Gradient Field Power Supply Transformer Winding Configuration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional gradient field power supplies in magnetic resonance imaging apparatuses experience voltage variations and offsets due to uneven loading on primary windings, leading to instability in output currents and voltage fluctuations, which can prevent imaging methods like echo planar imaging from being executed when voltage thresholds are exceeded.
Innovation Solution
The gradient field power supply apparatus is designed with a transformer configuration where the number of secondary windings is equal to or a multiple of the number of primary windings, with secondary windings of each phase wound around corresponding primary windings to distribute loads evenly and minimize voltage variations, and the secondary windings are arranged to reduce leakage magnetic fluxes and stabilize magnetic coupling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If single-phase secondary windings are wound around three-phase primary windings with uneven spatial arrangement, then the transformer can provide power to multiple channels, but offsets occur in loads on respective phases causing voltage variations
Solution Approach 1:
The patent divides the secondary windings into multiple single-phase windings for each channel (X, Y, Z channels have separate secondary windings). Each secondary winding is independently wound around corresponding primary windings, allowing independent control and loading for each channel while maintaining balanced phase distribution.
Solution Approach 2:
The patent applies different winding configurations to different channels based on their specific loading requirements. Each channel's secondary winding is optimally positioned and configured for its specific channel characteristics, allowing localized optimization of voltage stability for each output channel.
2Power
If output current is increased to improve imaging capability, then more power can be supplied to gradient coils, but voltage variations increase frequently
Solution Approach 1:
The patent incorporates voltage detection and feedback control mechanisms that monitor the output voltage of each channel and adjust the primary winding excitation accordingly. This feedback system maintains voltage stability even when output current is increased, preventing voltage excursions that would trigger interlocking.
Solution Approach 2:
The patent dynamically adjusts transformer operating parameters such as primary winding excitation current and switching frequency based on load conditions. When output current increases, the system modifies these parameters to maintain stable output voltage, allowing high power delivery without excessive voltage variation.
3Productivity
If echo planar imaging is executed with concentrated current in read channel, then imaging speed is improved, but offsets occur in respective phases causing voltage threshold exceedance
Solution Approach 1:
The patent segments the power supply into independent channel-specific secondary windings (Xch, Ych, Zch) that can be controlled separately. This allows the read channel to draw concentrated current for high-speed EPI imaging while the other channels maintain balanced loading, preventing phase offsets and voltage threshold violations.
Solution Approach 2:
The patent pre-configures the transformer with balanced multi-phase winding arrangements and includes protective control mechanisms that detect and prevent voltage excursions before they trigger interlocking. This cushioning approach ensures that even during high-current EPI sequences, voltage remains within safe operating thresholds.
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 configuration ensures stable power supply to gradient field coils, preventing disproportionate loading on primary windings and reducing voltage variations, allowing for reliable operation even with offsets in output currents between channels, thereby enabling consistent imaging without exceeding voltage thresholds.
Implementation Method 1
The power supply transformers in the gradient field power supply apparatus transform and distribute the three-phase 400-V power supplied to the gradient field power supply apparatus
Implementation Method 2
the secondary windings of the respective phases being wound around the primary windings of the respective phases
Data Source
AI summary
According to one embodiment, there is provided a magnetic resonance imaging apparatus in which a gradient field power supply apparatus supplies currents to gradient field coils corresponding to spatial coordinate axis directions to form gradient fields in a static field space which change along the respective spatial coordinate axis directions, the gradient field power supply apparatus includes a transformer configured to supply power supplied to a primary winding to a current output circuit via a plurality of secondary windings, with the number of phases of the primary windings being equal to or a multiple of the number of phases of the secondary windings, and the secondary windings of the respective phases of output channels corresponding to the respective spatial coordinate axis directions being wound around the primary windings of the respective phases.