Charging port contactor operation

Abstract

This disclosure provides "charging port contactor operation". A vehicle includes: a contactor electrically coupled between a charging port and a traction battery; and a controller configured to maintain the contactor in a closed position until a charging current estimate derived from vehicle load data is less than a predetermined threshold without sensing current through the contactor or receiving data about the current from a charging station. The maintenance of the contactor position is in response to a charging disconnection request.

Description

Technical Field

[0001] This disclosure relates to the operation of charging ports for vehicles. Background Technology

[0002] Electric vehicles can be plugged into a charging port to recharge their depleted energy storage devices. For example, a plug-in hybrid electric vehicle can be plugged into a charging station to recharge. While the vehicle is charging, current flows from the charging station to the vehicle. Disconnecting the vehicle from the charging station when a high current is flowing through the charging port can damage the contactor at the charging port. Summary of the Invention

[0003] A vehicle includes a contactor electrically connected between a charging port and a traction battery. The vehicle includes a controller configured to maintain the contactor in a closed position until an estimated charging current derived from vehicle load data is less than a predetermined threshold in the absence of sensing current through the contactor or receiving current data from a charging station. The contactor position is maintained in response to a charging disconnect request.

[0004] A method for a vehicle includes: in response to a charging disconnection request, a controller maintains a contactor electrically connected between a charging port of the vehicle and the vehicle's traction battery in a closed position until an estimated charging current derived from vehicle load data is less than a predetermined threshold in the absence of sensing current through the contactor or receiving data about the current from a charging station associated with the vehicle.

[0005] A vehicle includes a contactor electrically connected between a charging port and a traction battery. The vehicle includes a controller configured to open the contactor, thereby disabling power transfer between the traction battery and a charging station. The opening is in response to a charging disconnect request and a charging current estimate decreasing below a predetermined threshold derived from vehicle load data in the absence of sensed current through the contactor or data on current received from the charging station. Attached Figure Description

[0006] Figure 1 This is a system overview of plug-in vehicles;

[0007] Figure 2 This is an overview of the high-voltage systems in plug-in vehicles;

[0008] Figure 3 This is a functional block diagram of a learning feedback loop used for current estimation during battery charging.

[0009] Figure 4 This is a functional block diagram of the current estimation output after receiving a disconnection request; and

[0010] Figure 5 It is an algorithm used for the operation of the charging contactor. Detailed Implementation

[0011] This document describes embodiments of the present disclosure. However, it should be understood that the disclosed embodiments are merely examples, and other embodiments may take various forms and alternative forms. The drawings are not necessarily drawn to scale; some features may be exaggerated or minimized to show detail of particular components. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but merely as a representative basis for teaching those skilled in the art to employ the invention in different ways. As will be understood by those skilled in the art, various features shown and described with reference to any of the drawings may be combined with features shown in one or more other drawings to produce embodiments not explicitly shown or described. The combinations of features shown provide representative embodiments for typical applications. However, various combinations and modifications of features consistent with the teachings of this disclosure may be desired for a particular application or implementation.

[0012] When a vehicle is plugged in to connect to power and charge, the charging station can provide an indication of the current flowing between itself and the vehicle. During the disconnection procedure, the vehicle can open a contactor configured to receive current from the charging station to stop the flow of electricity. To open the contactor during the disconnection procedure, the vehicle may need to obtain or infer its own charging current value, as this information is not always available during the disconnection procedure. This means that the vehicle must use its own measurement or estimation of the charging current value to open the contactor, since the current value from the charging station is unavailable when the contactor disconnection procedure occurs. Instead of adding an additional current sensor to perform this measurement during disconnection, the vehicle can estimate the current flowing through the contactor after a disconnection request is made.

[0013] In practice, the vehicle controller can estimate the charging current by aggregating the vehicle's auxiliary loads and the current flowing from the traction battery, without directly measuring the charging current or receiving it from the charging station. The aggregation of auxiliary loads may include errors due to measurement uncertainties. Error compensation can be implemented using a feedback loop designed to compare the aggregated current estimate with a known current value from the charging station while the vehicle is charging. Learning algorithms can be used to improve the estimation accuracy during charging, allowing for a more accurate estimate to be used when a disconnection procedure occurs, thus preventing contactor welding or scarring, or delayed contactor opening.

