Vehicle Air Compressor Speed Mapping for Demand-Based Efficiency
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Solution Overview
Problem
Conventional air compressors in heavy-duty vehicles driven by internal combustion engines lack control over compressor speed, leading to inefficient energy use, while electric motor-driven compressors are energy-intensive and inefficient due to unregulated operation.
Innovation Solution
A method to control the rotational speed of an electric motor-driven air compressor by determining efficient operating speeds based on pneumatic power production and consumption rates, using a control unit to adjust the compressor speed for optimal efficiency and energy savings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the air compressor is driven by an internal combustion engine, then the compressor speed depends on the engine speed, but the compressor cannot be controlled and runs at low efficiency speeds
Solution Approach 1:
The patent replaces the mechanical coupling between the internal combustion engine and the air compressor with an electric motor-driven system. This substitution allows the compressor to be decoupled from the engine's mechanical constraints and controlled independently through electrical means, enabling operation at optimal efficiency speeds regardless of engine speed.
Solution Approach 2:
The patent implements dynamic speed control of the electric motor-driven compressor based on real-time monitoring of compressed air consumption and storage tank pressure. The system continuously adjusts the compressor speed to match actual demand, allowing the compressor to operate dynamically at its most efficient speed points rather than at fixed engine-determined speeds.
2Ease of operation
If the air compressor is driven by an electric motor independent of the propelling motor, then the compressor speed can be controlled, but the energy consumption is very high
Solution Approach 1:
The patent implements a feedback control system that continuously monitors the pressure in the compressed air storage tank and the rate of air consumption by pneumatic systems. Based on this feedback, the control unit adjusts the electric motor speed to match actual compressed air demand, preventing energy waste by avoiding unnecessary compression when sufficient stored air is available.
Solution Approach 2:
The patent applies partial action by operating the compressor only when and to the extent needed to maintain adequate compressed air supply. The system determines minimum required compressor operation based on tank pressure levels and consumption rates, running the compressor at reduced speeds or idle periods when demand is low, rather than maintaining continuous high-speed operation.
3Reliability
If the compressor runs continuously to meet air demand, then adequate compressed air supply is maintained, but energy is wasted at low efficiency speeds
Solution Approach 1:
The patent implements dynamic speed adjustment of the electric motor-driven compressor based on real-time monitoring of compressed air consumption and storage tank pressure. The system continuously adapts the compressor speed to match actual demand, allowing the compressor to operate dynamically at its most efficient speed points rather than at fixed engine-determined speeds.
Solution Approach 2:
The patent changes the operating parameters of the compressor by controlling the electric motor speed across a range of values rather than running at fixed speed. The control unit adjusts rotational speed parameters based on tank pressure and consumption rate, enabling the compressor to operate at optimal efficiency points while maintaining reliable air supply.
Data Source
Figure 1~2
AI summary
A method for controlling the rotational speed (S) of an electric motor driven air compressor (2) that supplies compressed air to a pneumatically operated system (5) of a vehicle (1), characterized by the preliminary steps of: a) determining the efficiency (e) of the air compressor (2) for different values (Si) of the rotational speed (S) of the air compressor (2), the efficiency (e) of the air compressor (2) corresponding to the ratio between the pneumatic power (PI) produced by the air compressor (2) and the power (PO) given to the air compressor (2); b) determining one or several specific values (S2, S4) among said different values (Si), for which the efficiency (e) of the air compressor (2) is higher than a threshold value (emin) and/or comparatively higher than those determined for values (SI, S3) close to said specific value(s) (S2, S4); the preliminary steps a) and b) being preferably implemented only once; and characterized by the further repetitive steps of : c) determining the air consumption rate of the pneumatically operated system (5) receiving compressed air from the air compressor (2); d) determining a minimum rotational speed (Smin) of the air compressor (2) to obtain an air production rate of the air compressor (2) that is equal or substantially equal to said determined air consumption rate; e) determining if the specific value or one of the specific values (S2, S4) is greater than said determined minimum rotational speed (Smin); f) if no specific value is greater than said determined minimum rotational speed (Smin), controlling the rotational speed (S) of the air compressor (2) based on said minimum rotational speed (Smin); g) if only one specific value (S4) is greater than said determined minimum rotational speed (Smin), controlling the rotational speed (S) of the air compressor (2) based on said only one specific value (S4); h) if a plurality of specific values (S2, S4) is greater than said determined minimum rotational speed (Smin), determining the specific value (S2) with the best efficiency among said plurality of specific values (S2, S4) and controlling the rotational speed (S) of the air compressor (2) based on said specific value (S2) with the best efficiency.