Connection detection circuit for a charger integrated into a vehicle

Abstract

Vehicle power supply system (10), which includes: a high-voltage battery (14) that can be operated to output a current sufficient to power an electric motor (16) for propelling the vehicle, a low-voltage battery (24) that can be operated to output a current sufficient to power one or more vehicle subsystems (26), wherein the low-voltage battery (24) is not capable of outputting a current sufficient to power the electric motor (16), a low-voltage power supply device (30) that can be operated to regulate a current provided by the low-voltage battery (14) when it is in an active state, and cannot be operated to regulate a current provided by the low-voltage battery (14) when it is in a standby state, a vehicle-integrated charger (20) that can be operated to charge the high-voltage battery (14) with a current supplied via a connected connecting cable (22), wherein the integrated charger (20) requires a regulated current from the low-voltage power supply unit (30) to detect the connection of the connecting cable (22), and a connection detection circuit (36) that can be operated to switch the low-voltage power supply device (30) from the standby state to the active state when the connecting cable (22) is connected to the integrated charger (20), characterized in that the connection detection circuit (36) comprises a wake-up circuit (40) which can be operated to generate a wake-up voltage using a current from the low-voltage battery (24), wherein the wake-up voltage is sufficient to bring the low-voltage power supply device (30) from the sleep state to the active state, wherein the connecting cable (22) forms part of the wake-up circuit (40) when it is connected to a socket of the integrated charger (20), and the wake-up circuit (40) can be operated to transition from an open circuit state to a closed circuit state when the connecting cable (22) is connected to the socket, wherein the wake-up circuit (40) can be operated to generate the wake-up voltage when it is in the closed circuit state, and cannot be operated to generate the wake-up voltage when it is in the open circuit state, and wherein The wake-up circuit (40) stops drawing current for generating the wake-up voltage as soon as the low-voltage power supply unit (30) has transitioned from the standby state to the active state.

Description

[0001] The present invention relates to a connection detection circuit that can be used in conjunction with a vehicle-integrated charger to detect a connection to a power cable or other element used for charging the vehicle.

[0002] A vehicle-mounted charger can be used to charge a high-voltage battery in an electric or hybrid vehicle and supply power to an electrically powered motor. Charging can be accomplished using a connector cable or other element that can supply power from an electrical outlet or charging station to the vehicle-mounted charger. The connector cable can include an adapter for connection to a receptacle associated with the vehicle-mounted charger. The vehicle-mounted charger can include electronic or other elements for controlling and managing the flow of power to the high-voltage battery and for other charging operations.

[0003] The document DE 195 03 310 A1 discloses a mains charger for electric vehicles, which has a high-voltage part and a control device controlling it.

[0004] The document DE 197 15 880 C1 discloses a system of wired control units with reduced quiescent current requirements.

[0005] The document Lazzaro, Volker: “Charging systems for electric vehicles”, Mennekes Elektrotechnik GmbH & Co. KG, 10.02.2009 discloses a charging system for electric vehicles in which communication begins when the connector is plugged into the vehicle and into the power supply.

[0006] The document US 2010 / 0 079 105 A1 discloses a control system for charging on-board power storage devices for driving vehicles, as well as a control device and a method for determining the cable connection state.

[0007] The object of the invention is to provide an improved vehicle power supply system for detecting the connection of a connection cable to the vehicle.

[0008] This object is achieved by a vehicle power supply system having the features of claim 1 or by a connection detection circuit for use with a power supply device having the features of claim 9, or a method for activating an inactive power supply device having the features of claim 15.

[0009] Various features of the invention will become apparent from the following detailed description with reference to the accompanying drawings. Fig. 1 shows a vehicle power supply system according to a non-limiting aspect of the present invention. Fig. Figure 2 shows a proximity detection circuit according to a non-limiting aspect of the present invention. Fig. 3 shows a low voltage power supply circuit according to a non-limiting aspect of the present invention.

[0010] Fig. 1 schematically illustrates the logical elements associated with a vehicle power system 10 according to one non-limiting aspect of the present invention. The vehicle power system 10 will be described with reference to an electric vehicle, a hybrid vehicle, or other vehicle 12 having a high-voltage battery 14 or other power source for providing sufficient power to propel the vehicle 12 through an electric motor 16. The vehicle 12 may include an on-board charger 20 for charging the high-voltage battery 14 with power supplied via a power cable 22, wherein the power cable 22 is used to connect the on-board charger to an electrical outlet or charging station (not shown).The connecting cable 22 supplies power via a connector (not shown) provided at one end of the connecting cable 22 to be received in a socket (not shown) associated with the integrated charger 20.

