Vehicle Pump Motor Control via Rotor Period Monitoring
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Solution Overview
Problem
Electric motors in vehicle pumps experience torque fluctuations due to changes in viscosity and pressure, leading to loss of synchronization and control, particularly at low speeds, resulting in pump standstill and instability.
Innovation Solution
A method that determines the period of a partial revolution of the electric motor's rotor and adjusts its speed if the deviation from a predetermined value exceeds a minimum amount, using electromotive force measurements to monitor concentricity and stability, allowing for continuous operation and reduced instability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the electric motor operates at low speeds, then energy consumption is reduced, but torque fluctuations cause loss of synchronization and pump standstill
Solution Approach 1:
The control unit continuously monitors the period for partial revolution of the rotor and compares it with a predetermined comparison value. When deviation exceeds a minimum amount, the control unit adjusts the speed command to the electric motor, creating a closed-loop feedback system that maintains stable operation at low speeds without additional sensors.
Solution Approach 2:
The system dynamically adjusts the speed of the electric motor based on real-time monitoring of rotor period deviations. The control unit modifies the speed command continuously to maintain synchronization, allowing the motor to operate stably at varying low speeds rather than requiring a fixed minimum speed threshold.
2Productivity
If the pump operates with high hydraulic-mechanical rigidity, then pumping efficiency is improved, but torque requirements become highly sensitive to viscosity and pressure changes
Solution Approach 1:
The control unit proactively adjusts the speed command to the electric motor based on detected period deviations before complete desynchronization occurs. This preliminary corrective action prevents loss of control and maintains stable operation, allowing the pump to handle viscosity and pressure variations without compromising the high hydraulic-mechanical rigidity needed for efficient pumping.
3Measurement precision
If additional sensors are installed to monitor rotor position and speed, then control precision is improved, but device complexity and cost increase
Solution Approach 1:
The electric motor's control unit utilizes existing electrical signals and measurements already available in the system to determine the period for partial revolution of the rotor. By processing readily available electrical parameters, the system achieves precise monitoring and control without requiring additional mechanical sensors, thereby maintaining control precision while avoiding increased device 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
This method ensures stable operation of the electric motor by adjusting speed to maintain smooth running, reducing the risk of pump standstill and increasing overall stability, without the need for additional sensors, thus enhancing the reliability and efficiency of the pump.
Implementation Method 1
determining a period for at least one partial revolution of a rotor of the electric motor
Data Source
Figure 1~2
Figure 3~5
AI summary
The invention relates to a method for controlling an electric motor of a vehicle pump used to deliver a medium. According to said method, first a period required for at least one partial revolution of a rotor of the electric motor is determined. The fluctuations during said period can represent a measurement of the true running of the electric motor. The speed of the electric motor can be altered subsequently depending on the deviation of the period from a comparative value. As a result, the true running of the electric motor can be guaranteed once again.