Hydraulic Brushless Motor Control via Dynamic Conduction Timing
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Solution Overview
Problem
Conventional methods for controlling brushless motors in hydraulic pumps struggle to achieve the required output points for both high torque low rotation at low oil temperatures and low torque high rotation at high oil temperatures, due to limitations in current consumption and size, especially when using the 60 degrees conduction method.
Innovation Solution
The method involves detecting oil temperature or motor current to advance the conduction start timing of switching elements, allowing for dynamic adjustment of conduction timing to optimize torque and rotation speed, with the conduction start timing being advanced by 0 to 30 degrees based on temperature or current thresholds, ensuring high torque at low oil temperatures and returning to standard timing at higher temperatures or currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the conduction start timing is advanced to increase torque output, then high torque is achieved at low temperatures, but rotation speed decreases and energy consumption increases
Solution Approach 1:
The patent applies dynamics by making the conduction start timing adjustable rather than fixed. The control device dynamically changes the conduction start timing based on detected rotation speed and temperature conditions, allowing the system to optimize between torque and rotation speed according to actual operating requirements
Solution Approach 2:
The patent changes the conduction start timing parameter based on temperature and rotation speed conditions. When temperature is low and rotation speed is high, the conduction start timing is advanced to increase torque output. When temperature is high or rotation speed is low, the timing returns to standard to maintain efficiency
2Power
If the motor size is enlarged to satisfy both high torque low rotation and low torque high rotation requirements, then both output points are satisfied, but the motor becomes larger and more expensive
Solution Approach 1:
The patent uses parameter changes in the conduction timing to expand the operational range of the existing motor size. By adjusting the conduction start timing based on temperature and rotation speed, the motor can deliver both high torque at low temperatures and maintain efficiency at high temperatures without requiring physical enlargement
Solution Approach 2:
The dynamic adjustment of conduction timing allows a single motor design to adapt to different operational requirements, eliminating the need for multiple motor sizes or a larger motor design to cover all operating conditions
3Force
If the conduction timing is constantly advanced to maintain high torque output, then high torque is achieved, but rotation speed becomes too low for high temperature operation
Solution Approach 1:
The patent changes the conduction start timing parameter based on temperature detection. When oil temperature exceeds a predetermined threshold, the control device returns the conduction start timing to the standard value, preventing excessive torque that would cause rotation speed to drop too low for high temperature operation
Solution Approach 2:
The control device uses feedback from temperature detection to adjust the conduction timing. The detected oil temperature feeds back to the control logic, which then determines whether to advance or maintain standard conduction timing, creating a closed-loop control system
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 allows for consistent output performance across varying temperature conditions, achieving high torque at low oil temperatures and matching output at higher temperatures, while maintaining efficient energy use and motor size constraints.
Implementation Method 1
The controlling device of the brushless motor is configured by a motor with magnetic coils of three phases, the U phase, the V phase and the W phase; and a switching circuit including six switching elements for driving the motor. The operation of the brushless motor is performed by sequentially switching the switching element for conduction to the magnetic coils of three phases.
Data Source
AI summary
The method for controlling the hydraulic brushless motor operates the hydraulic brushless motor by switching the conduction timing to a plurality of switching elements. The method for controlling the hydraulic brushless motor includes detecting the oil temperature and advancing the conduction start timing when the oil temperature is lower than or equal to a predetermined value.