Magnet Motor Power Conversion Control for Speed and Torque Pulsation
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Solution Overview
Problem
Existing technologies fail to effectively suppress both motor speed and torque pulsation, leading to unstable and inefficient control characteristics in compressor systems.
Innovation Solution
A power conversion device incorporating a first and second filter unit with varying transfer functions to compute torque and speed estimation values, allowing for precise control of motor torque and speed, using a magnet motor with a primary and secondary system transfer function filter to adjust control modes based on speed and torque pulsation components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a resonance filter is used to extract pulsating components for speed control correction, then motor speed pulsation is suppressed, but torque pulsation remains unaddressed leading to inefficient control characteristics
Solution Approach 1:
The control system is segmented into two independent filter units: a first resonance filter for speed pulsation suppression and a second resonance filter for torque pulsation suppression. Each filter operates independently to address specific pulsation sources, allowing simultaneous optimization of both speed stability and torque smoothness without interference between the two control objectives.
Solution Approach 2:
The dual-filter system provides multi-functionality by handling both speed control and torque control within a unified control architecture. The first filter unit processes speed-related pulsations while the second filter unit processes torque-related pulsations, creating a universal solution that addresses multiple control deficiencies simultaneously.
2Device complexity
If fixed transfer function filters are used in the control system, then the system structure is simple, but the control accuracy varies across different speed regions
Solution Approach 1:
The filter system transitions from static to dynamic operation by making the transfer functions variable based on operating conditions. The first and second transfer functions are dynamically adjusted according to the motor's speed region, allowing the filters to adapt their characteristics to match the pulsation patterns at different speeds, thereby maintaining high control accuracy across the entire operating range.
Solution Approach 2:
The transfer function parameters of both filter units are changed based on the operating speed region. By detecting the current speed range and selecting appropriate transfer function parameters, the system optimizes the filter characteristics for each specific operating condition, achieving accurate pulsation suppression whether the motor operates at low, medium, or high speeds.
Data Source
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AI summary
Provided is a power conversion device that realizes stable, highly accurate, and highly efficient control characteristics by suppressing pulsation in a speed of a driven motor and suppressing pulsation in torque. The power conversion device that drives a magnet motor includes: a first filter unit that includes a primary system transfer function filter that varies in correspondence with a pulsating component of the magnet motor, and computes a second speed estimation value from a speed command value and a first speed estimation value; a speed control unit that computes a first torque current command value from the speed command value and the second speed estimation value; and a second filter unit that includes a secondary system transfer function filter that varies in correspondence with the pulsating component, and computes a second torque current command value from the first torque current command value. Power to be supplied to the magnet motor is controlled on the basis of the second torque current command value.