Motor Driving Device Filter Switching for Position Detection
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Solution Overview
Problem
Existing motor driving devices face challenges in simultaneously achieving initial position determination and high-speed rotation driving of a permanent-magnet synchronous motor, as they often use the same circuit configuration for both processes, leading to inefficiencies.
Innovation Solution
A motor driving device that employs a filter part with two filters of different filter constants, using a larger filter constant for initial position determination and a smaller filter constant for rotation driving, allowing for effective detection of the rotor's initial position and smooth high-speed rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the same circuit configuration is used for both initial position determination and high-speed rotation driving, then device complexity is reduced, but it becomes difficult to achieve both processes effectively
Solution Approach 1:
The filter constant is dynamically switched between two values (first filter constant for initial position determination, second filter constant for high-speed rotation driving) based on the operational phase. This dynamic adjustment allows the same circuit to adapt to different process requirements, resolving the contradiction between device simplicity and process compatibility.
Solution Approach 2:
The filter constant parameter is changed between two discrete values depending on the operational mode. During initial position determination, a first filter constant is used, and during high-speed rotation driving, a second filter constant is used. This parameter switching enables the circuit to perform both functions effectively without increasing overall device complexity.
2Measurement precision
If a filter with a large filter constant is used for initial position determination, then measurement precision is improved, but it may not be suitable for high-speed rotation driving
Solution Approach 1:
The filter constant is dynamically adjusted based on the operational phase. A larger first filter constant is used during initial position determination to improve measurement precision, while a smaller second filter constant is used during high-speed rotation driving to maintain responsiveness. This dynamic switching resolves the contradiction between measurement precision and adaptability.
Solution Approach 2:
The filter constant parameter is switched between a first value (larger) for initial position determination and a second value (smaller) for high-speed rotation driving. This parameter change allows the system to optimize performance for each specific process requirement without compromising the other.
3Speed
If a filter with a small filter constant is used for high-speed rotation driving, then response speed is improved, but it may reduce measurement precision for initial position determination
Solution Approach 1:
The filter constant is dynamically switched to a smaller second filter constant during high-speed rotation driving to improve response speed, and to a larger first filter constant during initial position determination to ensure measurement precision. This dynamic adaptation resolves the contradiction between speed and precision.
Solution Approach 2:
The filter constant parameter is changed between a second value (smaller) for high-speed rotation driving and a first value (larger) for initial position determination. This parameter switching enables the system to achieve both fast response during rotation and high precision during position detection.
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
Enables both initial position determination and high-speed rotation driving processes to be performed efficiently, improving the overall performance of the motor driving device by optimizing filter usage based on the specific requirements of each process.
Implementation Method 1
a comparator to which the voltage signal is inputted through the filter part including a first filter and a second filter. When the initial position determination process of the rotor is performed in the filter part, the first filter whose filter constant is larger is selected. Further, when the rotation driving process is performed, the second filter whose filter constant is smaller is selected.
Data Source
AI summary
An initial position determination process and a rotation driving process are both attained. A motor includes a rotor having a permanent magnet with a plurality of magnetic poles and a stator having coils with a plurality of phases. A voltage signal generation part generates a voltage signal corresponding to an electric current flowing through each of the coils with the phases of the stator. A filter part includes a first filter and a second filter. The voltage signal is inputted to a comparator through the filter part. A control part controls such that the first filter whose filter constant is larger is selected when performing the initial position determination process of the rotor and the second filter whose filter constant is smaller is selected when performing the rotation driving process.