TECHNICAL FIELD

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

BACKGROUND

An on-board charger (OBC) of an electric vehicle is used for charging a traction battery of the vehicle. In one variation, the OBC converts electrical power received from an electric vehicle supply equipment (EVSE) connected to the grid into DC electrical power and charges the battery with the DC electrical power. In another variation, the OBC enables the battery to be charged directly with DC electrical power received from an EVSE.

SUMMARY

An on-board charger (OBC) for an electric vehicle includes a charge unit, a controller, and a control-pilot wake-up circuit. The charge unit is operable to receive energy from an electric vehicle supply equipment (EVSE) for charging a traction battery of the electric vehicle. The controller is operable to be in a sleep mode or in an awake mode. The controller in the awake mode is configured to control the charge unit to charge the traction battery with energy from the EVSE. The control pilot wake-up circuit is configured to receive a control pilot signal from the EVSE, detect for 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 up the controller in response to the current state of the control pilot signal changing to a new state. The charge unit may include at least one of (i) a power plant operable for converting energy received from the EVSE into a usable form for charging the traction battery and (ii) a relay operable for transferring energy received from the EVSE directly to the traction battery.

In one or more embodiments, the control pilot wake-up circuit includes a first control pilot state change detector circuit usable for detecting for a change in the current state of the control pilot signal to a first new state and a second control pilot state change detector circuit usable for detecting for a change in the current state of the control pilot signal to a second new state. The first and second control pilot state change detector circuits have a same kind of electronic components. The control pilot wake-up circuit further includes a contact monitoring circuit common to the first and second control pilot state change detector circuits.

The electronic components of the first control pilot state change detector 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 detector circuit are arranged such that the first capacitor discharges after receiving the current pulse while the current state of the control pilot signal remains unchanged and charges to have 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 up the controller in response to the voltage of the first capacitor becoming greater than the threshold due to the current state of the control pilot signal changing to the first new state.

The electronic components of the second control pilot state change detector 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 detector circuit are arranged such that the second capacitor discharges after receiving the current pulse while the current state of the control pilot signal remains unchanged and charges to have a voltage greater than the 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 second new state. The contact monitoring circuit is further operable to generate the wake-up signal for waking up the controller in response to the voltage of the second capacitor becoming greater than the threshold due to the current state of the control pilot signal changing to the second new state.

The first and second control pilot state change detector circuits are both usable for detecting for a change in the current state of the control pilot signal to a third new state.

In one or more embodiments, 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, non-zero value of volts, and a state B2 in which the voltage of the control pilot signal is an alternating, non-zero value of volts. When the current state of the control pilot signal is either the state B1 or the state B2, the first control pilot state change detector circuit is used for detecting for a change in state of the control pilot signal from either the state B1 to the state B2 or the state B2 to the state B1. When the current state of the control pilot signal is either the state A or the state B2, the second control pilot state change detector circuit is used for detecting for a change in state of the control pilot signal from either the state A to the state B2 or the state B2 to the state A. When the current state of the control pilot signal is either the state A or the state B1, either of the first control pilot state change detector circuit or the second control pilot state change detector circuit is used for detecting for a change in state of the control pilot signal from either the state A to the state B1 or the state B1 to the state A.

In one or more embodiments, states of the control pilot signal include a state A indicative of a cordset of the EVSE being disconnected from the on-board charger, a state B1 indicative of the cordset of the EVSE being connected to the on-board charger but the EVSE not being ready to charge, and a state B2 indicative of the cordset of the EVSE being connected to the on-board charger and the EVSE being ready to charge. When the current state of the control pilot signal is the state A, the second control pilot state change detector circuit is used for detecting for a change in state of the control pilot signal from the state A to the state B2 whereby the controller is woken up upon the cordset of the EVSE being connected to the on-board charger with the EVSE being ready to charge.

When the current state of the control pilot signal is the state A, either of the first control pilot state change detector circuit or the second control pilot state change detector circuit is used for detecting for a change in state of the control pilot signal from the state A to the state B1 whereby the controller is woken up upon the cordset of the EVSE being connected to the on-board charger with the EVSE not being ready to charge.

When the current state of the control pilot signal is the state B1, the first control pilot state change detector circuit is used for detecting for a change in state of the control pilot signal from the state B1 to the state B2 whereby the controller is woken up while the cordset of the EVSE is connected to the on-board charger upon the EVSE being ready to charge.

When the current state of the control pilot signal is the state B2, the first control pilot state change detector circuit is used for detecting for a change in state of the control pilot signal from the state B2 to the state B1 whereby the controller is woken up while the cordset of the EVSE is connected to the on-board charger upon the EVSE not being ready to charge.

When the current state of the control pilot signal is the state B2, the second control pilot state change detector circuit is used for detecting for a change in state of the control pilot signal from the state B2 to the state A whereby the controller is woken up upon the cordset of the EVSE being disconnected from the on-board charger.

When the current state of the control pilot signal is the state B1, either of the first control pilot state change detector circuit or the second control pilot state change detector circuit is used for detecting for a change in state of the control pilot signal from the state B1 to the state A whereby the controller is woken up upon the cordset of the EVSE being disconnected from the on-board charger.

An electric vehicle having a traction battery and the OBC is also provided.

