Fluid Pump Motor Control for Precise Low-Speed Dosing
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Solution Overview
Problem
Existing fluid conveying devices struggle to operate efficiently at speeds below a threshold, limiting their ability to provide small, precise quantities of fluid to consumers like internal combustion engines or exhaust gas post-treatment systems.
Innovation Solution
A method involving rotating-speed-dependent control and step-by-step operation of an electric motor, particularly a permanently excited synchronous machine, using position sensors like Hall sensors to manage the motor's speed and position, allowing precise fluid conveyance even at low speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the electric motor is operated below the threshold speed, then the fluid conveying device can provide small quantities of fluid to the consumer, but the motor cannot be efficiently controlled at these low speeds using conventional rotating-speed-dependent control methods
Solution Approach 1:
The control range of the electric motor is segmented into two distinct zones: a first control range (above threshold speed) using rotating-speed-dependent control, and a second control range (below threshold speed) using step-by-step control. This segmentation allows each control method to operate optimally within its designated speed range, solving the problem of inefficient conventional control at low speeds while enabling precise fluid quantity delivery.
2Productivity
If rotating-speed-dependent control is used, then the motor operates efficiently at higher speeds, but it cannot achieve precise control at speeds below the threshold value
Solution Approach 1:
The control system dynamically adapts its operation mode based on the motor's speed range. At higher speeds, rotating-speed-dependent control maintains efficiency, while at lower speeds, step-by-step control provides precise positioning. The transition between control modes is managed dynamically, allowing the system to maintain both efficiency and precision across the entire operating range.
3Measurement precision
If step-by-step operation is implemented for low speed control, then precise fluid conveyance is achieved, but the system complexity increases due to the need for additional control mechanisms
Solution Approach 1:
The electric motor serves multiple functions: it operates as a conventional rotating-speed-dependent motor for high-speed efficient operation and as a stepper motor for low-speed precise positioning. This multi-functionality eliminates the need for separate control systems for different speed ranges, reducing overall system complexity while achieving precise fluid conveyance at low speeds.
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
Enables fluid conveying devices to operate at speeds below the threshold, ensuring accurate and efficient delivery of small fluid quantities to consumers, with features like error compensation ensuring precise fluid control and reduced power consumption.
Implementation Method 1
at least one position sensor, in particular at least one Hall sensor
Data Source
AI summary
A fluid conveying device and a method for operating a fluid conveying device, the fluid conveying device having an electric motor which for driving a pump stage is operatively connected to the latter, the method includes: a) rotating-speed-dependent controlling of the electric motor when the actual speed of the electric motor corresponds to at least one threshold value, b) step-by-step operation of the electric motor when the actual speed of the electric motor corresponds to a value below the threshold value.