Control Pilot Wake-Up Circuit for EV On-Board Charger

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Solution Overview

Problem

Existing on-board charger (OBC) systems for electric vehicles lack an efficient mechanism to wake up the controller from sleep mode in response to changes in the control pilot signal, leading to delayed charging initiation and increased power consumption.

Innovation Solution

A control pilot wake-up circuit that includes first and second control pilot state change detector circuits and a contact monitoring circuit, which detect changes in the control pilot signal by charging capacitors and generating a wake-up signal when the signal state changes, allowing the OBC controller to quickly transition from sleep mode to awake mode.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the OBC controller remains in sleep mode to reduce power consumption, then energy efficiency is improved, but the response time to charging requests deteriorates

Engineering Contradiction:

Improvepower consumptionVSAvoidwake-up time

Core Design Contradiction:

Use of energy by moving objectVSLoss of time

Solution Approach 1:

The control pilot wake-up circuit continuously monitors the control pilot signal even when the OBC controller is in sleep mode. This preliminary monitoring action allows the system to detect charging requests immediately without needing to fully wake the controller, thus maintaining low power consumption while ensuring rapid response to charging needs.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The control pilot wake-up circuit acts as an intermediary between the EVSE and the OBC controller. It receives and monitors control pilot signals from the EVSE, detects state changes, and only wakes up the controller when necessary. This intermediary mechanism enables the controller to remain in low-power sleep mode most of the time while still being able to respond quickly to charging requests.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Speed

If the OBC controller continuously monitors the control pilot signal to ensure rapid response, then response time is improved, but power consumption increases

Engineering Contradiction:

Improveresponse speedVSAvoidpower consumption

Core Design Contradiction:

SpeedVSUse of energy by moving object

Solution Approach 1:

The monitoring function is segmented into two parts: continuous monitoring by the low-power wake-up circuit and intermittent full monitoring by the main controller. The wake-up circuit handles continuous signal detection with minimal power consumption, while the controller only activates for full processing when a state change is detected, thus achieving both rapid response and energy efficiency.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The wake-up circuit uses periodic sampling of the control pilot signal instead of continuous full monitoring. By periodically checking for state changes and only waking the controller when necessary, the system maintains responsive behavior while significantly reducing the average power consumption compared to continuous monitoring.

Inventive Principle:

Principle #19Periodic action

3Productivity

If the OBC controller wakes up immediately for every control pilot signal change, then charging initiation speed is improved, but unnecessary wake-ups increase power consumption

Engineering Contradiction:

Improvecharging initiation speedVSAvoidpower consumption

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The wake-up circuit incorporates feedback mechanisms to verify signal state changes before triggering a controller wake-up. By monitoring the control pilot signal states and comparing them against expected valid transitions, the system can distinguish between genuine charging requests and transient noise, ensuring rapid response to legitimate requests while avoiding unnecessary wake-ups that would waste energy.

Inventive Principle:

Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables rapid and efficient charging by ensuring the OBC controller wakes up promptly in response to changes in the control pilot signal, reducing power consumption and meeting stringent wake-up time requirements.

Implementation Method 1

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.

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS11368035B2Control pilot wake-up circuit for on-board charger

Publication Date: 2022.06.21 LEAR CORP

AI summary

An on-board charger (OBC) for an electric vehicle includes a charge unit, a controller, and a control pilot (CP) wake-up circuit. The charge unit is operable for receiving energy from an EVSE for charging a traction battery of the vehicle. The controller while awake can control the charge unit to charge the battery with energy from the EVSE. The CP wake-up circuit receives a control pilot (CP) signal from the EVSE, detects for a change in a current state of the CP signal while the controller is asleep, and generates a wake-up signal for waking up the controller in response to the current state of the CP signal changing to a new state. The CP wake-up circuit includes first/second detector circuits usable for detecting for a change in the current state of the CP signal to a first/second new state.