Analog Motor Controller for High-Speed Three-Phase Drive
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Solution Overview
Problem
Existing motor controllers for three-phase motors require complex digital calculations, leading to inefficiencies at high rotational speeds due to circuit complexity and calculation lag.
Innovation Solution
A motor controller using an analog output system with a rotating magnetic field detected by magnetoresistive effect devices, generating sine and cosine waves to produce a linear angle detection output, allowing for simple circuit configuration and high-speed switching of three-phase driving power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If digital calculation is used to generate driving signals, then control precision is improved, but circuit complexity and calculation time increase
Solution Approach 1:
The patent replaces the digital calculation system (arithmetic processing unit) with an analog signal processing system. The analog mixer circuit directly processes sine and cosine waveforms from magnetic detectors to generate driving signals, eliminating the need for complex digital computation circuits while maintaining control precision through continuous analog signal processing.
Solution Approach 2:
The patent employs analog signal processing akin to fluid dynamics, where continuous analog waveforms flow through mixer circuits to generate driving signals. This analog approach allows simultaneous processing of multiple signals without the discrete step-by-step calculation delays inherent in digital systems, reducing circuit complexity while maintaining precision.
2Measurement precision
If digital calculation is used to generate driving signals, then control accuracy is improved, but calculation speed decreases
Solution Approach 1:
The patent substitutes digital calculation with analog signal processing using a mixer circuit that continuously processes sine and cosine waveforms. This analog approach enables real-time signal processing at speeds matching high rotational velocities, eliminating the calculation time delays inherent in digital systems while preserving control accuracy through continuous waveform manipulation.
Solution Approach 2:
The analog signal processing system maintains continuous operation without the discrete calculation cycles of digital systems. The mixer circuit continuously processes incoming sine and cosine waveforms to generate driving signals, ensuring uninterrupted control even at high rotational speeds where digital calculation cannot keep pace with the changing motor state.
3Device complexity
If analog signal processing is used, then circuit complexity is reduced, but measurement precision may decrease
Solution Approach 1:
The patent replaces complex digital calculation circuits with a simplified analog mixer circuit that processes sine and cosine waveforms. This analog substitution reduces circuit complexity significantly while maintaining measurement precision through the continuous nature of analog signal processing, which accurately reflects the physical motor state without digital quantization errors.
4Speed
If analog signal processing is used, then calculation speed is improved, but control complexity may increase
Solution Approach 1:
The patent substitutes complex digital control logic with a straightforward analog mixer circuit that naturally processes sine and cosine waveforms at high speeds. This analog approach achieves fast calculation speed matching high rotational velocities while actually reducing control complexity, as the analog circuit requires no programming, clock signals, or complex control logic inherent in digital systems.
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 smooth and accurate control of three-phase driving power at high rotational speeds with reduced ripple in rotation driving torque, maintaining synchronization with motor speed without the need for complex calculations.
Implementation Method 1
a rotating magnetic field, a first magnetic detector, a second magnetic detector, and an analog mixer. The rotating magnetic field is formed in accordance with the rotation of the rotation shaft. The first magnetic detector obtains a detected output analogous to a sine wave which is a rotation angle function for the rotating magnetic field.
Implementation Method 2
A motor controller using an analog output system with a rotating magnetic field detected by magnetoresistive effect devices
Data Source
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AI summary
The outputs from a first magnetic detector (11) and a second magnetic detector (12) are supplied to first to fourth output circuits (21, 22, 23, and 24) which are differential amplifiers, whereby detected outputs (S1 and S2) which are analogous to a sine wave and whose positive-negative polarities are opposite to each other, and detected outputs (S3 and S4) which are analogous to a cosine wave and whose positive-negative polarities are opposite to each other are obtained. The detected outputs (S1 to S4) are supplied to a switching circuit (31), and detected output portions are obtained at intervals of 90° from the detected outputs (S1 to S4). A bias adding circuit 33 applies a bias voltage to each of the detected output portions to obtain an angle detection output analogous to a linear function. The angle detection output is used to determine the supply timing at which a three-phase driving current is supplied.