checked. If recharge should continue, method 220 loops back to step 228 to continue monitoring the measured voltages Vp and / or Vn.

[0155] If the first recharging session should end in step 232, then in step 234, the vehicle controller 122 may signal the station controller 92 to end the first charging session. In step 236, the protection controller 114 commands the switching circuit to place the battery packs 130a-130n in a parallel arrangement and disconnect the recharging switches 180a-180b. Thereafter, the charging station 90 may be disconnected from the vehicle in step 238, and method 220 ends.

[0156] Once an inappropriate voltage is detected in step 230, and the measured voltages Vp and / or Vn indicate an inappropriate voltage between the input nodes 142 / 144 of the high-voltage component 140 and the floating chassis ground 146, the protection controller 114 may advance the timer 174 in step 240. If the time for sensing the inappropriate voltage in step 242 is less than an exposure threshold, method 220 returns to step 228 and continues to monitor the input voltages Vp and / or Vn. The exposure time threshold can be determined by the short-term overvoltage capability of the high-voltage component 140, which is typically used in power-up procedures.

[0157] In response to the detection of an inappropriate voltage exceeding the exposure time in step 242, in step 244, the protection controller 114 signals the vehicle controller 122 to instruct the station controller 92 to cancel the first recharge session. In response to the cancellation of the first recharge session due to the inappropriate voltage, in step 246, the protection controller 114 disables the series arrangement of battery packs 130a-130n. In step 248, the protection controller 114 further commands the switching circuit 112 to rearrange battery packs 130a-130n from a series arrangement to a parallel arrangement, and disconnects the recharge switches 180a-180b after the first recharge session has been cancelled.

[0158] In step 250, another time check is performed by the protection controller 114. If the high-voltage component 140 has been subjected to an inappropriate voltage for more than the cumulative time, then in step 252, the protection controller 114 disables the series arrangement. (In step 248, battery packs 130a-130n are pre-configured in a parallel arrangement.) In step 254, the protection controller 114 waits for notification via maintenance port 116 that an appropriate repair has been completed. If no notification is received, in step 256, the protection controller 114 and the switching circuit 112 maintain battery packs 130a-130n in a parallel arrangement. Once notification is received, the protection controller 114 enables the series arrangement in step 258. Method 220 then ends in step 260.

[0159] If the cumulative time limit has not been reached in step 250, in step 262, sensor 118 measures the distance and / or maximum speed that vehicle 100 has traveled (or moved) since the first recharge session was canceled due to inappropriate voltage. If the distance / speed traveled in step 254 is less than a threshold distance / threshold speed, in step 266, protection controller 114 and switching circuit 112 maintain battery packs 130a-130n in a parallel arrangement, and method 220 returns to step 262 to continue measuring the traveled distance. After the traveled distance / speed exceeds the threshold distance / threshold speed in step 264, protection controller 114 enables a series arrangement in step 258, and method 220 ends in step 260.

[0160] Disabling the over-voltage recharging function encourages the driver to move vehicle 100 away from a potentially faulty charging station 90. The driver should be notified to reactivate the over-voltage recharging function after the vehicle speed exceeds a threshold speed and / or the vehicle position has moved beyond a certain distance. Moving vehicle 100 away from a potentially faulty charging station 90 reduces the likelihood of high-voltage components 140 experiencing inappropriate voltage. The function of automatically activating high-voltage recharging in response to disabling and / or prohibiting over-voltage recharging generally provides convenience to the driver.

[0161] refer to Figure 10 The flowchart illustrates an exemplary implementation of a method 280 for a second recharging session according to one or more exemplary embodiments. Method (or process) 280 may be implemented by system 80. The second recharging session of method 280 is a high-voltage recharging. Method 280 includes steps 282 to 296, as shown. The order of the steps is shown as a representative example. Other orderings of steps may be implemented to meet the standards of a particular application.

[0162] In step 282, the protection system 110 waits for a signal from the charging station 90 indicating that the second recharging session under high voltage is ready. Once the charging station 90 is ready, the vehicle controller 122 commands the switching circuit 112 to close the recharging switches 180a-180b, and in step 284 commands the charging station 90 to begin recharging. The vehicle 100 receives the second recharging current Ic2 in step 286. The second recharging current Ic2 can be the recharging current Ic( Figure 1 A variant of ).

[0163] In step 288, a check can be performed to determine whether the second recharging session should continue. If the conclusion is to continue charging in step 290, method 280 can return to step 286, and vehicle 100 continues to receive the second recharging current Ic2. If the second recharging session should end, in step 292, vehicle controller 122 can signal to station controller 92 to end the second charging session. Protection controller 114 and switching circuit 112 maintain battery packs 130a-130n in parallel arrangement in step 294 and disconnect recharging switches 180a-180b. Thereafter, in step 296, charging station 90 can be disconnected from the vehicle, and method 280 ends.

