Electrical Vacuum Pump Soft Start Control via Current Sensing
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Solution Overview
Problem
Electrical vacuum pumps experience peak current generation during initial motor starting, leading to momentary voltage drops and noise issues, which existing hardware filter solutions address but at the cost of increased complexity and cost, and are not effective for various load peaks.
Innovation Solution
A control method for electrical vacuum pumps that adjusts motor input voltage based on sensed current using a current sensing circuit and a look-up table, implementing a soft start by time-dividing the motor start period and adjusting voltage to prevent peak current generation, allowing for independent control of external noise and compensation for voltage drops.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a hardware filter circuit is used to suppress peak current, then noise is reduced, but device complexity and cost increase
Solution Approach 1:
The patent replaces the hardware filter circuit (mechanical/electrical system) with a software-based control method. The controller uses current sensing to detect peak current conditions and dynamically adjusts motor input voltage through software logic, eliminating the need for physical filter components while achieving the same noise suppression effect.
Solution Approach 2:
The patent changes the voltage parameter dynamically based on detected current conditions. When peak current is detected, the controller adjusts the motor input voltage to a predetermined level, thereby controlling the current parameter to prevent noise without requiring additional hardware filters.
2Object-affected harmful factors
If a hardware filter circuit is used to suppress peak current, then noise is reduced, but manufacturing cost increases
Solution Approach 1:
The patent replaces expensive hardware filter components with software control logic that utilizes existing sensors and controllers. This substitution eliminates the need for additional filter capacitors, inductors, and associated circuitry, thereby reducing bill of materials cost and simplifying manufacturing processes.
Solution Approach 2:
The system uses its own existing current sensing capability and controller to detect and suppress peak current. Rather than requiring external filter hardware, the system serves its own noise suppression needs through intelligent control algorithms, eliminating the need for separate filter components and reducing manufacturing cost.
3Object-generated harmful factors
If motor input voltage is adjusted during starting, then peak current is prevented, but control complexity increases
Solution Approach 1:
The patent implements a feedback control mechanism where the controller continuously monitors motor current during starting and adjusts input voltage based on the detected current level. This closed-loop feedback approach prevents peak current by responding to actual operating conditions, using simple threshold-based logic rather than complex control algorithms.
Solution Approach 2:
The patent applies preliminary voltage adjustment before peak current can occur. The controller detects the starting condition and proactively adjusts the motor input voltage to a controlled level, preventing the development of peak current rather than reacting to it after it occurs. This preventive approach simplifies control logic compared to complex reactive systems.
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 method effectively prevents peak current generation, reduces noise, and enhances protection against overload, low voltage, and temperature fluctuations, enabling accurate and rapid digital noise control, while reducing hardware requirements and costs.
Implementation Method 1
sensing current applied to the motor using a current sensing circuit
Implementation Method 2
rotating a pump with the motor to generate vacuum
Data Source
AI summary
A control method and system of an electrical vacuum pump is provide to resolve generation of peak current when a motor of the electrical vacuum pump initially starts and implement a soft start. The electrical vacuum pump generates vacuum by suctioning air by rotating a pump with a motor. The control method includes starting the motor by supplying a power supply to the motor to switch on the electrical vacuum pump and sensing current applied to the motor using a current sensing circuit. In addition, the method includes determining a target value of motor input voltage set as a value according to the sensed applied current while starting the motor until the sensed applied current reaches a predetermined current and adjusted the motor input voltage applied to the motor to correspond to the target value.