[0014] Figure 1A block diagram 10 illustrates a vehicle 12 including one or more electric motors 14 mechanically connected to a hybrid transmission 16. The electric motors 14 may operate as either motors or generators. Furthermore, the hybrid transmission 16 may be mechanically connected to an engine 18. The hybrid transmission 16 may also be mechanically connected to a drive shaft 20, which is mechanically connected to wheels 22. When the engine 18 is on or off, the electric motors 14 can provide propulsion and deceleration capabilities. The electric motors 14 can also function as generators and can provide fuel economy benefits by recovering energy that would normally be lost as heat in friction braking systems. The electric motors 14 can also provide reduced pollutant emissions because, under certain conditions, the hybrid electric vehicle 12 can operate in either electric or hybrid mode to reduce the overall fuel consumption of the vehicle 12.

[0015] The traction battery (or battery pack) 24 stores and provides energy that can be used by the motor 14. The traction battery 24 can provide a high-voltage DC output from one or more battery cell arrays (sometimes referred to as battery cell stacks) within it. The battery cell array may include one or more battery cells. The traction battery 24 can be electrically connected to one or more power electronic device controllers 26 via one or more contactors (not shown). The one or more contactors isolate the traction battery 24 from other components when open and connect it to other components when closed.

[0016] The power electronics controller 26 can also be electrically connected to the motor 14 and can be configured to bidirectionally transfer electrical energy between the traction battery 24 and the motor 14. For example, the traction battery 24 can provide DC voltage, while the motor 14 may require three-phase AC voltage to operate. The power electronics controller 26 can convert the DC voltage to three-phase AC voltage according to the requirements of the motor 14. In regenerative mode, the power electronics controller 26 can convert the three-phase AC voltage from the motor 14, which acts as a generator, to the DC voltage required by the traction battery 24. The description herein also applies to pure electric vehicles. For pure electric vehicles, the hybrid transmission 16 can be a gearbox connected to the motor 14, and the engine 18 may be absent.

[0017] In addition to providing energy for propulsion, the traction battery 24 can also power other vehicle electrical systems. A DC / DC converter 28 can convert the high-voltage DC output of the traction battery 24 into a low-voltage DC power supply compatible with other vehicle loads. Other high-voltage loads (such as compressors and electric heaters) can be directly connected to the high voltage without using the DC / DC converter 28. Low-voltage systems can be electrically connected to the auxiliary battery 30 (e.g., a 12V battery).

[0018] The battery control module 33 can communicate with the traction battery 24. The battery controller 33 can be configured to monitor and manage the operation of the traction battery 24, such as via an electronic monitoring system (not shown) that manages the temperature and state of charge of each of the battery cells.

[0019] For example, vehicle 12 may be an electrified vehicle, which includes components for a plug-in hybrid electric vehicle (PHEV), a full hybrid electric vehicle (FHEV), a mild hybrid electric vehicle (MHEV), or a battery electric vehicle (BEV). Traction battery 24 may be recharged by an external power source 36. External power source 36 may be a connection to an electrical outlet. External power source 36 may be electrically connected to an electric vehicle power supply unit (EVSE) or a charging station 38. Charging station 38 may provide circuitry and controls for regulating and managing the transfer of electrical power between power source 36 and vehicle 12. External power source 36 may supply DC or AC power to charging station 38.

[0020] Charging station 38 may have a charging connector 40 for insertion into charging port 34 of vehicle 12. Charging port 34 may be any type of port configured to deliver power from charging station 38 to vehicle 12. Charging port 34 may be electrically connected to a charger or on-board power converter 32. Power converter 32 may regulate the power supplied from charging station 38 to provide appropriate voltage and current levels to traction battery 24. Power converter 32 may interface with charging station 38 to coordinate power delivery to vehicle 12. Charging station connector 40 may have a pin that mates with a corresponding recess in charging port 34.

[0021] refer to Figure 2 The diagram illustrates the electrical bus system of vehicle 12. When current is drawn from the charging station via charging port 34, battery control module 33 controls the flow of energy into and out of battery 24 via bus 150. Charging port 34 may include a digital communication gateway module (DCGM) 100 that communicates with charging station 16. DCGM 100 may be configured to receive signals indicating a request to transfer electrical energy between charging station 38 and battery pack 24 via an AC or DC charging session. In the case of AC charging, DCGM 100 may also communicate with BCCM 102. DCGM 100 communicates with the charging station via a medium for digital communication, which may be Wi-Fi, power line communication (PLC), controller area network (CAN), etc. Digital communication may include information about the current received from charging station 38.

[0022] Battery pack 24 may include one or more battery cells, a Bus Electrical Center (BEC) 104, and a Battery Energy Control Module (BECM) 33. BEC 104 may include a set of contactors 106 for connection to an inverter and a motor generator 114. BEC 104 may also include a set of charging contactors 180 having positive leads 152 and negative leads 154 for connecting the positive leads 164 and negative leads 162 of battery 24, as well as the positive leads 172 and negative leads 170 of the high-voltage bus, to a charging station 38. The high-voltage bus may include a PTC heater 110, an air conditioning compressor 112, and a motor generator 114. The high-voltage bus may also include a high-voltage to low-voltage converter 28 and other low-voltage loads 30. Each of these loads may be estimated or measured.

