VEHICLE-SIDE CHARGER WITH CONTROL PILOT WAKE-UP CIRCUIT AND VEHICLE WITH IT

Abstract

Vehicle-side charger (18) for an electric vehicle (12), comprising: a charging unit operable to receive power from an electric vehicle supply equipment (24), Electric Vehicle Supply Equipment or EVSE (24), for charging a traction battery (14) of the electric vehicle (12), a control device (36) operable in a sleep mode or a wake mode, wherein the control device (36) is configured in the wake mode to control the charging unit for charging the traction battery (14) with the energy from the EVSE (24), and a control pilot wake-up circuit (38) comprising a contact monitoring circuit (46), a first control pilot state change detection circuit (42), and a second control pilot state change detection circuit (44), such that the contact monitoring circuit (46) is common to the first control pilot state change detection circuit (42) and the second control pilot state change detection circuits (44), wherein the control pilot wake-up circuit (38) is configured to receive a control pilot signal from the EVSE (24), to detect a change in the current state of the control pilot signal while the controller (36) is in the sleep mode, and to generate a wake-up signal for waking the controller (36) in response to the current state of the control pilot signal changing to a first new state or a second new state, and wherein the first control pilot state change detection circuit (42) is configured todetect a change in the current state of the control pilot signal to the first new state, and the second control pilot state change detection circuit (44) is configured to detect a change in the current state of the control pilot signal to the second new state.

Description

TECHNICAL FIELD

[0001] The present invention relates to a control pilot wake-up circuit for waking up an on-board charger (OBC) of an electric vehicle. BACKGROUND

[0002] An electric vehicle's on-board charger (OBC) is used to charge the vehicle's traction battery. In one variation, the OBC converts power received from an electric vehicle supply equipment (EVSE) connected to the electrical grid to a direct current and charges the battery with the direct current. In another variation, the OBC allows the battery to be charged directly with power received from an EVSE.

[0003] DE 102013 210 061 A1 discloses an on-board battery charging system for a plug-in electric vehicle. It comprises a charging unit for charging a high-voltage battery and a control unit for controlling and directing a current flow used to support operations related to charging the high-voltage battery. The control unit can detect a connection between the on-board battery charging system and an electric vehicle supply device (EVSE) and is configured to enter a sleep mode if a control pilot signal from the EVSE is either absent or indicates a delayed charging mode.

[0004] DE 10 2012 220 379 A1 discloses a control pilot detection circuit operable with a control pilot signal provided by an EVSE (Electric Vehicle Supply Equipment EVSE) system to facilitate the issuance of a control pilot activation signal. The control pilot activation signal can be operated with a controller to facilitate control operations of a vehicle charging system, such as charging a high-voltage battery included in a vehicle.

[0005] CN 1 06 160 090 A, CN 1 10 450 654 A, and CN 2 07 664 689 U each disclose a wake-up circuit for chargers. The wake-up circuit wakes up the charger with the CP signal when a charging plug is connected.

[0006] US 2011 / 0 193 532 A1 discloses a control device and a control method for charging. The aim is to ensure that charging processes can be continued even in the event of irregularities or can be resumed and completed after a possible interruption. SUMMARY

[0007] An on-board charger (OBC) for an electric vehicle includes a charging unit, a controller, and a control pilot wake-up circuit. The charging unit is operable to receive power from an electric vehicle supply equipment (EVSE) for charging a traction battery of the electric vehicle. The controller can operate in a sleep mode or a wake-up mode. In the wake-up mode, the controller is configured to control the charging unit to charge the traction battery with power from the EVSE.The control pilot wake-up circuit is configured to receive a control pilot signal from the EVSE, detect a change in a current state of the control pilot signal while the controller is in the sleep mode, and generate a wake-up signal for waking the controller in response to the current state of the control pilot signal changing to a new state. The charging unit may include (i) a converter operable to convert the power received from the EVSE to a usable form for charging the traction battery, and (ii) a relay operable to transfer the power received from the EVSE directly to the traction battery.

[0008] In one or more embodiments, the control pilot wake-up circuit includes a first control pilot state change detection circuit usable for detecting a change in the current state of the control pilot signal to a first new state, and a second control pilot state change detection circuit usable for detecting a change in the current state of the control pilot signal to a second new state. The first and second control pilot state change detection circuits comprise similar electronic components. The control pilot wake-up circuit further includes a contact monitoring circuit common to the first and second control pilot state change detection circuits.

[0009] The electronic components of the first control pilot state change detection circuit include a first capacitor. The contact monitoring circuit is operable to periodically inject a current pulse to the first capacitor for charging the first capacitor. The electronic components of the first control pilot state change detection circuit are arranged such that the first capacitor is discharged upon receiving the current pulse while the current state of the control pilot signal remains unchanged, and is charged to a voltage greater than a threshold upon receiving one or more of the current pulses after the current state of the control pilot signal has changed from the current state to the first new state.The contact monitoring circuit is further operable to generate the wake-up signal for waking the control device in response to the voltage of the first capacitor becoming greater than the threshold value due to a change of the current state of the control pilot signal to the first new state.

[0010] The electronic components of the second control pilot state change detection circuit include a second capacitor. The contact monitoring circuit is operable to periodically inject a current pulse to the second capacitor for charging the second capacitor. The electronic components of the second control pilot state change detection circuit are arranged such that the second capacitor is discharged after receiving the current pulse while the current state of the control pilot signal remains unchanged, and is charged to a voltage greater than the threshold when receiving one or more of the current pulses after the current state of the control pilot signal has changed from the current state to the second new state.The contact monitoring circuit is further operable to generate the wake-up signal for waking the control device in response to the voltage of the second capacitor becoming greater than the threshold value due to a change of the current state of the control pilot signal to the second new state.

[0011] The first and second control pilot state change detection circuits are both usable for detecting a change of the current state of the control pilot signal to a third new state.

[0012] In one or more embodiments, the states of the control pilot signal include a state A in which a voltage of the control pilot signal is zero volts, a state B1 in which the voltage of the control pilot signal is a constant, positive value other than zero volts, and a state B2 in which the voltage of the control pilot signal is an alternating value other than zero volts. When the current state of the control pilot signal is state B1 or state B2, the first control pilot state change detection circuit is used to detect a state change of the control pilot signal from state B1 to state B2 or from state B2 to state B1. When the current state of the control pilot signal is state A or state B2, the second control pilot state change detection circuit is used to detect a state change of the control pilot signal from state A to state B2 or from state B2 to state A.When the current state of the control pilot signal is state A or state B1, the first control pilot state change detecting circuit or the second control pilot state change detecting circuit is used to detect a state change of the control pilot signal from state A to state B1 or from state B1 to state A.

[0013] In one or more embodiments, the states of the control pilot signal include a state A indicating that an EVSE cable is disconnected from the on-board charger, a state B1 indicating that the EVSE cable is connected to the on-board charger but the EVSE is not ready to charge, and a state B2 indicating that the EVSE cable is connected to the on-board charger and the EVSE is ready to charge. When the current state of the control pilot signal is state A, the second control pilot state change detection circuit is used to detect a state change of the control pilot signal from state A to state B2, thereby waking the controller when the EVSE cable is connected to the on-board charger and the EVSE is ready to charge.