[0164] Various embodiments sense different isolation faults, including isolation losses and resistive short circuits, by direct voltage sensing between the high-voltage rail (or input) and the chassis ground of the high-voltage component 140. The delay between sensing the overvoltage and taking protective action allows full utilization of the short-term overvoltage capability of the high-voltage component 140 to save cost, weight, and size. Direct voltage sensing does not rely on accurately measuring the isolation resistance of the connected electrical system, nor on measuring noisy ground fault currents to trigger protection.

[0165] Embodiments of system 80 generally provide machinery and / or methods for protecting high-voltage component 140 from isolation faults during ultra-high-voltage recharging. The protection generally includes: changing the variable arrangement of battery packs 130a-130n from a parallel arrangement to a series arrangement in preparation for a first recharging session, and transferring electrical power from battery packs 130a-130 to high-voltage component 140 in both arrangements. Once charging station 90 is ready, a first flow of a first recharging current Ic1 from charging station 90 to vehicle 100 is commanded during the first recharging session, and a measured voltage Vp and / or Vn is measured between input nodes 142 / 144 of high-voltage component 140 and floating chassis ground 146 during the first recharging session. When the measured voltage Vp / Vn indicates an inappropriate voltage between input nodes 142 / 144 and floating chassis ground 146, protection controller 114 advances timer 174. In response to the presence of an inappropriate voltage at high-voltage component 140 exceeding the exposure time, the first recharge session is cancelled, and after the first recharge session has been cancelled, the battery packs 130a-130n are rearranged from a series arrangement to a parallel arrangement.

[0166] All numerical values ​​of parameters (e.g., quantities or conditions) in this application (including the appended claims) should in all cases be understood to be modified by the term “about,” regardless of whether “about” actually appears before the numerical value. “About” indicates that the numerical value allows for some slight imprecision (a certain closeness to precision in numerical terms; approximately or reasonably close to the value; almost). If the imprecision provided by “about” cannot be understood in this ordinary sense in the art, then “about” as used herein at least indicates variations that may arise from common methods of measuring and using these parameters. Furthermore, the disclosure of ranges includes the disclosure of all values ​​and ranges further subdivided throughout the range. Each value within the range and the endpoints of the range are disclosed herein as separate embodiments.

[0167] While the best mode for carrying out this disclosure has been described in detail, those skilled in the art to which this disclosure pertains will recognize various alternative designs and embodiments for carrying out this disclosure within the scope of the appended claims.

Claims

1. A protection system for high-voltage components, comprising: A switching circuit, capable of coupling to multiple battery packs and the high-voltage component, is configured as follows: The variable arrangement of the multiple battery packs can be changed between parallel and series arrangements; as well as Electrical power is transferred from the plurality of battery packs to the high-voltage component, wherein each of the plurality of battery packs operates at the battery voltage, the high-voltage component operates at the battery voltage, and the high-voltage component includes an input node and a floating chassis ground; as well as A protection controller, coupled to the switching circuit and the high-voltage component, is configured to: In response to the first recharge session, the switching circuit is commanded to enter a series arrangement; Command the first flow of the first current in the first recharge session; During the first recharge session, the measured voltage between the input node of the high-voltage component and the floating chassis ground is measured; The timer advances when the measured voltage indicates an inappropriate voltage between the input node and the floating chassis ground. as well as The first recharge session is cancelled in response to the presence of an inappropriate voltage greater than the exposure time, wherein the first recharge session provides a first DC fast charging voltage to the plurality of battery packs arranged in series, and the first DC fast charging voltage is greater than the battery voltage.

2. The protection system according to claim 1, wherein, The protection controller is also configured to: After the first recharge session has been cancelled, the switching circuit is commanded to enter a parallel arrangement; and The parallel arrangement of the plurality of battery packs is maintained when the protection system has moved less than a threshold distance since the first recharge session was canceled due to the inappropriate voltage.

3. The protection system according to claim 2, wherein, The protection controller is also configured to enable the series arrangement of the plurality of battery packs in response to the protection system moving a distance greater than the threshold since the first recharge session was canceled due to the inappropriate voltage.

4. The protection system according to claim 3, wherein, The protection controller is also configured to command current flow in a second recharge session when the plurality of battery packs are arranged in parallel, the second recharge session providing a second DC fast charging voltage to the plurality of battery packs arranged in parallel, and the second DC fast charging voltage being matched with the battery voltage.

5. The protection system according to claim 1, wherein, The protection controller is also configured to disable the series arrangement of the plurality of battery packs in response to the timer exceeding the accumulated time.

6. The protection system of claim 5 further includes a maintenance port coupled to the protection controller and configured to receive a notification that maintenance has been performed on the high-voltage component, wherein the protection controller is further configured to enable the series arrangement of the plurality of battery packs in response to the notification.

