Single-Phase Permanent Magnet Motor Control Equipment
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Solution Overview
Problem
Existing single-phase permanent-magnet brushless motors face issues with current peaks leading to mechanical stresses and demagnetization, and inefficient control of current as rotor speed varies, resulting in noise and vibration, which are not effectively addressed by known drive devices.
Innovation Solution
An electronic control equipment with a comparator block and modulation block that generates a control signal to adjust power transfer to the motor based on reference and current signals, using a low-pass filter and current sensor to limit current peaks and modulate power delivery, allowing efficient control across varying rotor speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the maximum phase current is limited by increasing the impedance of the coil, then current peaks are prevented, but the performance of the motor is reduced
Solution Approach 1:
The patent applies dynamic control by varying the impedance of the coil according to the rotor speed. At low speeds, the impedance is increased to prevent current peaks, while at high speeds, the impedance is decreased to maintain motor performance. This dynamic adjustment resolves the contradiction between preventing current peaks and maintaining motor performance across different operating conditions.
Solution Approach 2:
The patent changes the electrical parameter (impedance) of the coil based on operating conditions. By adjusting the impedance parameter dynamically according to rotor speed, the system prevents current peaks at low speeds while maintaining performance at high speeds, thus resolving the contradiction between reliability and productivity.
2Ease of operation
If known drive devices are used, then basic motor operation is achieved, but efficient control of current across varying rotor speeds is not possible, resulting in noise and vibration
Solution Approach 1:
The patent implements feedback control by continuously monitoring the rotor speed and adjusting the coil impedance accordingly. This feedback mechanism enables efficient current control across varying speeds, preventing noise and vibration while maintaining ease of operation. The system automatically adapts to different operating conditions without complex user intervention.
3Device complexity
If fixed impedance control is used, then simple control circuitry is maintained, but current control efficiency varies with rotor speed
Solution Approach 1:
The patent introduces dynamic impedance control that adapts to rotor speed variations. The control circuitry remains relatively simple while achieving efficient current control across different speeds through automatic adjustment of coil impedance based on feedback signals, thus resolving the contradiction between device complexity and productivity.
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
The solution effectively limits current peaks, reducing mechanical stress and noise, and enables efficient control of the motor at both high and low speeds, extending the range of controllable speed values and improving motor performance.
Implementation Method 1
using a low-pass filter and current sensor to limit current peaks and modulate power delivery
Implementation Method 2
An electronic control equipment with a comparator block and modulation block that generates a control signal to adjust power transfer to the motor based on reference and current signals
Implementation Method 3
modulation block that generates a control signal to adjust power transfer to the motor
Data Source
Figure 1
Figure 2A~5
Figure 3
AI summary
The present invention relates to an electronic control equipment (100) of the movement of a single-phase permanent-magnet electric motor (M) comprising: - a stage (101) for generating reference voltages; - a power stage (103) adapted to transfer electric power to the electric motor (M); - a control and adjustment stage (105) interposed between the stage for generating reference voltages (101) and the power stage (103). The control and adjustment stage (105) comprises a comparator block (107) adapted to generate a control signal (SC) to enable/disable the electric power transfer to the electric motor (M) based on the comparison of a first voltage signal (S1) and a second voltage signal (S2). Such control signal (SC) is a periodic signal having a first amplitude constant in a first time interval (T1) and a second amplitude variable linearly in a second time interval (T2). The control and adjustment stage (105) further comprises an electronic modulation block (109) of the control signal (SC) adapted to receive the control signal (SC) at a first input (1') and a modulation digital signal (Toc) at a second input (2') to generate a modulated control signal (SC1) at an output (3'). Such modulated control signal (SC1) having a further first amplitude constant in the first time interval (T1) to enable the electric power transfer to the electric motor (M), and having a further second amplitude, the average value of which is variable substantially linearly in a third time interval (T3) that is greater than said second time interval (T2) to disable the electric power transfer to the motor (M).