[0014] When the current state of the control pilot signal is state A, the first control pilot state change detection circuit or the second control pilot state change detection circuit is used to detect a state change of the control pilot signal from state A to state B1, thereby waking the controller when the cable of the EVSE is connected to the vehicle-side charger and the EVSE is not ready for charging.

[0015] When the current state of the control pilot signal is state B1, the first control pilot state change detection circuit is used to detect a state change of the control pilot signal from state B1 to state B2, thereby waking the controller when the cable of the EVSE is connected to the vehicle-side charger and the EVSE is ready for charging.

[0016] When the current state of the control pilot signal is state B2, the first control pilot state change detection circuit is used to detect a state change of the control pilot signal from state B2 to state B1, thereby waking the controller when the cable of the EVSE is connected to the vehicle-side charger and the EVSE is not ready for charging.

[0017] When the current state of the control pilot signal is state B2, the second control pilot state change detection circuit is used to detect a state change of the control pilot signal from state B2 to state A, thereby waking the controller when the cable of the EVSE is disconnected from the vehicle-side charger.

[0018] When the current state of the control pilot signal is state B1, the first control pilot state change detection circuit or the second control pilot state change detection circuit is used to detect a state change of the control pilot signal from state B1 to state A, thereby waking the controller when the cable of the EVSE is disconnected from the vehicle-side charger.

[0019] Furthermore, an electric vehicle with a drive battery and the OBC is planned. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows a functional block diagram of a power system of an electric vehicle, wherein the power system includes an on-board charger (OBC). Fig.2 is a block diagram of the OBC, wherein the OBC includes a control pilot (CP) wake-up circuit for receiving a control pilot (CP) signal from an EVSE and for waking an OBC controller of the OBC in response to a change in state of the CP signal. Fig. 3 is a schematic circuit diagram of the CP wake-up circuit, wherein the CP wake-up circuit includes a first CP state change detection circuit, a second CP state change detection circuit, and a contact monitoring integrated circuit (contact monitoring IC). Fig. 4 is a flowchart showing representative operations of the OBC controller for entering the sleep mode and the CP wake-up circuit for waking the OBC controller in response to a change in state of the CP signal. Fig.5 is a table indicating which CP state change detection circuit of the CP wake-up circuit is used for detecting a change in the state of the CP signal while the OBC controller is asleep and for generating a wake-up signal for waking up the OBC controller. Fig. 6 is a timing diagram showing a polling sequence performed by the contact monitoring IC of the CP wake-up circuit on the CP state change detection circuits of the CP wake-up circuit. Fig. 7 and Fig. 8 are respectively graphs corresponding to the charging process of a first capacitor (C2) and a second capacitor (C2s) of the second CP state change detecting circuit during the polling sequence operation performed by the contact monitoring IC. Fig.9 shows a measurement output while the OBC controller is asleep and then awakened in response to a change in the state of the CP signal, the measurement output including a curve of the voltage of the CP signal, a curve of the current injected by the contact monitoring IC to first and second capacitors of a selected one of the CP state change detection circuits, a curve of the voltage of the second capacitor of the selected CP state change detection circuit, and a curve of the voltage of a wake-up signal. DETAILED DESCRIPTION

[0020] Embodiments of the invention are described in detail below. However, it should be understood that the embodiments described herein are merely exemplary of the invention, which may be embodied in various other forms. The figures are not necessarily to scale, and some portions may be exaggerated to show details of particular components. The details of construction and function described herein are not to be interpreted in a limiting sense, but merely as a representative basis for one skilled in the art to practice the invention.

[0021] The functional block diagram of Fig.1 shows a power system 10 of an electric vehicle (EV) 12 according to one or more embodiments. The power system 10 includes an on-board charger (OBC) 18. The OBC 18 is located onboard the electric vehicle 12. An electric vehicle (EV) is defined herein as a vehicle that uses electricity to propel the vehicle and may be a battery-only vehicle (BEV), a hybrid vehicle (HEV), a plug-in hybrid vehicle (PHEV), etc. The OBC 18 is used to charge a high-voltage (HV) direct current (DC) traction battery 14 of the EV 12. The traction battery 14 must be charged to provide electricity for use by the electric motor 16 to propel the EV 12.

[0022] The OBC 18 charges the traction battery 14 using electrical power from a charging station 22. The OBC 18 is connected to the charging station 22 via a cable 20. The cable 20 has a connector at one end that can be received with a charging port of the EV 12. The OBC 18 is electrically connected to the charging port of the EV 12. In operation, the OBC 18 receives electrical power from the charging station 22 via the cable 20 and uses this electrical power to charge the traction battery 14. The cable 20, the charging station 22, and other installed elements that enable the OBC 18 to receive energy from an electrical utility grid to which the charging station 22 is connected are collectively referred to herein as electric vehicle supply equipment (EVSE) 24.

[0023] In an "AC-to-DC charging" variation, the OBC 18 charges the traction battery 14 using electrical power received from the power grid via the charging station 22. In operation, the OBC 18 receives electrical power from the charging station 22 via the cable 20, converts the electrical power to a direct current, and charges the traction battery 14 with the direct current.

[0024] Alternatively, in a "DC charging" variation, such as "fast DC charging" or "DC rapid charging," the OBC 18 charges the traction battery 14 using a direct current received from the charging station 22. In operation, the OBC 18 transfers power from the charging station 22 directly to the traction battery 14 to charge the traction battery with the direct current.

[0025] The OBC 18 may include electronic or other elements operable to control and manage power flow to support charging-related operations for the traction battery 14, and optionally to support charging or otherwise powering a low voltage (LV) battery 26, one or more vehicle subsystems 28, and / or other electronically operable elements within the EV 12. The LV battery 26 may be included to support powering vehicle subsystems 28 operating at lower voltages than the electric motor 16, such as remote keyless entry (RKE) systems, heating and cooling systems, infotainment systems, banking systems, etc.

[0026] In addition to charging with the power provided via cable 20, the traction battery 14, the LV battery 26, and the vehicle subsystems 28 may be operated to supply energy to one another and / or be supplied with energy generated by the electric motor 16. For example, the LV battery 26 may be operated to provide sufficient current for use by a low-voltage source 30. The low-voltage source 30 may be operated to regulate current from the LV battery 26 for use by the OBC 18 and one or more vehicle subsystems 28.

[0027] The terms "low," "low," and "high" are used herein by way of example to indicate voltage levels of approximately 5 VDC, 12 VDC, and 200 VDC, respectively, as commonly used in vehicles to enable operation in conjunction with corresponding power sources. However, the invention is not limited thereto, and various other power sources with the same or different voltage levels and / or power generation capabilities may also be used. For example, according to international regulations, safe voltages (below 50 VAC and 75 VDC) are referred to as "low," and in most European regions, a voltage level of approximately 400 VDC is referred to as "high."