[0011] The integrated charger 20 may include electronic or other elements operable to control and manage the flow of power for operations to charge the high-voltage battery 14, and optionally further charge or otherwise power a low-voltage battery 24, one or more vehicle subsystems 26, and / or other electronically operated elements within the vehicle 12. The low-voltage battery 24 may be provided to power vehicle systems 26 that operate at lower voltages than the electric motor 16, such as remote locking systems, heating and cooling systems, infotainment systems, braking systems, etc. In addition to charging via the connector cable 22, the high- and low-voltage batteries 14, 24, and / or the vehicle subsystems 26 may also power each other or be powered by power generated by the electric motor 16.

[0012] For example, the low-voltage battery 24 may be operated to provide sufficient current for use by a low-voltage power supply 30. The low-voltage power supply 30 may be operated to regulate the current from the low-voltage battery 24 for use in the vehicle subsystems 26 and / or the on-board charger 20. A controller 32 may be included to facilitate the execution of logical operations and meet other processing requirements of the vehicle 12 (optionally, one or more of the elements may include their own controllers or processors).Here, "low voltage" and "high voltage" refer to voltage levels of approximately 5 VDC or 12 VDC, on the one hand, and voltage levels of approximately 200 VDC, on the other hand, which are commonly used in vehicles to support the operation associated with each of the respective power sources. However, the scope of the invention is not limited thereto. Power sources with the same or different voltage levels and / or power generation capacities may be used in accordance with the invention.

[0013] According to one non-limiting aspect of the present invention, the low-voltage power supply 30 is operable to use a voltage used by the integrated charger 20 for testing the connection of the connecting cable 22. The low-voltage source 30 may, for example, be a voltage or current regulator capable of compensating for voltage variations of the low- and / or high-voltage batteries 14, 24 and providing a stable current to the integrated charger 20 and / or another electrically connected element that may be sensitive to voltage variations.The low-voltage power supply device 30 can be operated in a sleep state when not in use to prevent power from the low-voltage battery 24 from being consumed, and can continue to be operated in an active state when power is to be supplied and the voltage from the low-voltage battery 24 is to be regulated.

[0014] According to one non-limiting aspect of the present invention, power consumption may be reduced while the on-board charger 20 is not needed (e.g., while the vehicle is not in use, the power cable is disconnected, etc.). The power saving may be achieved, according to one non-limiting aspect of the present invention, by the low-voltage power supply 30 entering the sleep state when operation of the on-board charger 20 is not needed and then transitioning from the sleep state to the active state when the on-board charger 20 is needed.

[0015] A proximity detection circuit 36 ​​may be included according to one non-limiting aspect of the present invention to provide a power-saving configuration that can be used to detect a connection of the power cable 22 to the integrated charger 20 during the sleep state of the low-voltage power supply 30. The proximity detection circuit 36 ​​can be operated to transition the low-voltage power supply 30 from the sleep state to the active state, consuming less than 50-100 µA. Once the low-voltage power supply 30 has been activated by the proximity detection circuit 36, the electronics of the integrated charger 20 can be used to detect a proper connection of the power cable.

[0016] Fig. Figure 2 schematically shows the proximity detection circuit 36 ​​according to a non-limiting aspect of the present invention. The proximity detection circuit 36 ​​includes the Fig. 2 shown circuit elements (switches, resistors, capacitors, diodes, etc.), whereby these circuit elements do not necessarily have to be part of a dedicated circuit. Instead, the circuit elements can be part of one or more of the circuit elements shown in Fig. 1, for example, some or all of the circuit elements shown may be included in the integrated charger 20, the low-voltage power supply 30, the vehicle subsystems 26, the controller 32, and / or the motor 26, etc. Several circuit elements are shown to achieve certain results, but the present invention may also use other circuit elements, and in particular other power-saving elements, to achieve similar results.

[0017] When the connecting cable 22 is connected to the integrated charger 20, the circuit 36 ​​is configured such that the connecting cable 22 forms part of the proximity detection circuit 36 ​​shown with the switch S1. For example, if the connecting cable 22 has a three-prong connection, an electrical connection can be established between nodes A and B of the switch S1 via the positive and negative terminals (the ground terminal can be grounded to the chassis). In this way, the connecting cable 22 can be considered part of the proximity detection circuit 36 ​​when plugged into the socket connected to the integrated charger 22.

[0018] A lock or other actuator (not shown) may be provided to secure the lead wire 22 in the receptacle or to allow other user actuation by which the connection of the lead wire can be detected. A switch S3 may be actuated from a normally open position to a closed position when the actuator is closed. As explained in more detail below, resistors R3 and R4 may be included to induce specific voltages depending on whether switch S3 is closed and shorting resistor R4. The elements involved in connecting the lead wire to the receptacle and the actuator may be considered an interconnection circuit portion 38 of the proximity sensing circuit.

