Motor Control Device Rotor Position Detection
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Solution Overview
Problem
Existing rotor position detection methods for synchronous motors without sensors suffer from varying accuracy and require high processing loads, necessitating advanced data processing apparatuses.
Innovation Solution
A motor control device that detects rotor position by using current and induced voltage peak values and electrical angles, directly finding the rotor position from predefined data tables containing current or induced voltage phases as variables, reducing the need for high-performance processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional rotor position detection methods are used (correcting virtual rotor position), then rotor position can be detected, but detection accuracy varies and processing load is high
Solution Approach 1:
The patent extracts only the essential parameters (current peak value, induced voltage peak value, and their electrical angles) needed for rotor position detection, eliminating the need for complex virtual position correction processes. This simplifies the data processing apparatus while maintaining detection accuracy by focusing on direct measurement of key electrical characteristics.
Solution Approach 2:
The patent pre-calculates and stores the relationship between electrical angles and rotor positions in lookup tables during the design phase. During operation, the system simply retrieves pre-computed values based on measured electrical angles, eliminating the need for real-time complex calculations and reducing processing load while ensuring consistent detection accuracy.
2Speed
If high-speed rotor position detection is implemented, then detection speed improves, but processing load increases requiring high-performance apparatus
Solution Approach 1:
The patent pre-computes rotor position values corresponding to various electrical angles and stores them in lookup tables before operation. During high-speed detection, the system only needs to measure current and voltage peaks, determine their electrical angles, and retrieve pre-calculated rotor positions from tables, enabling fast detection without heavy real-time processing demands.
Solution Approach 2:
The patent creates simplified copies of the complex rotor position calculation problem by pre-computing and storing representative solutions in lookup tables. Instead of performing full calculations during operation, the system uses these pre-computed copies, which can be retrieved instantly, thereby achieving high detection speed with minimal processing load.
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 accurate rotor position detection under lower processing loads, eliminating the requirement for high-performance data processing apparatuses and improving detection reliability.
Implementation Method 1
current detecting means for detecting a current flowing through a coil of the synchronous motor
Implementation Method 2
applied voltage detecting means for detecting an applied voltage applied to the coil of the synchronous motor
Implementation Method 3
induced voltage peak value and electrical angle detecting means for detecting an induced voltage peak value and an induced voltage electrical angle on the basis of the current detected in the current detecting means and the applied voltage detected in the applied voltage detecting means
Data Source
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AI summary
PROBLEMS TO BE SOLVED To provide is a motor control device capable of detecting a rotor position of a synchronous motor under a certain accuracy and a low processing load. MEANS FOR SOLVING THE PROBLEMS The motor control device detects the rotor position θm by directly finding a rotor position θm from a rotor position expression (θm = θi - β - 90°) containing, as a variable, a current electrical angle θi from among a phase current peak value Ip and a phase current electrical angle θi detected in a phase current peak value and electrical angle detection unit 19 and an induced voltage peak value Ep and an induced voltage electrical angle θe detected in an induced voltage peak value and electrical angle detection unit 20, and containing, as a variable, a current phase P capable of being selected using [a phase current peak value Ip] and [an induced voltage electrical angle θe - a phase current electrical angle θi] as parameters from a predefined data table.