[0028] The low voltage source 30 can be operated to set a voltage used by the OBC 18 for testing the connection of the cable 20, to generate a wake-up signal, etc. The low voltage source 30 can be, for example, a voltage or current regulator with sufficient capabilities to compensate for a voltage variation of the traction battery 14 and / or the LV battery 26 so that they provide a stable current to the OBC 18 and / or other electrically connected elements that may be sensitive to voltage variations. Although shown in the functional block diagram of Fig. 1 as a separate element, the low voltage source 30 may be included as an electrical element in the OBC 18.

[0029] The power system 10 further includes a vehicle controller 32. The vehicle controller 32 is an electronic device such as a processor, a microcontroller, or the like (e.g., a computer). The vehicle controller 32 enables the execution of logical operations and other processing requirements of the EV 12. The vehicle controller 32 is connected to the OBC 18 and is operable to communicate with and control other nodes of the EV 12, including nodes for charging applications. Optionally, one or more of the elements of the power system 10 may include its own controller or processor.

[0030] With reference to the block diagram of Fig. 2 and continue on Fig. 1, an OBC 18 according to one or more embodiments is shown below.

[0031] For AC-to-DC charging, the OBC 18 includes a charging unit, such as an OBC converter 34, operable to convert power received from the power grid via the EVSE 24 to a direct current required to charge the traction battery 14. Accordingly, the OBC converter 34 may include an AC-to-DC converter and other associated electronic devices operable to convert the power received from the power grid to a form usable for charging the traction battery 14. For example, the OBC converter 34 may include electronic devices for correcting the power factor to meet regulatory standards or providing DC-to-DC conversion in accordance with charging profiles of the traction battery 14.

[0032] For "DC charging," a charging unit such as an OBC relay 35 is provided. The OBC relay 35 may be part of the OBC 18 or may be provided as a separate component from the OBC 18. The OBC relay 35 can be controlled to an open position or a closed position. When the OBC relay 35 is closed, direct current can be received from the charging station 22 through the OBC 18 and transmitted directly to the traction battery 14 via the OBC relay. When the OBC relay 35 is open, no current can be transmitted to the traction battery 14 via the OBC relay.

[0033] The OBC 18 includes an OBC controller 36. The OBC controller 36 is an electronic device such as a processor, a microcontroller, or the like (e.g., a computer). The OBC controller 36 is operable to handle control algorithms for the OBC functions described above. The OBC controller 36 may detect the connection of the cable 20 to the charging port of the EV 12, identify the charging cable and / or connector, and control and monitor switching devices or other electronic devices associated with the OBC 18. The OBC controller 36 may communicate with the vehicle controller 32 to convey charging status and other information corresponding to the operation of the OBC 18.

[0034] The OBC controller 36 can operate in a sleep mode or a wake mode. The OBC controller 36 in the wake mode is configured to control the charging unit (i.e., the OBC converter 34 and / or the OBC relay 35) to charge the traction battery 14 with power from the EVSE 24. Otherwise, when the OBC controller 36 is in the sleep mode, the charging unit cannot charge the traction battery 14 with power from the EVSE 24.

[0035] For AC-to-DC charging, the OBC controller 36 controls the OBC converter 34 to convert the current from the charging station 22 to a direct current and to charge the traction battery 14 with the direct current. For example, the OBC controller 36 controls the switching and switching duration of the power transistor switches (not shown) of the OBC converter 34 to convert the current to the selected level of direct current.

[0036] For "DC charging," depending on the architecture of the electric vehicle, the OBC controller 36 either directly controls the OBC relay 35 to close or communicates with an OBC relay 35 controller to close the OBC relay 35 when direct current from the charging station 22 is to be transferred directly to the traction battery 14. The OBC relay 35 is open at all other times. Therefore, the OBC relay 35 must be controlled by the OBC controller 36 to close.

[0037] The OBC controller 36 is shown as an integrated controller, but it may also be provided separately from and electrically connected to the OBC 18. The OBC converter 34 and / or the OBC relay 35, the OBC controller 36, and the associated electronic control devices, which may or may not be integrated with the OBC 18, may form a vehicle-mounted charging system 37.

[0038] In addition to providing power from the utility grid, the EVSE 24 generates a control pilot (CTRLPLT) signal ("CP signal"). The CP signal can be read and acknowledged by the OBC 18. The CP signal has a defined signal format in accordance with industry standards and provides the OBC 18 with the necessary information for correct AC-to-DC charging modes. The CP signal conveys information to the OBC controller 36 for use in starting and monitoring the charging process of the traction battery 14.

[0039] The main functions of the CP signal include being used to check the continuity of the body's connection to the ground of the EVSE 24. If this signal is not present at the OBC input, charging is not permitted. The CP signal may contain a command from the EVSE 24 to the OBC 18 indicating the maximum current the OBC can receive from the power grid for charging the traction battery 14. This command may be included in the duty cycle of the CP signal and may be converted into available amperes from the power grid according to predefined criteria, such as specific formulas defined in the relevant regulatory standards. To this end, the CP signal is generated using pulse-width modulation (PWM). The CP signal may also provide a response from the EV 12 to the EVSE 24, informing the EVSE that the EV is ready to accept charging. After this, the charging process may begin.

[0040] For example, in accordance with relevant regulatory standards, the CP signal has the following main characteristics: Supply voltage range: Vg = ±12 V ±0.6 V (tolerance); Duty cycle (D): 0% ≤ D < 100%; and Frequency (fCP) when 0% < D < 100%: 1 kHz nominal ±3% (tolerance).

[0041] For these main features, the CP signal has the following state definitions: State B1: Vg = 12V, D = 100% → the cable 20 is connected to the EV 12 (i.e. plugged in), but the EVSE 24 is not ready to transfer power from the charging station 22 to the EV; State B2: Vg = ±12V, 5% ≤ D ≤ 95% ±0.5% (tolerance) → the cable 20 is connected to the EV 12 and the EVSE 24 is ready to transfer power from the charging station 22 to the EV; and State A or E / F - neither of these states allows power to be transferred from the charging station. For example, in state A, the CP signal is 0V → cable 20 is not connected to the EV 12.

[0042] The electric vehicle stage effects of the different CP states are as follows: State A: Cable 20 is not connected to the EV 12. For example, the EV 12 has been parked in the vehicle user's private parking space, but the EV does not need to be charged. The OBC 18 enters sleep mode in State A after preliminary conditions have been met. State B1: The cable 20 is connected to the EV 12, but the EVSE 24 is not ready for charging. For example, the vehicle user arrives at the charging station 22 with the EV 12 and plugs the cable 20 into the EV's charging port. However, the EVSE 24 is unable to supply power from the charging station 22 to the EV 12 due to an overload. The OBC 18 enters sleep mode under state B1 after preliminary conditions are met. State B2: The cable 20 is connected to the EV 12, and the EVSE 24 is ready for charging. For example, the charging cycle has ended, but the cable 20 is still plugged into the charging port of the EV 12. The OBC 18 enters sleep mode after preliminary conditions are met. The OBC 18 wakes up from sleep mode when the cable 20 is disconnected from the EV 12 because the CP signal is no longer present.