[0023] refer to Figure 3 The functional block diagram 200 is shown. Functional block diagram 200 includes logic for error correction. A high-voltage bus current estimate 202 is combined with a battery current measurement result 220 in functional block 222 to generate a charging current estimate 224 using a node analysis method. This means subtracting the battery current measurement result 220 from the high-voltage bus current estimate 202. Subtracting the actual charging current 230 from the charging station 38 from the charging current estimate 224 determines the actual error 234 of the charging current estimate. The high-voltage bus current estimate 202 is also fed into a learning algorithm 204 to derive an error estimate 208. Subtracting the actual error 234 from the error estimate 208 and feeding it into the learning algorithm 204 updates the error estimate based on the new error. Functional block diagram 200 is continuously run to learn the error estimation function 208 while the vehicle 12 is charging or while the vehicle 12 and charging station 38 are in charging mode. Functional block diagram 200 can be processed on any of the vehicle's controllers, including BECM 33, DGCM 100, BCCM 102, or other vehicle controllers. A disconnect request can be received in response to receiving a state of charge (SOC) full signal from BECM 33.

[0024] Upon receiving a disconnect request or before disconnection, the controller can use Figure 4Functional block diagram 300 ensures that the vehicle controller uses only vehicle-generated information during contactor 180 opening. Functional block diagram 300 includes a high-voltage bus current estimate 302. The high-voltage bus current estimate 302 is combined with a battery current measurement result 308 in functional block 310 to generate a charging current estimate 324 using a node analysis method. This means that the battery current measurement result 308 is subtracted from the high-voltage bus current estimate 302. The charging current estimate 324 is corrected by an error estimate 306. The error estimate 306 is a function of the high-voltage bus current estimate 302. A machine learning algorithm learns this function during vehicle charging and adapts it to the latest operating / environmental conditions of the vehicle. This means that the error estimate is not constant, as functional block 304 can include different error values ​​for different bus current estimates under different operating / environmental conditions.

[0025] refer to Figure 5 Algorithm 400 is shown. The algorithm begins in step 402. The algorithm can run during the charging process of the electric vehicle. This means that algorithm 400 can be activated when the vehicle begins charging. In step 404, the controller or controller group receives charging current information from the charging station. This means that the charging station sends the charging current information to the controller via charging port 34 or DCGM 100. In step 406, as... Figure 3 The error estimate 208 is updated as described in the description. Steps 404 and 406 continue until a charge disconnect request is received in step 408. In step 408, the controller receives a charge disconnect request from one of the other controllers based on the SOC of battery 24 or through user intervention.

[0026] If a disconnection request is received in step 408, the controller determines whether the estimated charging current 314, including the included error, is less than a predetermined threshold. The predetermined threshold can be set to the current rating of the charging contactor. For example, most circuit breakers have current ratings where repetitive operation is possible without excessive arcing, scouring, or melting of the contactor. The predetermined threshold can be based on other factors. In an alternative embodiment, the predetermined threshold can be adjusted using the error estimate 306 instead of the charging current estimate adjusted by the error estimate 306. Therefore, the contactor can be opened in step 412 without excessive arcing. In step 414, the algorithm terminates.

[0027] The terms used in this specification are descriptive and not limiting, and it should be understood that various changes may be made without departing from the spirit and scope of this disclosure. As previously described, features of various embodiments may be combined to form other embodiments of the invention that may not be explicitly described or shown. While various embodiments may have been described as providing advantages or preference over other embodiments or prior art implementations in terms of one or more desired characteristics, those skilled in the art will recognize that one or more features or characteristics may be compromised to achieve desired overall system properties, depending on the specific application and implementation. These properties may include, but are not limited to, cost, strength, durability, lifecycle cost, marketability, appearance, packaging, size, maintainability, weight, manufacturability, ease of assembly, etc. Therefore, embodiments described as less ideal than other embodiments or prior art implementations in terms of one or more characteristics are also within the scope of this disclosure and may be desirable for a particular application.

[0028] According to the present invention, a vehicle is provided, the vehicle having: a contactor electrically connected between a charging port and a traction battery; and a controller configured to maintain the contactor in a closed position in response to a charging disconnection request until an estimated charging current derived from vehicle load data is less than a predetermined threshold in the absence of sensing current through the contactor or receiving data about the current from a charging station.

[0029] According to one embodiment, the charging current estimate is further derived from the difference between the charging current reported by the charging station before the disconnection request and the charging current estimate before the disconnection request.

