Motor Phase Advance Control Without Current Sensing
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Solution Overview
Problem
Existing motor control systems require current detection and complex arithmetic processing to manage d-axis current, leading to inefficiencies and decreased efficiency and speed controllability when rotation speed and load fluctuate.
Innovation Solution
A motor control device and method that utilize a phase advance angle map to associate phase advance angle values with load factors, allowing for d-axis current control without current detection and complex arithmetic processing, using a storage unit, calculation unit, and drive control unit to set and control the phase advance angle based on the map.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If current detection and complex arithmetic processing are used to control d-axis current, then motor control precision is improved, but device complexity and processing requirements increase
Solution Approach 1:
The patent extracts the d-axis current control function from the complex vector control system by using phase advance angle control instead. This separates the control mechanism into a simpler form that achieves the same objective without requiring current detection or complex coordinate transformations.
Solution Approach 2:
The patent replaces the electrical measurement and computation-based control (current detection and arithmetic processing) with a phase angle-based control mechanism. This substitution eliminates the need for current sensors and complex calculation units while maintaining control effectiveness.
2Use of energy by moving object
If vector control with current detection is implemented, then motor efficiency is improved, but processing time and computational load increase
Solution Approach 1:
The patent pre-calculates and stores the relationship between phase advance angles and motor operating conditions (speed and load). This allows the control system to directly retrieve optimal phase angles from lookup tables without performing real-time complex calculations, thus reducing processing time while maintaining efficiency.
Solution Approach 2:
The patent creates a simplified control model that copies the essential behavior of vector control through phase advance angle adjustment. Instead of implementing the full vector control algorithm with its computational requirements, it uses a simplified approach that replicates the efficiency benefits without the processing overhead.
3Device complexity
If fixed phase advance angle is used to reduce complexity, then device complexity is reduced, but adaptability to load and speed changes deteriorates
Solution Approach 1:
The patent implements dynamic phase advance angle adjustment by storing multiple phase angle values in lookup tables corresponding to different motor speeds and load conditions. The control system dynamically selects the appropriate phase angle based on current operating conditions, enabling adaptability without increasing device complexity.
Solution Approach 2:
The patent changes the control parameter from a fixed phase advance angle to a variable phase advance angle that is selected based on motor speed and load factor. This parameter change allows the system to adapt to different operating conditions while maintaining simple control logic through lookup table retrieval.
Data Source
AI summary
A motor control device includes: a memory configured to store a phase advance angle map in which a phase advance angle map value and a load factor of a motor are associated in advance; a phase advance angle setting unit configured to calculate a load factor of the motor at a motor application voltage that is a voltage to be applied to the motor and set a phase advance angle calculated on the basis of a phase advance angle map value and the motor application voltage; and a PWM drive control unit configured to control the motor at the set phase advance angle. The phase advance angle map value is obtained from the phase advance angle map using the calculated load factor.