[0043] As in Fig.2, the OBC 18 further includes a control pilot (CP) wake-up circuit 38 for waking the OBC 18. In particular, the CP wake-up circuit 38 wakes the OBC controller 36 when the OBC controller is in the sleep mode (ie, in a low sleep current mode).

[0044] For AC-to-DC charging, while the OBC controller 36 is asleep, the OBC 18 cannot receive power from the charging station 22 and convert it to a DC current for charging the traction battery 14 because the OBC controller must be awake to control the operation of the OBC converter 34. Therefore, the OBC 18 is effectively asleep while the OBC controller 36 is asleep. Conversely, if the OBC controller 36 is awake, the OBC 18 can receive power from the charging station 22 and convert it to a DC current for charging the traction battery 14 because the OBC controller is awake to control the operation of the OBC converter 34. Thus, the OBC 18 is effectively awake while the OBC controller 36 is awake.

[0045] For "DC charging," while the OBC controller 36 is dormant, no direct current can be transferred from the charging station 22 to the traction battery 14 because the OBC controller must be awake to either directly control the operation of the OBC relay 35 or to communicate with a controller of the OBC relay 35 to indirectly control the operation of the OBC relay 35. Thus, the OBC 18 is effectively dormant while the OBC controller 36 is dormant. Conversely, when the OBC controller 36 is awake, direct current can be transferred from the charging station 22 to the traction battery 14 because the OBC controller is awake to directly or indirectly control the operation of the OBC relay 35. Thus, the OBC 18 is effectively awake while the OBC controller 36 is awake.

[0046] In operation, the CP wake-up circuit 38 receives the CP signal from the EVSE 24. In one or more embodiments, the CP wake-up circuit 38 processes the CP signal to detect a change in state of the CP signal. The CP wake-up circuit 38 generates a wake-up signal in response to detecting a change in state of the CP signal. The CP wake-up circuit 38 provides the generated wake-up signal to the OBC controller 36 to wake the OBC controller and cause the OBC controller to exit sleep mode.

[0047] The CP wake-up circuit 38 and its function should not only provide desired wake-up capabilities, but also meet other requirements related to the wake-up requirements. Specific wake-up requirements include waking the OBC controller 36 when the state of the CP signal changes, with the wake-up being performed relatively quickly, for example, less than 0.2 seconds. Related requirements include a relatively low quiescent current, for example, less than 200 µA.

[0048] With reference to the schematic diagram of Fig. 3 and continue on Fig. 1 and Fig. 2, the CP wake-up circuit 38 is described below. The CP wake-up circuit comprises a first CP state change detection circuit 42 (as “Block 1” in Fig. 3), a second CP state change detection circuit 44 (as “Block 2” in Fig.3) and a contact monitoring integrated circuit (contact monitoring IC) 46. The CP state change detection circuits 42 and 44 each receive the CP signal from the EVSE 24. As explained in more detail below, the contact monitoring IC 46 monitors how the first and / or second CP state change detection circuits 42 and 44 are operated by the CP signal to detect state changes of the CP signal.

[0049] The first and second CP state change detection circuits 42 and 44 each have a similar circuit layout and similar electronic components as in Fig. 3. The first and second CP state change detection circuits 42 and 44 differ in that the switch S1 of the first CP state change detection circuit is a PMOS device, while the corresponding switch S2 of the second CP state change detection circuit is an NMOS device.

[0050] With reference to flowchart 50 of Fig. 4 and continue on Fig. 1, Fig. 2 and Fig.3, representative operations of the OBC controller 36 for entering the sleep mode and the CP wake-up circuit 38 for waking the OBC controller in response to a change in state of the CP signal are explained below. The operations begin with the OBC controller 36 receiving a request for the OBC 18 to enter the sleep mode, as indicated in block 52. In response, the OBC controller 36 checks the current state of the CP signal, as shown in block 54. As described above, the current state of the CP signal may be state A or E / F, state B1, or state B2. The OBC controller 36 then configures a contact monitor provided by the contact monitor IC 46 in accordance with the current state of the CP signal, as indicated in block 56.

[0051] The OBC controller 36 then enters sleep mode. Specifically, if, in response to the sleep mode request in block 52, the current state of the CP signal is state A or E / F as indicated in block 58a, the OBC controller 36 enters sleep mode as indicated in block 60a. Similarly, if, in response to the sleep mode request, the current state of the CP signal is state B1 as indicated in block 58b, the OBC controller 36 enters sleep mode as indicated in block 60b. And, if, in response to the sleep mode request, the current state of the CP signal is state B2 as indicated in block 58c, the OBC controller 36 enters sleep mode as indicated in block 60c.

[0052] While the OBC controller 36 is idle, the contact monitoring IC 46 monitors a change in the state of the CP signal. The contact monitoring IC 46 monitors first and / or second CP state change detection circuits 42 and 44, which are operated by the CP signal, to detect a change in the state of the CP signal. At this time, if the state of the CP signal is state A or E / F, the contact monitoring IC 46 detects whether the state of the CP signal has changed to state B1 or state B2, as indicated in decision block 62a. If the state of the CP signal is state B1, the contact monitoring IC 46 detects whether the state of the CP signal has changed to state B2 or state A or E / F, as indicated in decision block 62b.And when the state of the CP signal is state B2, the contact monitoring IC 46 detects whether the state of the CP signal has changed to state B1 or state A or E / F as indicated in decision block 62c.

[0053] If the state of the CP signal has not changed in the three decision blocks 62a, 62b, and 62c, the contact monitoring IC 46 continues monitoring for a change in the state of the CP signal. The contact monitoring IC 46 waits a period of time before resuming monitoring. This process is repeated until a change in the state of the CP signal occurs. As long as the state of the CP signal remains unchanged, the OBC controller 36 remains in sleep mode.

[0054] Once the contact monitoring IC 46 detects a change in the state of the CP signal in one of decision blocks 62a, 62b, and 62c, the contact monitoring IC generates a wake-up signal as indicated in block 64. The contact monitoring IC 46 provides the wake-up signal to the OBC controller 36. In response to receiving the wake-up signal, the OBC controller 36 powers up as indicated in block 66. After fully powering up, the OBC controller 36 exits sleep mode and is awake. The OBC 18 is thus effectively awake. The OBC controller 36 can then perform functions such as controlling the OBC converter 34 and / or the OBC relay 35 in accordance with the new state of the CP signal.

[0055] With reference to Table 70 of Fig. 5 and continue on Fig. 3 and Fig.4, it is described below how the first CP state change detection circuit 42 (i.e., block 1) and / or the second CP state change detection circuit 44 (i.e., block 2) of the CP wake-up circuit 38 are used to detect a change in the state of the CP signal while the OBC controller 36 is idle and to generate a wake-up signal for waking the OBC controller.

[0056] If, as in Fig.70, if the state of the CP signal is state A or E / F while the OBC controller 36 is idle and transitions to state B1, the first or second CP state change detection circuit 42 or 44 is used to detect this state change and generate a wake-up signal for waking the OBC controller. If the state of the CP signal is state A or E / F while the OBC controller 36 is idle and transitions to state B2, the second CP state change detection circuit 44 is used to detect this state change and generate a wake-up signal for waking the OBC controller.

