Brushless DC Motor Controller for Electric Pump Current Management
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Solution Overview
Problem
Existing electric pumps face issues with excessive current supply when motor load increases, leading to potential motor overload and reduced rotation speed due to constant voltage control and current feedback control methods.
Innovation Solution
An electric pump with a controller that switches between voltage control and current control based on target values, using a brushless DC motor and a sensorless-type configuration, sets upper and lower limits for FET driving duty ratios to manage current supply effectively, preventing excessive current and maintaining efficient operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If constant voltage control is used to maintain voltage value constant, then voltage control effectiveness is improved, but current value may exceed allowed current when load increases
Solution Approach 1:
The controller dynamically switches between voltage control and current control modes based on motor operation conditions. When the motor operates in a high-load region, the controller transitions from constant voltage control to constant current control, thereby adapting the control strategy to prevent excessive current while maintaining voltage control effectiveness in normal operating conditions.
2Object-affected harmful factors
If current feedback control is used to suppress current consumption, then current control is improved, but rotation speed becomes lower and motor may step out
Solution Approach 1:
The controller dynamically adjusts the control mode based on motor operation conditions. When the motor operates in a low-load region, the controller uses voltage control to maintain higher rotation speeds. When the motor operates in a high-load region, the controller switches to current control to suppress current consumption, thereby preventing motor step-out. This dynamic switching resolves the contradiction between current suppression and rotation speed maintenance.
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 solution allows for continuous and efficient current supply to the motor, preventing overload and maintaining high rotation speeds even under varying loads, while ensuring effective voltage control without sacrificing performance.
Implementation Method 1
The motor is a brushless direct-current (DC) motor and is configured to rotationally drive the pump unit
Data Source
AI summary
An electric pump includes a pump unit, a motor and a controller. The pump unit is configured to pump fluid by a rotating operation. The motor is a brushless direct-current motor and configured to rotationally drive the pump unit. The controller is configured to control a current to be supplied to the motor. The controller is configured to switch between voltage control for controlling the current to be supplied to the motor based on a target voltage and current control for controlling the current to be supplied to the motor based on a target current.