Motor Power Converter Phase Error Control Across Speed Ranges
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Solution Overview
Problem
Existing power conversion devices experience torque shock and inaccurate control characteristics when switching between low-speed and medium-to-high-speed ranges due to frequency differences, and require adjustments to electrical circuit parameters for stable operation.
Innovation Solution
A power conversion device that calculates first and second phase error estimates in different frequency domains, using reactive or active power deviations to adjust motor frequency and prevent torque shock without adjusting electrical circuit parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a large number of switching elements are arranged in series to handle high voltage, then the voltage handling capability is improved, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The power conversion device is divided into multiple independent modular units, each handling a portion of the total voltage. These modules can be connected in series to achieve high voltage operation while maintaining individual module simplicity. Each module contains its own switching elements arranged in series, but the modular architecture isolates the complexity within manageable units rather than requiring one large complex system.
Solution Approach 2:
The patent employs a hierarchical modular structure where identical or similar power conversion modules are nested or stacked together. Each module contains a complete set of switching elements, reactive elements, and control circuits. By nesting multiple such modules in series, the system achieves high voltage capability while reusing the same design template, thereby reducing overall manufacturing complexity through standardization.
2Power
If switching elements are arranged in series to handle high voltage, then the voltage handling capability is improved, but the loss of subharmonics and manufacturing precision become more difficult to control
Solution Approach 1:
By segmenting the high-voltage system into multiple modular units with identical switching element arrangements, the patent ensures that each module can be manufactured and tested independently with consistent precision standards. This segmentation allows for better control of manufacturing tolerances within each module while achieving the overall high-voltage capability through series connection of these precisely controlled units.
3Power
If switching elements and reactive elements are arranged in series, then the voltage handling capability is improved, but the device complexity and difficulty of detection and measurement increase
Solution Approach 1:
The segmentation into modular units allows each module to have its own measurement and detection circuits, simplifying the overall system. Instead of requiring complex measurement systems for the entire high-voltage series connection, each module can be independently monitored, and the results aggregated. This modular measurement approach reduces the difficulty of detecting and measuring electrical parameters in high-voltage systems.
4Power
If a large number of switching elements are used, then the power conversion capability is improved, but the device complexity and manufacturing cost increase
Solution Approach 1:
The patent uses identical or similar power conversion modules nested or stacked in series. Each module contains a standardized set of switching elements, reactive elements, and control circuits. This nesting approach allows for mass production of standardized modules, significantly improving ease of manufacture compared to building a custom large-scale system. The modular design enables parallel manufacturing of multiple modules that can then be assembled through simple series connections.
Solution Approach 2:
Each modular unit is designed as a universal building block that can be used in various configurations and applications. The standardized switching elements and reactive elements within each module serve multiple functions: voltage handling, power conversion, and even their own isolation and protection. This universality reduces the total number of different component types needed, simplifying manufacturing and inventory management while maintaining high power conversion capability.
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
Achieves stable and highly accurate control characteristics across speed ranges without requiring adjustments to electrical circuit parameters, preventing torque shock and ensuring precise motor operation.
Implementation Method 1
a first reactive element having a first first terminal and a first second terminal, and a second reactive element having a second first terminal and a second second terminal
Implementation Method 2
power conversion device includes a first switching element connected in series with a first reactive element, and a second switching element connected in series with a second reactive element
Data Source
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AI summary
A power conversion device comprising, a power converter that outputs signal to the motor to vary the motor's output frequency, output voltage and output current and control unit that controls the power converter, the control unit is, calculating the first power from the output voltage and output current, calculating the second power from the output current, electrical circuit parameters and frequency estimates, calculating the first phase error estimate so that the first power follows the second power in the first frequency domain, calculating the second phase error estimate different from the first frequency domain in a second frequency domain, controlling the frequency estimates so that the first phase error estimate or the second phase error estimate follows the command value of the phase error estimate.