[0057] The CP signal has a state A while the cable 20 is not connected to the EV 12. The state of the CP signal transitions from state A to state B1 when the cable 20 is connected to the EV 12 and the EVSE 24 is not ready for charging. Thus, the connection of the cable 20 to the EV 12 and the non-readiness of the EVSE 24 are detected using the first or second detection circuits 42 or 44. The state of the CP signal transitions from state A to state B2 when the cable 20 is connected to the EV 12 and the EVSE 24 is ready for charging. Thus, the connection of the cable 20 to the EV 12 and the readiness of the EVSE 24 are detected using the second detection circuit 44. The contact monitoring IC 46 generates a wake-up signal to wake the OBC controller 36 upon one of these detections. Thus, the OBC controller 36 is awakened when the cable 20 is connected to the EV 12.

[0058] As further shown in Table 70, when the state of the CP signal is state B1 while the OBC controller 36 is idle and transitions to state A or E / F, one of the first or second CP state change detection circuits 42 or 44 is used to detect this state change and generate the wake-up signal for waking the OBC controller. When the state of the CP signal is state B1 while the OBC controller 36 is idle and transitions to state B2, the first CP state change detection circuit 42 is used to detect this state change and generate a wake-up signal for waking the OBC controller.

[0059] The CP signal is in state B1 while the cable 20 is connected to the EV 12 and the EVSE 24 is not ready for charging. The state of the CP signal changes from state B1 to state A when the cable 20 is disconnected from the EV 12 and the EVSE 24 is not ready for charging. Thus, the disconnection of the cable 20 from the EV 12 and the unreadiness of the EVSE 24 for charging are detected using the first or second detection circuits 42 or 44. The contact monitoring IC 46 generates a wake-up signal for waking the OBC controller 36 upon this detection. Thus, the OBC controller 36 is woken when the cable 20 is disconnected from the EV 12.

[0060] The state of the CP signal changes from state B1 to state B2 when the EVSE 24 becomes ready for charging while the cable 20 is connected to the EV 12. The readiness of the EVSE 24 for charging while the cable 20 is connected to the EV 12 is detected using the first detection circuit 42. The contact monitoring IC 46 generates a wake-up signal to wake the OBC controller 36 upon this detection. Thus, the OBC controller 36 is awakened when the EVSE 24 becomes ready for charging while the cable 20 is connected to the EV 12.

[0061] As further shown in Table 70, when the state of the CP signal is state B2 while the OBC controller 36 is idle and transitions to state A or E / F, the second CP state change detection circuit 44 is used to detect this state change and generate a wake-up signal for waking the OBC controller. When the state of the CP signal is state B2 while the OBC controller 36 is idle and transitions to state B1, the first CP state change detection circuit 42 is used to detect this state change and generate a wake-up signal for waking the OBC controller.

[0062] The CP signal is in state B2 while the cable 20 is connected to the EV 12 and the EVSE 24 is ready for charging. The state of the CP signal changes from state B2 to state A when the cable 20 is disconnected from the EV 12 and the EVSE 24 is ready for charging. Thus, the disconnection of the cable 20 from the EV 12 and the unreadiness of the EVSE 24 for charging are detected using the second detection circuit 44. The contact monitoring IC 46 generates a wake-up signal to wake the OBC controller 36 upon this detection. Thus, the OBC controller 36 is awakened when the cable 20 is disconnected from the EV 12.

[0063] The state of the CP signal changes from state B2 to state B1 if the EVSE 24 does not become ready for charging while the cable 20 is connected to the EV 12. The non-readiness of the EVSE 24 for charging while the cable 20 is connected to the EV 12 is detected using the first detection circuit 42. The contact monitoring IC 46 generates a wake-up signal to wake the OBC controller 36 upon this detection. In this way, the OBC controller 36 is awakened if the EVSE 24 does not become ready for charging while the cable 20 is connected to the EV 12.

[0064] With reference to the timing diagram 80 of Fig. 6 and continue on Fig. 3, a query sequence performed by the contact monitoring IC 46 on the CP state change detection circuits 42 and 44 is described. The CP state change detection circuits 42 and 44 have a similar circuit layout as in Fig.3. Therefore, only the operation of the polling sequence at the second CP state change detection circuit 44 (Block 2) will be described below.

[0065] For example, assume that the state of the CP signal changes from state B2 to state A or E / F. While the OBC controller 36 is in sleep mode, the capacitors C2 and C2s of the second CP state change detection circuit 44 are periodically charged via the INO terminal of the contact monitoring IC 46. The contact monitoring IC 46 charges the capacitors C2 and C2s of the second detection circuit 44 at a frequency rate of 1 / t POLL_TIME . The frequency rate (1 / t POLL_TIME ) is much lower than the frequency (fCP) of the CP signal. As indicated by the arrow 82 in the timing diagram 80 of Fig. 6, mainly the capacitor C2 of the second detection circuit 44 is injected with a relatively small current (I CHARGE) during a relatively short period of time (t POLL_ACT_TIME ) is loaded. An example of the configuration of the contact monitoring IC 46 is I CHARGE = 5 mA, T POLL-TIME = 64 ms (control pilot signal = 1 ms) and t POLL_ACT_TIME = 128 µs.

[0066] The voltage of capacitor C2 of the second detection circuit 44 increases relatively quickly while capacitor C2s of the second detection circuit 44 is increasingly charged, and no pulses are present until capacitor C2s has the same voltage as capacitor C2. While the CP signal remains in state B2, while the CP signal has a duty cycle (D) of 5% ≤ D ≤ 95%, and a supply voltage Vg = ± 12V, when a positive control pilot pulse is received, capacitor C2 is discharged via resistor R2 of the second detection circuit, and consequently, capacitor C2s is discharged via resistors R2 and R2s of the second detection circuit 44.

[0067] However, when the state of the CP signal changes from state B2 to state A or E / F, the voltage of capacitor C2s increases and eventually reaches a preprogrammed threshold voltage. A wake-up signal output (WUP output) of contact monitoring IC 46 is triggered when the voltage of capacitor C2s becomes greater than the threshold voltage. In response, contact monitoring IC 46 provides a wake-up signal to OBC controller 36 to wake the OBC controller.

[0068] With reference to Fig. 7 and Fig. 8 and continue on Fig. 3 and Fig. 6, the charging process of the capacitors C2 and C2s during the polling sequence operation performed by the contact monitoring IC 46 is described in more detail below.