7. The protection system of claim 5, wherein the cumulative time is 600 seconds and the exposure time is 5 seconds.

8. The protection system according to claim 1, wherein: The input node of the high-voltage component includes a positive input node and a negative input node; The measured voltage includes the positive measured voltage between the positive input node and the floating chassis ground, and the negative measured voltage between the negative input node and the floating chassis ground; as well as The protection controller determines the presence of an inappropriate voltage based on one or more of the positive and negative measured voltages.

9. The protection system according to claim 1, wherein, The battery voltage is 400 volts, and the first DC fast charging voltage is 800 volts.

10. A method for fault detection during vehicle recharging, comprising: In response to a first recharge session, the variable arrangement of the vehicle’s multiple battery packs is changed from a parallel arrangement to a series arrangement, wherein each of the multiple battery packs operates at the battery voltage. Electrical power is transferred from the plurality of battery packs to the high-voltage components of the vehicle, wherein the high-voltage components operate at the battery voltage and include an input node and a floating chassis ground. The vehicle's protection controller commands a first flow of a first current during the first recharge session, wherein the first recharge session provides a first DC fast charging voltage to the plurality of battery packs arranged in series, and the first DC fast charging voltage is greater than the battery voltage. During the first recharge session, the measured voltage between the input node of the high-voltage component and the floating chassis ground is measured; The timer is advanced when the measured voltage indicates an inappropriate voltage between the input node of the high-voltage component and the floating chassis ground; and In response to the presence of an inappropriate voltage at the high-voltage component exceeding the exposure time, the first recharge session is cancelled.

11. The method of claim 10, further comprising: The parallel arrangement of the plurality of battery packs is maintained when the vehicle has been driven less than a threshold distance since the first recharge session was canceled due to the inappropriate voltage.

12. The method of claim 11, further comprising: In response to the vehicle being driven for a distance greater than the threshold distance since the first recharge session was canceled due to the inappropriate voltage, the series arrangement of the plurality of battery packs is enabled.

13. The method of claim 12, further comprising: When the plurality of battery packs are arranged in parallel, a second flow of a second current is commanded in a second recharge session, wherein the second recharge session provides a second DC fast charging voltage to the plurality of battery packs arranged in parallel, and the second DC fast charging voltage matches the battery voltage.

14. The method of claim 10, further comprising: In response to the timer exceeding the accumulated time, the series arrangement of the plurality of battery packs is disabled.

15. The method of claim 14, further comprising: In response to a notification that maintenance has been performed on the vehicle, the series arrangement of the plurality of battery packs is enabled.

16. The method of claim 14, wherein the cumulative time is 600 seconds and the exposure time is 5 seconds.

17. A vehicle comprising: Multiple battery packs, each operating at battery voltage; A high-voltage component having an input node and a floating chassis grounded, and operating at the battery voltage; A switching circuit, coupled to the plurality of battery packs and the high-voltage component, capable of being coupled to a charging station, and configured to: The variable arrangement of the multiple battery packs can be changed between parallel and series arrangements; as well as Electrical power is transferred from the plurality of battery packs to the high-voltage component; as well as A protection controller, coupled to the switching circuit and the high-voltage component, capable of being coupled to the charging station, and configured to: In response to a recharge session, the switching circuit is commanded to enter a series arrangement; Command the flow of current from the charging station during the recharging session; Measure the voltage between the input node of the high-voltage component and the floating chassis ground during the recharge session; The timer advances when the measured voltage indicates an inappropriate voltage between the input node of the high-voltage component and the floating chassis ground. as well as In response to the presence of an inappropriate voltage exceeding the exposure time, the recharge session is cancelled.

18. The vehicle according to claim 17, wherein: The input node of the high-voltage component includes a positive input node and a negative input node; The measured voltage includes the positive measured voltage between the positive input node and the floating chassis ground, and the negative measured voltage between the negative input node and the floating chassis ground; as well as The presence of an inappropriate voltage is based on one or more of a positive and a negative measured voltage.

19. The vehicle according to claim 17, further comprising: A sensor configured to measure the speed of the vehicle; as well as The protection controller is further configured as follows: In response to the speed being less than a threshold speed since the recharge session was canceled due to the inappropriate voltage, the series arrangement of the multiple battery packs is disabled; as well as In response to the speed exceeding a threshold speed since the recharge session was canceled due to the inappropriate voltage, the series arrangement of the multiple battery packs is enabled.

20. The vehicle according to claim 17, wherein, The protection controller is also configured to: In response to the timer exceeding the accumulated time, the series arrangement of the plurality of battery packs is disabled; and In response to a notification that maintenance has been performed on the vehicle, the series arrangement of the plurality of battery packs is enabled.

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