Phase-Shifted Transformer Drive for Lower Primary Current Ripple
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Solution Overview
Problem
Existing power supply devices using multiple transformers experience significant current ripples on the primary side, leading to increased size requirements for filter circuits to smooth out these ripples.
Innovation Solution
The power supply device drives transformers with phase-differentiated transformer drive signals, breaking up the timing of current ripples across transformers, thereby reducing the maximum amplitude of these ripples and minimizing the size of the filter circuit needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If multiple transformers are driven by the same switching control signals, then the power supply device can operate efficiently, but the amplitude of current ripples on the primary side becomes large
Solution Approach 1:
The patent applies periodic action by introducing phase shifts between the switching control signals for different transformers. Specifically, the first switching control signal has a different phase than the second switching control signal, causing the transformers to operate in a staggered periodic manner. This distributes the current ripple occurrences over time, reducing the peak amplitude of combined current ripples on the primary side while maintaining continuous power supply operation.
2Object-generated harmful factors
If a filter circuit is added to suppress current ripples, then the amplitude of current ripples decreases, but the size of the filter circuit increases
Solution Approach 1:
The patent applies preliminary action by preemptively reducing current ripple amplitude through phase-shifted switching control signals before the current reaches the filter circuit. By distributing the ripple occurrences in time through phased operation of multiple transformers, the peak ripple amplitude is reduced in advance, which allows the filter circuit to be smaller while still achieving the required ripple suppression performance.
3Device complexity
If the filter circuit size is reduced, then the device complexity decreases, but the ability to smooth voltage effectively is compromised
Solution Approach 1:
The patent applies preliminary action by reducing current ripple amplitude through phase-shifted control before voltage smoothing is needed. This preliminary ripple reduction ensures that even with a smaller filter circuit, the voltage smoothing capability remains effective because the filter has less ripple amplitude to contend with, maintaining reliability while reducing device complexity.
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 reduces the amplitude of current ripples on the primary side, resulting in a smaller filter circuit and improved efficiency in smoothing voltage, while also reducing electromagnetic noise and wiring complexity.
Implementation Method 1
a plurality of transformers L each including a primary-side coil Lp and a secondary-side coil Ls coupled to the primary-side coil Lp in an electrically isolated state
Data Source
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AI summary
An amplitude of current ripples on a primary side of a power supply device that uses a plurality of transformers is reduced. A driving power supply device (7) that supplies electric power to a plurality of drive circuits (2) that individually drive switching elements (3) of an inverter (10) includes a plurality of transformers (L) having secondary-side coils (Ls) which are individually connected to the respective corresponding drive circuits (2); a plurality of transformer driving units (5) each including a driving switching element (M) that controls supply of electric power to a primary-side coil (Lp); and a power supply control device (6) that provides transformer drive signals (MG) for driving the transformer driving units (5). The power supply control device (6) drives the transformer driving units (5) by transformer drive signals (MG) having different phases.