[0069] The curve diagrams of Fig.7 shows the charging process of the capacitors C2 and C2s during the query sequence operation. In particular, Fig.7: a first graph 120a of the CP signal curve versus time and a corresponding graph 120b showing a longer time version of the first graph 120a; a second graph 122a of the timing / duration curve 123 of the injected current charge provided by the INO terminal of the contact monitoring IC 46 and a corresponding graph 122b showing a longer time version of the second graph 122a; a third graph 124a of the capacitor C2 charge level curve 125 versus time and a corresponding graph 124b showing a longer time version of the third graph 124a; a fourth graph 126a of the curve 127 of the charge level of the capacitor C2s with respect to time and a corresponding graph 126b showing a version of the fourth graph 126a over a longer period of time;and a fifth graph 128a of the timing / duration curve 129 for measuring the charge level of the capacitor C2s from the IN23 terminal of the contact monitoring IC 46 and a corresponding graph 128b showing a version of the fifth graph 128a over a longer period of time.;

[0070] Fig. Figure 8 shows further curve diagrams of the charging process of the capacitors C2 and C2s during the query sequence operation. In particular, Fig. 8: a first curve diagram 130 of the curve 131 of the charge level of the capacitor C2 with respect to time and of the curve 132 of the charge level of the capacitor C2s with respect to time; a second curve diagram 134 of the curve 135 of the periodically injected current (I CHARGE ) with respect to time; a third curve diagram 136 of the curve 137 of the current of the capacitor C2 with respect to time; and a fourth curve diagram 138 of the curve 139 of the current of the capacitor C2s with respect to time.

[0071] As shown in the curve diagrams of Fig. 7 and Fig. As shown in Figure 8, in successive IN0 pulses, the capacitor C2 is charged and then transfers a voltage to the capacitor C2s (up to the same voltage level) until the capacitor C2s (at the IN23 evaluation window) is higher (in this state change example) than the defined threshold.

[0072] As described, when the OBC controller 36 is in sleep mode, the capacitors C2 and C2s of the second CP state change detection circuit 44 are periodically charged via the INO terminal of the contact monitoring IC 46. The contact monitoring IC 46 fully charges the capacitor C2, while the capacitor C2s remains almost unaffected (the resistance R2s + the capacitance combination of the capacitor C2s causes the capacitor C2s to charge much more slowly). The contact monitoring IC 46 outputs a current (ICHARGE) that primarily passes through the capacitor C2 and increases the voltage of the capacitor C2. The resistance R2s between the capacitors C2 and C2s practically prevents the current (I CHARGE) goes directly to capacitor C2s. Once the current injection from contact monitoring IC 46 is complete, capacitor C2 supplies increasing current to capacitor C2s until both capacitors are equally charged (i.e., have the same voltage). This sequence is performed as long as transistor S2 remains open.

[0073] Capacitor C2s is used to obtain a stable indication of the state change. The first capacitor C2 may be more affected by noise, but charging capacitor C2 and reading the IN23 pin can also be done before the CP signal changes while capacitor C2 is fully charged (see the curve diagrams of Fig. 7 and Fig.8). In summary, capacitor C2 is responsible for "receiving" current from the contact monitoring circuit, and the other capacitor C2s is responsible for charging "slow enough" for discharge via a CP signal oscillation.

[0074] With reference to Fig. 9 and continue on Fig. 3 and Fig.6, a measurement output 90 is explained below. The measurement output 90 is taken while the OBC controller 36 is asleep and then awakened in response to a change in the state of the CP signal. The measurement output 90 includes a curve 92 of the voltage of the CP signal, a curve 94 of the current injected by the contact monitoring IC 46 to the capacitors C2 and C2s of the second detection circuit 44, a curve 96 of the voltage of the capacitor C2s of the second detection circuit, and a curve 98 of the voltage of the wake-up signal. A first timing event flag ("1") 100, a second timing event flag ("2") 102, a third timing event flag ("3") 104, and a fourth timing event flag ("4") 106 are superimposed on the measurement output 90.

[0075] The measurement output 90 indicates chronological events that cause the CP wake-up circuit 38 to wake up the OBC controller 36. From the entry of the OBC controller 36 into sleep mode until the OBC controller wakes up in response to the wake-up request from the CP wake-up circuit 38, the Fig. 6 is periodically performed. As described, the interrogation sequence includes injecting a current pulse to capacitors C2 and C2s of second detection circuit 44 by contact monitoring IC 46 and then evaluating the voltage of capacitor C2s.

[0076] In the example of measurement output 90, the preconditions include maintaining the OBC controller 36 in sleep mode while the cable 20 connects the OBC 18 to the EVSE 24 and the CP signal is in state B2. Until the second timing event flag 102, the CP signal transitions as defined by state B2 with Vg = ±12 V and (5% ≤ D ≤ 95%) as shown in curve 92.

[0077] The contact monitoring IC 46 injects a current (I CHARGE ) from its terminal IN0 to the capacitors C2 and C2s of the second detection circuit 44 during T POLL_ACT_TIME (128 µs) each T POLL-TIME(64 ms). The first, third, and fourth timing event flags 100, 104, and 106 each indicate that the contact monitoring IC 46 initiates a current injection to the capacitors C2 and C2s. The current injected by the contact monitoring IC 46 to the capacitors C2 and C2s is represented by curve 94. The injected current charges the capacitors C2 and C2s. The voltage of the capacitor C2s is represented by curve 96. The voltage of the terminal IN23 of the contact monitoring IC 46 is evaluated within a short time after the end of the current injection. The voltage of the terminal IN23 of the contact monitoring IC 46 is the voltage of the capacitor C2s.

[0078] During the first timing event 100, the state of the CP signal remains in state B2. Consequently, due to the presence of PWM in the CP signal (i.e., due to the CP signal alternating with Vg = ±12 V and 5% ≤ D ≤ 95%), the voltage of capacitor C2s does not reach a preprogrammed wake-up voltage threshold while IN 23 is being evaluated. The wake-up voltage threshold is indicated by "WK_TH2" at measurement output 90. For example, in this scenario, the wake-up voltage threshold is 3.8 V.

[0079] At the second timing event 102, the state of the CP signal changes from state B2 to state A. The CP signal is equal to 0V as defined by state A, as shown in the curve 92 of the CP signal following the second timing event flag 102.

[0080] The second timing event 102 occurs during t POLL_TIME(64 ms) following that the contact monitoring IC 46 initiates a current injection at the first timing event 100. After expiration of T POLL-TIME(64 ms) following the first timing event 100 (i.e., after completion of a polling sequence), the contact monitoring IC 46 initiates another round of current injection to the capacitors C2 and C2s at the third timing event 104 (i.e., a new polling sequence is initiated). The voltage of the terminal IN23 of the contact monitoring IC 46 is evaluated within a short time after the end of the current injection during the third timing event 104. In this case, due to the change in the state of the CP signal, the capacitors C2 and C2s are not discharged, so their voltages increase. At this time, the current supplied to the capacitors C2s is not sufficient to cross the wake-up voltage threshold. The capacitor C2s is slowly charged, and its voltage already becomes greater than the voltage threshold WK_TH2 at the fourth timing event 106.

[0081] At timing event 106, contact monitoring IC 46 initiates another round of current injection to capacitors C2 and C2s (i.e., another polling sequence is initiated). The voltage of capacitor C2s has already become greater than the wake-up voltage threshold. The voltage of terminal IN23 of contact monitoring IC 46, which is the voltage of capacitor C2s, is evaluated within a short time after the end of the current injection during the fourth timing event 106. In response to contact monitoring IC 46 detecting that the voltage of capacitor C2s becomes greater than the wake-up voltage threshold, the contact monitoring IC generates a wake-up signal and provides it to OBC controller 36 to wake the OBC controller.

