DC-DC Converter Control for Vehicle Battery Efficiency

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Solution Overview

Problem

Existing motorized vehicle systems face inefficiencies in power consumption due to the lack of effective control over the DC-to-DC converter, which affects the overall system efficiency when charging and discharging high-voltage batteries and supplying power to electrical loads.

Innovation Solution

An apparatus that includes a converter operating point setter and controller to optimize the voltage converter's operating points based on the charging/discharging amount of the main rechargeable battery, ensuring efficient power conversion and reducing power consumption by intermittently operating the motor and adjusting the converter's operation to match the system's highest efficiency regions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the DC-to-DC converter operates continuously to supply power to electrical loads, then the power supply reliability is improved, but the power consumption increases and efficiency decreases

Engineering Contradiction:

Improvepower supply reliabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The converter controller intermittently operates the DC-to-DC converter based on the operating points set by the converter operating point setter. The converter is activated when the current operating point deviates from the target operating point and deactivated when the target operating point is reached, creating a periodic on-off action that reduces power consumption while maintaining power supply reliability

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The converter operating point setter continuously monitors the charging/discharging amount of the main rechargeable battery and adjusts the target operating point accordingly. The converter controller compares the current operating point with the target operating point and adjusts the converter operation to minimize deviation, implementing a feedback control mechanism that optimizes efficiency while ensuring reliable power supply

Inventive Principle:

Principle #23Feedback

2Power

If the DC-to-DC converter operates at high power levels, then the power output to electrical loads is improved, but the conversion efficiency decreases

Engineering Contradiction:

Improvepower outputVSAvoidconversion efficiency

Core Design Contradiction:

PowerVSLoss of energy

Solution Approach 1:

The converter operating point setter dynamically adjusts the target operating point based on the charging/discharging amount of the main rechargeable battery. As the charging/discharging amount changes, the target operating point is updated to maintain optimal conversion efficiency across different power levels, allowing the converter to adapt its operation to match the most efficient operating conditions for the current power demand

Inventive Principle:

Principle #15Dynamics

3Loss of energy

If the converter operates to minimize battery losses, then the overall system efficiency is improved, but the complexity of control increases

Engineering Contradiction:

Improvebattery lossesVSAvoidcontrol complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The converter operating point setter changes the operating parameters (target operating point) based on the charging/discharging amount of the main rechargeable battery. By adjusting the target operating point according to the battery's state, the system minimizes battery losses and improves overall efficiency without requiring complex control algorithms, as the parameter adjustment follows a straightforward relationship with the battery's charging/discharging amount

Inventive Principle:

Principle #35Parameter changes

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

This solution enhances the electricity economy of the vehicle by reducing power consumption and improving overall system efficiency, while ensuring the motor operates at optimal points to meet driver requests and minimize battery losses.

Implementation Method 1

set operating points of the voltage converter, each specifying a power conversion efficiency representing a ratio of input power to the electrical loads to output power of the main rechargeable battery and an output current of the voltage converter

Methodology Applied

Scientific EffectPower conversion efficiency:

Data Source

PatentUS11065966B2Apparatus for controlling motorized vehicle

Publication Date: 2021.07.20 DENSO CORP

AI summary

In an apparatus for controlling a motorized vehicle equipped with a main rechargeable battery, electrical loads electrically connected to the main rechargeable battery via a voltage converter, a converter operating point setter is configured to, when current is passing between the main rechargeable battery and the electrical loads, based on a charging/discharging amount of the main rechargeable battery, set operating points of the voltage converter, each specifying a power conversion efficiency representing a ratio of input power to the electrical loads to output power of the main rechargeable battery and an output current of the voltage converter. A converter controller is configured to, based on the operating point set by the converter operating point setter, cause the voltage converter to convert the voltage of the main rechargeable battery, thereby supplying power to the electrical loads.