Hybrid Vehicle Compressor Control for Thermal Load and Battery Drain

Solution Overview

Problem

Hybrid vehicle air conditioning systems with electric compressors face inefficiencies in fuel usage due to thermal inertia, leading to slower indoor temperature changes and reduced compressor operation efficiency.

Innovation Solution

A vehicle control apparatus and method that determines thermal load levels based on engine state changes and battery discharge rates to adjust the electric compressor's operation, using a controller to calculate and apply control values for the compressor's duty ratio, holding time, and prohibition time to optimize energy use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the electric compressor operates continuously to maintain indoor temperature, then the indoor temperature comfort is improved, but the battery power consumption increases

Engineering Contradiction:

Improveindoor temperatureVSAvoidbattery power consumption

Core Design Contradiction:

TemperatureVSUse of energy by moving object

Solution Approach 1:

The control method implements periodic operation of the electric compressor by alternating between operating periods and stopping periods. The compressor operates for a predetermined time to reduce thermal load, then stops for a predetermined time to conserve battery power, creating a cyclic operation pattern that balances temperature maintenance with energy conservation.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The system performs preliminary cooling or heating action by operating the compressor for a predetermined time to reduce thermal load before stopping. This advance action prepares the thermal environment so that the compressor can be stopped while still maintaining acceptable temperature conditions, thereby reducing overall power consumption.

Inventive Principle:

Principle #10Preliminary action

2Use of energy by moving object

If the electric compressor operates intermittently to reduce power consumption, then the battery power consumption is reduced, but the indoor temperature response becomes slower

Engineering Contradiction:

Improvebattery power consumptionVSAvoidindoor temperature response speed

Core Design Contradiction:

Use of energy by moving objectVSSpeed

Solution Approach 1:

The control method implements periodic operation of the electric compressor by alternating between operating periods and stopping periods. The compressor operates for a predetermined time to reduce thermal load, then stops for a predetermined time to conserve battery power, creating a cyclic operation pattern that balances temperature maintenance with energy conservation.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The system maintains continuous thermal management effectiveness by carefully designing the operating and stopping periods to ensure that cooling or heating effects persist throughout the cycle. The compressor operates long enough to establish thermal effects that continue during the stopping period, ensuring continuous temperature control without constant operation.

Inventive Principle:

Principle #20Continuity of useful action

3Productivity

If the compressor operating time is extended to improve cooling/heating efficiency, then the thermal load control is improved, but the battery discharge rate increases

Engineering Contradiction:

Improvecooling/heating efficiencyVSAvoidbattery discharge rate

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The control method implements periodic operation of the electric compressor by alternating between operating periods and stopping periods. The compressor operates for a predetermined time to reduce thermal load, then stops for a predetermined time to conserve battery power, creating a cyclic operation pattern that balances temperature maintenance with energy conservation.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The system applies partial action by operating the compressor for a predetermined time that is sufficient to reduce thermal load but not necessarily to complete cooling or heating. This partial operation achieves adequate thermal management while limiting power consumption and battery discharge rate.

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS11993133B2Vehicle control apparatus and vehicle control method

Publication Date: 2024.05.28 HYUNDAI MOTOR CO LTD

AI summary

Vehicle control apparatus and vehicle control method are described. The vehicle control apparatus may include a compressor and a controller. The controller may determine a thermal load level at one or more of: a first time point at which an engine is switched to an ON state from an OFF state, a second time point at which a first discharge amount of the battery exceeds a first reference value while the engine is in the OFF state, or a third time point at which a second discharge amount of the battery exceeds a second reference value smaller than the first reference value and a discharge rate associated with the battery exceeds a third reference value while the engine is in the OFF state. The controller may control the compressor using a control value corresponding to the thermal load level.