[0082] The function of the second state change detection circuit 44 (Block 2) has been described above. Conceptually, the first state change detection circuit 42 (Block 1) functions in the same way as the second detection circuit 44. The second detection circuit 44 is configured to detect state changes of the CP signal from (i) state B1 or state B2 to (ii) state A, while the first detection circuit 42 is configured to detect state changes of the CP signal from (i) state A or state B2 to (ii) state B1.

[0083] The following tables provide further operating details of the first state change detection circuit 42 (Block 1) and the second state change detection circuit 44.

[0084] The effect of each CP state on the Block 1 and Block 2 circuits is given in the following table: Block1 Block 2 CP S1 (PMOS) C1 & C1 S2 (NMOS) C2 & C2s Condition A Duty cycle 0% (0V) conductive (switch ElN) practically discharged non-conductive (switch OFF) fully charged Condition B1 Duty cycle 100% (~12V) non-conductive (switch OFF) fully charged conductive (switch ON) practically discharged Condition B2 Duty cycle [5.95]% (oscillating) periodic switching practically discharged periodic switching practically discharged

[0085] The change in the voltage of the capacitor C2s at each CP state change (and how the threshold is “exceeded”) is given in the following table: Which block should be used? CP state changes to (generating wake-up) A or E / F B1 B2 CP state when entering sleep mode A or E / F Block 1 (Vc 1s > Threshold1) Block 2 (V c2s < threshold2) Block 2 (V c2s < threshold2) B1 Block 1 (Vc 1s < Threshold1) Block 2 (V c2s > Threshold2) Block 1 (Vc 1s < threshold1) B2 Block 2 (V c2s > Threshold2) Block 1 (Vc 1s > Threshold1)

[0086] The contact monitoring IC 46 can be programmed to I CHARGE , T POLL-TIME and t POLL_ACT_TIME and set multiple voltage thresholds corresponding to wake-up needs depending on the state of the CP signal. The OBC controller 36 can perform such programming of the contact monitoring IC 46 and can do so before the OBC controller enters the sleep state. In this way, the use of the contact monitoring IC 46 enables OEM requirements regarding wake-up capabilities, wake-up time, and sleep current to be met.

[0087] Requirements for wake-up time and quiescent current are becoming increasingly stringent. The development of EV charging stations requires the addition of new wake-up reasons in electrification products. Therefore, leading wake-up requirements include wake-up at every change of state of the CP signal, a wake-up time of less than 200 ms, and a quiescent current of less than 200 µA. As described herein, the CP wake-up circuit 38 provides a simple and cost-effective solution to the most important wake-up requirements using a state-change detector current-sourced circuit. In particular, the CP wake-up circuit 38 includes first and second CP state-change detection circuits 42 and 44, which consist of a minimal number of electronic components, and a contact monitoring IC 46, which is common to both detection circuits, to provide the expected wake-up and keep power consumption low.

[0088] While exemplary embodiments have been described above, the invention is not limited to the embodiments described herein. This description is intended to be exemplary and not restrictive, and various changes may be made to the embodiments described herein without departing from the scope of the invention. Furthermore, features of different embodiments may be combined to form further embodiments of the invention.

