Variable Speed Compressor Control for Vehicle Air Systems
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Solution Overview
Problem
The existing compressed air systems for motor vehicles consume excessive power, leading to increased fuel consumption and emissions, as they lack efficient control mechanisms to optimize compressor speed based on varying vehicle operations and air pressure levels.
Innovation Solution
A compressed air system with a controller that adjusts the electric drive motor's speed based on multiple signals, including accelerator pedal status, vehicle speed, temperature, wetness level, load, and power supply status, to minimize power consumption by optimizing compressor speed across different pressure intervals and operational modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the compressor runs at high speed to quickly charge the air reservoir, then the air pressure increases faster, but the power consumption increases significantly
Solution Approach 1:
The patent implements variable speed control of the compressor motor based on real-time pressure sensor feedback. The controller dynamically adjusts the motor speed according to the current pressure in the air reservoir, running at high speed only when pressure is low and reducing speed as pressure increases, thereby optimizing the balance between charging speed and power consumption.
Solution Approach 2:
The system changes the operating parameters (motor speed, power output) of the compressor based on the pressure level in the air reservoir. By monitoring pressure continuously and adjusting motor parameters accordingly, the system achieves efficient operation across different charging stages, reducing overall power consumption while maintaining adequate charging performance.
2Reliability
If the compressor operates continuously to maintain air pressure, then the air system reliability is improved, but the fuel consumption and emissions increase
Solution Approach 1:
The compressor operates periodically rather than continuously, based on pressure threshold detection. When the air reservoir pressure reaches a predetermined upper threshold, the controller stops the compressor motor. When pressure drops below a lower threshold, the motor restarts. This periodic operation maintains sufficient air pressure for reliable system operation while minimizing unnecessary running time, thereby reducing fuel consumption and emissions.
Solution Approach 2:
The system uses pressure sensors to continuously monitor the air reservoir pressure and feeds this information back to the controller. The controller uses this feedback to make intelligent decisions about when to start and stop the compressor, ensuring operation only when necessary to maintain pressure within the optimal range, thus balancing reliability with energy efficiency.
3Productivity
If the compressor speed is increased to meet high air demand, then the air supply capacity is improved, but the specific power consumption per unit mass of air increases
Solution Approach 1:
The motor speed is dynamically adjusted based on the current air demand and pressure conditions. Rather than operating at constant high speed, the controller modulates the motor speed to match the actual compression requirements, reducing specific power consumption while maintaining adequate air supply capacity through variable speed operation.
Solution Approach 2:
The system changes motor operating parameters (speed, torque) according to the compression requirements and pressure differential. By optimizing these parameters in real-time based on actual operating conditions, the system reduces specific power consumption per unit mass of air compressed while still meeting the required air supply capacity.
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 approach reduces power consumption, extends compressor lifespan, optimizes air reservoir capacity, and reduces frequent start-ups, thereby saving fuel and decreasing emissions while ensuring reliable air system operation.
Implementation Method 1
an electric drive motor, which can be controlled for variable speed
Implementation Method 2
an air compressor coupled to be driven by the electric drive motor
Data Source
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AI summary
The invention refers to a compressed air system (100) for a motor vehicle with an air supply system (200), comprising: - an electric drive motor (8), which can be controlled for variable speed, - an air compressor (9) coupled to be driven by the electric drive motor (8), - an electric power supply (6) for supplying electric power to the electric drive motor (8), - at least one air reservoir (11) connected with said air compressor (9) to receive air from the air compressor (9), - an air utilization system (300) connected to said at least one air reservoir (11) to receive air from said at least one air reservoir (11), - a controller (7) to control the speed of the electric drive motor (8). According to the invention, the controller (7) controls the electric drive motor (8) to determine the speed of the electric drive motor (8) in a way that during filling of the air reservoir (11), when the pressure level in the air reservoir (11) passes a setpoint that is between a minimum level and a higher cut off pressure level, the controller changes the compressor speed so that specific power consumption per unit mass of air compressed is decreased.