[0019] Once the connector cable is connected, a voltage is provided between pin 3 and pin 4 that is proportional to a voltage provided across the connector cable 22. The integrated charger 20 may include connectors or other devices that manipulate or otherwise manage the voltage between pin 3 and pin 4 to charge the high-voltage battery 14. Although not shown, the integrated charger 20 may include a number of such circuit elements to accomplish charging the high-voltage battery 14. In addition to the circuit elements used for charge transfer from the connector cable 22 to the high-voltage battery 14, additional circuit elements and electronic elements (not shown) may also be included for sensing a connection of the connector cable 22.

[0020] Proper connection of the connecting cable 22 can be determined by the corresponding electronics of the integrated charger measuring a voltage across resistor R1 (detection logic is shown). The low-voltage power supply 30 can be configured to provide a 5V reference voltage used throughout the proximity detection circuitry, such that the voltage across resistor R1 has a first voltage set by resistor R2 and MOSFETs M1 and M3 when the connecting cable 22 is unconnected, and a larger second voltage set by the connecting cable 22, resistor R1, and MOSFET M1 when the connecting cable 22 is connected. The integrated charger 20 can determine proper connection of the connecting cable 22 based on whether the first or second voltage is detected.

[0021] According to one non-limiting aspect of the present invention, the power consumption of the low-voltage power supply 30 and the integrated charger 20 can be reduced by maintaining the low-voltage power supply 30 in the idle state whenever possible. While the low-voltage power supply 30 is in the idle state, the integrated charger 20, depending on its configuration, may not be able to detect a connection of the connecting cable 22 because the integrated charger 20 requires the 5V voltage provided by the low-voltage power supply 30 to test the first and second voltages as described above (i.e., to enable operation of the MOSFET m1). Fig.3 shows a circuit configuration for the low-voltage power supply device according to a non-limiting aspect of the present invention, in which a wake-up voltage is provided to an integrated circuit associated with the operation of the low-voltage power supply device.

[0022] The proximity detection circuit 36 ​​may include a wake-up circuit 40 operable to transition the low-voltage power supply from the sleep state to the active state in response to a wake-up voltage set by resistor R1. The wake-up voltage may be generated immediately after the connecting cable is connected (the closing of switch S1), with the wake-up circuit transitioning from an open circuit state to a closed circuit state when a current path is closed from a 12V input of the low-voltage battery via switch Q3, resistor R11, MOSFET M2, resistor R2, resistor R3, and resistor R4.

[0023] The wake-up voltage becomes available as soon as switch Q3 is activated, thereby creating a voltage divider between resistors R14 and R15, which in turn sets the wake-up voltage. Once the wake-up voltage is received by the low-voltage power supply 30, it transitions from the idle state to the active state and begins generating the 5V voltage for MOSFETs M1 and M3.

[0024] The power supply, in turn, activates switch Q5, which then deactivates switch Q2 and MOSFET M2. Deactivation of MOSFET M2 activates MOSFET M3 to provide the voltage drop across resistor R1, which is used to detect the connection of the connecting cable by the electronic elements of the integrated charger 20. Thereafter, the low-voltage power supply 30 remains in the active mode until the connecting cable 22 is removed and the corresponding voltage change across resistor R1 is detected, at which time the low-voltage source 30 transitions to the sleep mode in response to signals (not shown) from the integrated charger 20, the controller 32, or another suitable element.

[0025] As previously mentioned, the present invention can reduce the power consumption of a low-voltage power supply used to provide a test voltage used in conjunction with the electronic elements of an on-board charger or other test element to detect a voltage value associated with a connection status of a connector cable or other element used to electrically connect a vehicle-integrated charger to a charging station or other element remote from the vehicle. The subject circuitry can utilize a bipolar current mirror in series with a charger wiring configuration for waking an on-board charger for a hybrid vehicle or electric vehicle with a plug-in connector.The circuitry allows for low quiescent current draw from the battery, and the charging coupling connector can be used to complete the circuit for waking the integrated charger's power supply. The circuitry then reassigns itself to the proximity detection circuit after waking. The circuitry can be comprised entirely of hardware components, allowing the wake-up voltage to be generated without requiring a processor to issue instructions or generate signals in accordance with stored code. (If a processor is required to place the low-voltage source into a sleep mode, the present invention can wake the dormant low-voltage processor without requiring any processor operations.)