[0030] According to one embodiment, the charging current estimate also includes an error estimate and a feedback loop.

[0031] According to one embodiment, the error estimate is derived from a neural network.

[0032] According to one embodiment, the feedback loop is ignored in response to a disconnect request.

[0033] According to one embodiment, the predetermined threshold is equal to the current rating of the contactor.

[0034] According to one embodiment, the disconnection request is based on the state of charge of the traction battery.

[0035] According to one embodiment, the charging current estimate is based on the sum of load indications that draw power from the high-voltage bus associated with the charging port and the traction battery.

[0036] According to the present invention, a method for a vehicle includes: in response to a charging disconnection request, a controller maintains a contactor electrically connected between a charging port of the vehicle and a traction battery of the vehicle in a closed position until an estimated charging current derived from vehicle load data is less than a predetermined threshold in the absence of sensing current through the contactor or receiving data about the current from a charging station associated with the vehicle.

[0037] According to one embodiment, the charging current estimate is further derived from the difference between the charging current reported by the charging station before the disconnection request and the charging current estimate before the disconnection request.

[0038] According to one embodiment, the charging current estimate also includes an error estimate and a feedback loop.

[0039] According to one embodiment, the error estimate is derived from a neural network.

[0040] According to one embodiment, the predetermined threshold is equal to the current rating of the contactor.

[0041] According to one embodiment, the disconnection request is based on the state of charge of the traction battery.

[0042] According to one embodiment, the charging current estimate is based on the sum of the loads that draw power from the high-voltage bus associated with the charging port and the traction battery.

[0043] According to the present invention, a vehicle is provided, the vehicle having: a contactor electrically connected between a charging port and a traction battery; and a controller configured to open the contactor in response to a charging disconnection request and a charging current estimate decreasing to below a predetermined threshold derived from vehicle load data in the absence of sensing current through the contactor or receiving data about the current from a charging station, thereby disabling power transfer between the traction battery and the charging station.

[0044] According to one embodiment, the charging current estimate is further derived from the difference between the charging current reported by the charging station before the disconnection request and the charging current estimate before the disconnection request.

[0045] According to one embodiment, the charging current estimate also includes an error estimate and a feedback loop.

[0046] According to one embodiment, the disconnection request is based on the state of charge of the traction battery.

[0047] According to one embodiment, the charging current estimate is based on the sum of load indications that draw power from the high-voltage bus associated with the charging port and the traction battery.

Claims

1. A vehicle, the vehicle comprising: A contactor electrically connected between the charging port and the traction battery; as well as A controller configured to maintain the contactor in a closed position in response to a charging disconnection request until the estimated charging current derived from vehicle load data is less than a predetermined threshold, provided that no current through the contactor is sensed and no data about the current is received from the charging station.

2. The vehicle as claimed in claim 1, wherein, The estimated charging current is further derived from the difference between the charging current reported by the charging station prior to the disconnection request and the estimated charging current prior to the disconnection request.

3. The vehicle as claimed in claim 2, wherein, The charging current estimate also includes an error estimate and a feedback loop.

4. The vehicle as claimed in claim 3, wherein, The error estimate is derived from a neural network.

5. The vehicle as claimed in claim 3, wherein, The feedback loop is ignored in response to the disconnect request.

6. The vehicle as claimed in claim 1, wherein, The predetermined threshold is equal to the current rating of the contactor.

7. The vehicle as claimed in claim 1, wherein, The disconnection request is based on the state of charge of the traction battery.

8. The vehicle as claimed in claim 1, wherein, The estimated charging current is based on the sum of load indications that draw power from the high-voltage bus associated with the charging port and the traction battery.

9. A method for a vehicle, the method comprising: In response to a charging disconnection request, the controller maintains a contactor electrically connected between the vehicle's charging port and the vehicle's traction battery in a closed position until the estimated charging current derived from the vehicle's load data is less than a predetermined threshold, provided that no current is sensed through the contactor and no data about the current is received from the charging station associated with the vehicle.

10. The method of claim 9, wherein, The estimated charging current is further derived from the difference between the charging current reported by the charging station prior to the disconnection request and the estimated charging current prior to the disconnection request.

11. The method of claim 10, wherein, The charging current estimate also includes an error estimate and a feedback loop.

12. The method of claim 11, wherein, The error estimate is derived from a neural network.

13. The method of claim 9, wherein, The predetermined threshold is equal to the current rating of the contactor.

14. The method of claim 9, wherein, The disconnection request is based on the state of charge of the traction battery.

15. The method of claim 9, wherein, The estimated charging current is based on the sum of the loads that draw power from the high-voltage bus associated with the charging port and the traction battery.

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