Vehicle AC Compressor Drive via Hybrid Electric Machine
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Solution Overview
Problem
Existing air-conditioning systems for industrial vehicles face challenges in providing adequate cooling during vehicle stops, as they struggle to reconcile the power requirements of electric motors with the need to conserve battery power and optimize energy use.
Innovation Solution
An air-conditioning system that incorporates a main internal combustion engine, a refrigeration circuit, an alternating current electric machine, and a clutch system allowing the compressor to be driven by either the engine or the electric machine, with a control unit to manage energy conversion and storage, enabling efficient operation using high-efficiency batteries and reducing fuel consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If an auxiliary generator set with internal combustion engine is used to provide power during vehicle stops, then air-conditioning power availability is improved, but device complexity and fuel consumption increase
Solution Approach 1:
The electric machine is designed to perform multiple functions: it can operate as a motor to drive the compressor during vehicle stops, as a generator to charge batteries during vehicle operation, and as an engine brake. This multi-functionality eliminates the need for a separate auxiliary generator set, reducing system complexity while maintaining air-conditioning power availability during stops.
Solution Approach 2:
The patent combines the auxiliary power function with the existing electric machine that is already part of the hybrid powertrain system. By merging the air-conditioning drive function into the existing electric machine rather than adding a separate auxiliary generator set, the system achieves power availability during stops without increasing overall device complexity.
2Power
If a high-power electric motor is used to drive the compressor during stops, then air-conditioning performance is improved, but battery dimensions and cost increase
Solution Approach 1:
The electric machine charges the batteries during vehicle operation phases before stops occur. This preliminary charging action ensures that sufficient energy is stored in the batteries to power the compressor during subsequent vehicle stops, allowing high air-conditioning performance without requiring excessively large battery capacity.
Solution Approach 2:
The system maintains continuous energy availability by having the electric machine charge batteries during vehicle operation and then using those charged batteries to power the compressor during stops. This continuous cycle of charging and discharging ensures adequate power for air-conditioning without requiring the batteries to be oversized to handle peak demand alone.
3Loss of energy
If the electric machine is used as a generator during vehicle operation, then energy recovery is improved, but control complexity increases
Solution Approach 1:
The electric machine serves as both a motor and generator within the same hybrid powertrain system. When functioning as a generator during vehicle operation, it recovers energy to charge batteries. The existing control systems for hybrid powertrains are adapted to manage this dual functionality, avoiding the need for separate dedicated control systems and reducing overall control complexity.
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
The system ensures reliable air-conditioning during vehicle stops by optimizing energy use, reducing fuel consumption, and allowing the electric machine to function as a generator or motor, effectively managing power distribution and storage.
Implementation Method 1
an alternating current electric machine (7), preferably a brushless synchronous or asynchronous machine; it can also function as a generator
Implementation Method 2
the evaporator 6 is suitable to remove heat from the cab of a vehicle thanks to the evaporation of said fluid
Data Source
Figure 1
AI summary
Air-conditioning system for a vehicle, preferably an industrial vehicle, said system comprising: a main internal combustion engine (1); an alternating current electric machine (7) suitable to function as a motor and/or generator; a refrigeration circuit (2) comprising a compressor (3), suitable to be driven by said main engine or by said electric machine; a source (8) of electric power suitable to supply said electric machine characterized by comprising three clutches (10, 11, 12) suitable for independently connecting/disconnecting said main engine to said compressor, to said electric machine or said compressor to said electric machine. Vehicle equipped with said system.