Claims

[1] Vehicle power supply system (10) comprising: a high-voltage battery (14) operable to output a current sufficient to power an electric motor (16) for driving the vehicle, a low-voltage battery (24) operable to output a current sufficient to power one or more vehicle subsystems (26), wherein the low-voltage battery (24) is incapable of outputting a current sufficient to power the electric motor (16), a low-voltage power supply device (30) operable to regulate a current provided by the low-voltage battery (14) when in an active state and inoperable to regulate a current provided by the low-voltage battery (14) when in a rest state, a vehicle-integrated charger (20) operable to charge the high-voltage battery (14) with a current provided via a connected connecting cable (22), the integrated charger (20) requiring a regulated current from the low-voltage power supply (30) to detect the connection of the connecting cable (22), and a connection detection circuit (36) operable to switch the low-voltage power supply device (30) from the idle state to the active state when the connecting cable (22) is connected to the integrated charger (20), characterized bythat the connection detection circuit (36) comprises a wake-up circuit (40) operable to generate a wake-up voltage using a current from the low-voltage battery (24), the wake-up voltage being sufficient to switch the low-voltage power supply device (30) from the idle state to the active state, wherein the connecting cable (22) forms part of the wake-up circuit (40) when it is connected to a socket of the integrated charger (20), and the wake-up circuit (40) is operable to transition from an open circuit state to a closed circuit state when the connecting cable (22) is connected to the socket, wherein the wake-up circuit (40) is operable to generate the wake-up voltage when it is in the closed circuit state and cannot be operated to generate the wake-up voltage when it is in the open circuit state, and wherein the wake-up circuit (40) stops consuming current for generating the wake-up voltage as soon as the low-voltage power supply device (30) has transitioned from the idle state to the active state. [2] Vehicle power supply system (10) according to claim 1, characterized by that the connection detection circuit (36) can determine a connection of the connecting cable (22) without consuming a quiescent current of more than 100 µA. [3] Vehicle power supply system (10) according to one of the preceding claims, characterized by in that the connection detection circuit (36) includes a connection circuit (38) operable to detect a connection of the connecting cable (22) depending on whether a voltage drop across a resistor (R1) connected to the low-voltage power supply device (30) is greater than a voltage threshold value. [4] Vehicle power supply system (10) according to claim 3, characterized by that the connecting circuit (38) can be operated to detect the closing of an actuator for blocking the connecting cable (22) on the integrated charger (20) in dependence on the voltage drop across the resistor (R1). [5] A connection detection circuit (36) for use with a power supply device (30) which must transition from a sleep state to an active state in order to supply a voltage required by an integrated charger (20) to test the connection with a connecting cable (22), the connection detection circuit (36) comprising: a connection circuit (38) which is formed in part by the connection cable (22) when it is connected to the integrated charger (20), and a wake-up circuit (40) operable to generate a wake-up voltage sufficient to switch the power supply device (30) from the idle state to the active state when the connecting cable (22) is connected to the integrated charger (20), characterized by , that the wake-up circuit (40) generates the wake-up voltage without using a processor to move the power supply device (30) from the idle state to the active state. [6] Connection detection circuit (36) according to claim 5, characterized by that the wake-up circuit (40) generates the wake-up voltage without consuming a current of more than 100 µA when the connecting cable (22) is not connected to the integrated charger (20). [7] Connection detection circuit (36) according to one of claims 5 or 6, characterized by that the wake-up circuit (40) generates the wake-up voltage when the connecting cable (22) indirectly closes a current path which connects a resistor (R15) in series with a low-voltage vehicle battery (24). [8] Connection detection circuit (36) according to one of claims 5 to 7, further characterized bya first resistor (R1) connected in series with the power supply device (30) and the connecting cable (22), and a measuring node used by the integrated charger (20) to test a connection of the connecting cable (22) based on a voltage drop across the first resistor (R1). [9] Connection detection circuit (36) according to claim 8, further characterized by a control circuit operable to connect a second resistor (R4) in series with the first resistor (R1) and the connecting cable (22) when a control switch (S3) is open, and to bypass the second resistor (R4) when the control switch (S3) is closed. [10] Connection detection circuit (36) according to claim 9, further characterized bya first switch (M1) connected in series with the first resistor (R1), the connecting cable (22) and the second resistor (R4), the first switch (M1) preventing current flow through the first resistor (R1) when the power supply device (30) is in the idle state. [11] A method for activating an inactive power supply device (30) used to supply a test voltage required by an integrated charger (20) to test a connection with a connecting cable (22), the method comprising the following steps: Detecting the connection of the connecting cable (22), and Activating the inactive power supply device to an active state after a connection of the connecting cable (22) has been detected and before the test voltage is provided, characterized by , that the inactive power supply device (30) can be activated without commands being issued by a processor and without the need for a clock signal. [12] Method according to claim 11, characterized by that the inactive power supply device is activated by a wake-up voltage from a wake-up circuit (40). [13] Method according to claim 12, characterized by that the connection of the connecting cable (22) is detected without the wake-up circuit (40) consuming a current of more than 100 µA while the connecting cable (22) is not connected. [14] Method according to one of claims 11 to 13, characterized by that the power supply device (30) is activated from the inactive state in which the power supply device (30) does not consume power, and then consumes power in the active state.

Images