Claims

[1] Vehicle-side charger (18) for an electric vehicle (12), comprising: a charging unit operable to receive power from an electric vehicle supply equipment (24), Electric Vehicle Supply Equipment or EVSE (24), for charging a traction battery (14) of the electric vehicle (12), a control device (36) operable in a sleep mode or a wake mode, wherein the control device (36) is configured in the wake mode to control the charging unit for charging the traction battery (14) with the energy from the EVSE (24), and a control pilot wake-up circuit (38) comprising a contact monitoring circuit (46), a first control pilot state change detection circuit (42), and a second control pilot state change detection circuit (44), such that the contact monitoring circuit (46) is common to the first control pilot state change detection circuit (42) and the second control pilot state change detection circuits (44), wherein the control pilot wake-up circuit (38) is configured to receive a control pilot signal from the EVSE (24), to detect a change in the current state of the control pilot signal while the controller (36) is in the sleep mode, and to generate a wake-up signal for waking the controller (36) in response to the current state of the control pilot signal changing to a first new state or a second new state, and wherein the first control pilot state change detection circuit (42) is configured todetect a change in the current state of the control pilot signal to the first new state, and the second control pilot state change detection circuit (44) is configured to detect a change in the current state of the control pilot signal to the second new state. [2] A vehicle-mounted charger according to claim 1, wherein: the charging unit comprises (i) a converter (34) operable to convert the energy received from the EVSE (24) into a usable form for charging the traction battery (14), and (ii) a relay (35) operable to transfer the energy received from the EVSE directly to the traction battery (14). [3] The vehicle-mounted charger according to claim 1, wherein the first and second control pilot state change detection circuits (42, 44) comprise similar electronic components. [4] A vehicle-mounted charger according to claim 3, wherein: the electronic components of the first control pilot state change detection circuit (42) comprise a first capacitor, the contact monitoring circuit (46) is operable to periodically inject a current pulse to the first capacitor for charging the first capacitor, wherein the electronic components of the first control pilot state change detection circuit (42) are arranged such that the first capacitor is discharged after receiving the current pulse while the current state of the control pilot signal remains unchanged, and is charged to a voltage greater than a threshold value when one or more current pulses are received after the current state of the control pilot signal has changed from the current state to the first new state, and the contact monitoring circuit (46) is further operable to generate the wake-up signal for waking the control device (36) in response to the voltage of the first capacitor becoming greater than the threshold value due to the change of the current state of the control pilot signal to the first new state. [5] A vehicle-mounted charger according to claim 4, wherein: the electronic components of the second control pilot state change detection circuit (44) comprise a second capacitor, the contact monitoring circuit (46) is operable to periodically inject a current pulse to the second capacitor for charging the second capacitor, wherein the electronic components of the second control pilot state change detection circuit (44) are arranged such that the second capacitor is discharged after receiving the current pulse while the current state of the control pilot signal remains unchanged, and is charged to a voltage greater than the threshold value when one or more of the current pulses are received after the current state of the control pilot signal has changed from the current state to the second new state, and the contact monitoring circuit (46) is further operable to generate the wake-up signal for waking the control device (36) in response to the voltage of the second capacitor becoming greater than the threshold value due to the change of the current state of the control pilot signal to the second new state. [6] A vehicle-mounted charger according to claim 2, wherein: the first control pilot change state detection circuit (42) and the second control pilot change state detection circuit (44) are both usable for detecting a change of the current state of the control pilot signal to a third new state. [7] The vehicle-mounted charger according to claim 1, wherein the states of the control pilot signal include a state (A) in which the voltage of the control pilot signal is zero volts, a state (B1) in which the voltage of the control pilot signal is a constant, positive value other than zero volts, and a state (B2) in which the voltage of the control pilot signal is an alternating value other than zero volts, wherein: the control pilot wake-up circuit (38) includes a first control pilot state change detection circuit (42) and a second control pilot state change detection circuit (44), wherein the first and second control pilot state change detection circuits (42, 44) each have similar electronic components, wherein, when the current state of the control pilot signal is the state (B1) or the state (B2), the first control pilot change state detection circuit (42) is used to detect a change in state of the control pilot signal from the state (B1) to the state (B2) or from the state (B2) to the state (B1), and wherein, when the current state of the control pilot signal is the state (A) or the state (B2), the second control pilot change state detection circuit (44) is used to detect a change in state of the control pilot signal from the state (A) to the state (B2) or from the state (B2) to the state (A). [8] A vehicle-mounted charger according to claim 7, wherein: when the current state of the control pilot signal is the state (A) or the state (B1), the first control pilot change state detection circuit (42) or the second control pilot change state detection circuit (44) is used to detect a change in state of the control pilot signal from the state (A) to the state (B1) or from the state (B1) to the state (A). [9] The vehicle-side charger of claim 1, wherein the states of the control pilot signal include a state (A) indicating that a cable (20) of the EVSE (24) is disconnected from the vehicle-side charger (18), a state (B1) indicating that the cable (20) of the EVSE (24) is connected to the vehicle-side charger (18) but the EVSE (24) is not ready for charging, and a state (B2) indicating that the cable (20) of the EVSE (24) is connected to the vehicle-side charger (18) and the EVSE (24) is ready for charging. wherein the control pilot wake-up circuit (38) includes a first control pilot change state detection circuit (42) and a second control pilot change state detection circuit (44), wherein the first and second control pilot change state detection circuits (42, 44) comprise similar electronic components, and wherein, when the current state of the control pilot signal is state (A), the second control pilot change state detection circuit (44) is used to detect a change in state of the control pilot signal from state (A) to state (B2), thereby waking the controller (36) when the cable (20) of the EVSE (24) is connected to the on-board charger (18) and the EVSE (24) is ready for charging. [10] The vehicle-side charger of claim 9, wherein, when the current state of the control pilot signal is state (A), the first control pilot change state detection circuit (42) or the second control pilot change state detection circuit (44) is used to detect a change in state of the control pilot signal from state (A) to state (B1), thereby waking the controller (36) when the cable (20) of the EVSE (24) is connected to the vehicle-side charger (18) and the EVSE (24) is not ready for charging. [11] The vehicle-side charger of claim 9, wherein, when the current state of the control pilot signal is state (B1), the first control pilot change state detection circuit (42) is used to detect a change in state of the control pilot signal from state (B1) to state (B2), thereby waking the controller (36) when the cable (20) of the EVSE (24) is connected to the vehicle-side charger (18) and the EVSE (24) is ready for charging. [12] The vehicle-side charger of claim 9, wherein, when the current state of the control pilot signal is state (B2), the first control pilot change state detection circuit (42) is used to detect a change in state of the control pilot signal from state (B2) to state (B1), thereby waking the controller (36) when the cable (20) of the EVSE (24) is connected to the vehicle-side charger (18) and the EVSE (24) is not ready for charging. [13] The vehicle-side charger of claim 9, wherein, when the current state of the control pilot signal is state (B2), the second control pilot change state detection circuit (44) is used to detect a change in state of the control pilot signal from state (B2) to state (A), thereby waking the controller (36) when the cable (20) of the EVSE (24) is disconnected from the vehicle-side charger (18). [14] The vehicle-side charger of claim 9, wherein, when the current state of the control pilot signal is state (B1), the first control pilot change state detection circuit (42) or the second control pilot change state detection circuit (44) is used to detect a change in state of the control pilot signal from state (B1) to state (A), thereby waking the controller (36) when the cable (20) of the EVSE (24) is disconnected from the vehicle-side charger (18). [15] Electric vehicle (12), comprising: a drive battery (14), and a vehicle-mounted charger (18) containing: a charging unit operable to receive energy from an electric vehicle supply equipment (24), Electric Vehicle Supply Equipment or EVSE (24), for charging the traction battery (14), a control device (36) operable in a sleep mode or a wake mode, wherein the control device (36) is configured in the wake mode to control the charging unit for charging the traction battery (14) with energy from the EVSE (24), and a control pilot wake-up circuit (38) comprising a contact monitoring circuit (46), a first control pilot state change detection circuit (42), and a second control pilot state change detection circuit (44), such that the contact monitoring circuit (46) is common to the first control pilot state change detection circuit (42) and the second control pilot state change detection circuits (44), wherein the control pilot wake-up circuit (38) is configured to receive a control pilot signal from the EVSE (24), to detect a change in the current state of the control pilot signal while the controller (36) is in the sleep mode, and to generate a wake-up signal for waking the controller (36) in response to the current state of the control pilot signal changing to a first new state or a second new state, and wherein the first control pilot state change detection circuit (42) is configured todetect a change in the current state of the control pilot signal to the first new state, and the second control pilot state change detection circuit (44) is configured to detect a change in the current state of the control pilot signal to the second new state. [16] The electric vehicle of claim 15, wherein the charging unit comprises (i) a converter (34) operable to convert the energy received from the EVSE (24) to a usable form for charging the traction battery (14), and (ii) a relay (35) operable to transfer the energy received from the EVSE (24) directly to the traction battery (14). [17] An electric vehicle according to claim 15, wherein the first and second control pilot change state detection circuits (42, 44) comprise similar electronic components. [18] Electric vehicle according to claim 17, wherein: the electronic components of the first control pilot change state detection circuit (42) comprise a first capacitor, wherein the contact monitoring circuit (46) is operable to periodically inject a current pulse to the first capacitor for charging the first capacitor, wherein the electronic components of the first control pilot change state detection circuit (42) are arranged such that the first capacitor is discharged after receiving the current pulse while the current state of the control pilot signal remains unchanged, and is charged to a voltage greater than a threshold value when one or more current pulses are received after the current state of the control pilot signal has changed from the current state to the first new state, and the contact monitoring circuit (46) is further operable to generate the wake-up signal for waking the control device (36) in response to the voltage of the first capacitor becoming greater than the threshold value due to the change of the current state of the control pilot signal to the first new state. [19] Electric vehicle according to claim 18, wherein: the electronic components of the second control pilot state change detection circuit (44) comprise a second capacitor, the contact monitoring circuit (46) is operable to periodically inject a current pulse to the second capacitor for charging the second capacitor, wherein the electronic components of the second control pilot state change detection circuit (44) are arranged such that the second capacitor is discharged after receiving the current pulse while the current state of the control pilot signal remains unchanged, and is charged to a voltage greater than the threshold value when one or more of the current pulses are received after the current state of the control pilot signal has changed from the current state to the second new state, and the contact monitoring circuit (46) is further operable to generate the wake-up signal for waking the control device (36) in response to the voltage of the second capacitor becoming greater than the threshold value due to the change of the current state of the control pilot signal to the second new state. [20] Electric vehicle according to claim 16, wherein: the first control pilot change state detection circuit (42) and the second control pilot change state detection circuit (44) can both be used to detect a change of the current state of the control pilot signal to a third new state.

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