Resolver Excitation Signal Ramp-Up for Transient Overcurrent Control

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Solution Overview

Problem

In hybrid electric vehicles and electric vehicles, the excitation signal generation for resolvers often results in overcurrents exceeding the actual application range due to transient responses, which can lead to inefficiencies and increased costs due to the need for larger drivers to manage these currents.

Innovation Solution

An apparatus and method that includes a sine wave generator, amplifier, differential signal generator, and processor to gradually increase the voltage of the excitation signal from a start voltage to a target voltage based on transient currents, limiting the current flow and preventing overcurrents by adjusting amplification ratios and voltage ranges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the excitation signal voltage is increased to the target voltage immediately, then the excitation signal strength is improved, but an overcurrent greater than the actual application range flows into the coil during transient response

Engineering Contradiction:

Improveexcitation signal strengthVSAvoidovercurrent

Core Design Contradiction:

PowerVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary action by calculating the transient current that would flow if the target voltage were applied immediately, and uses this calculation to determine an appropriate start voltage that prevents overcurrent while still achieving the desired excitation signal strength eventually

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system makes the excitation signal voltage dynamic by adjusting it based on the calculated transient current. The voltage is set to target voltage only when safe, otherwise it is set to a lower start voltage, creating a dynamic adaptation to prevent overcurrent while maintaining power effectiveness

Inventive Principle:

Principle #15Dynamics

2Reliability

If a larger driver is used to manage transient overcurrents, then the reliability of current management is improved, but the device complexity and cost increase

Engineering Contradiction:

Improvecurrent management reliabilityVSAvoiddriver size

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The system uses feedback by calculating the transient current based on coil parameters and using this calculated information to determine the appropriate excitation voltage level, enabling reliable current management through intelligent control rather than hardware oversizing

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system changes the operating parameters by adjusting the excitation voltage level dynamically based on calculated transient current characteristics, allowing reliable current management through parameter optimization rather than increasing driver capacity

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS12189367B2Apparatus and method for generating excitation signal for resolver

Publication Date: 2025.01.07 HYUNDAI MOBIS CO LTD

AI summary

Disclosed is an apparatus for excitation signal generation for a resolver. The apparatus includes a sine wave generator that generates a sine wave based on a square wave, an amplifier that amplifies the sine wave, a differential signal generator that converts, into a differential signal, the amplified sine wave, a driver that inputs the differential signal to a coil, and a processor that generates an excitation signal by increasing a voltage of the sine wave from a start voltage to a target voltage through at least one of the sine wave generator and the amplifier based on a transient current that flows into the coil in a transient response interval.