Phase Shift Double Forward Converter Circuit for Welding Power Supply
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Welding and cutting power supplies face inefficiencies due to the need for oversized components to handle dynamic load requirements, which are not met by traditional single or double forward converter circuits, leading to inefficiencies during average operating conditions.
Innovation Solution
The implementation of a phase shift double forward converter circuit system that dynamically adjusts output voltage by manipulating duty cycles and phase shifts in response to voltage demands, using a controller to generate pulse width modulation signals and accommodate transformer core reset times through leading or lagging edge compensation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional single or double forward converter circuits are used to handle dynamic load requirements, then the power supply can meet transient voltage and current demands, but the components become oversized and efficiency decreases during average operating conditions
Solution Approach 1:
The power supply is divided into two separate forward converter circuits operating in parallel, each handling a portion of the load. This segmentation allows each circuit to be optimized for specific operating conditions, enabling efficient handling of both average and dynamic loads without requiring oversized components in a single circuit.
Solution Approach 2:
The system dynamically adjusts the operating state of the two forward converter circuits based on load conditions. During average loading, both circuits operate synchronously at reduced duty cycles for efficiency. During transient dynamic loads, the system shifts to phase-shifted operation where one circuit can operate at higher duty cycle while the other provides support, enabling rapid response to voltage and current demands.
2Adaptability or versatility
If components are sized to handle short but extreme dynamic requirements, then transient voltage and current demands are met, but the circuit has oversized components that reduce efficiency at average conditions
Solution Approach 1:
By segmenting the power supply into two forward converter circuits, each circuit can be sized for average load conditions rather than peak dynamic conditions. The coordinated operation of both circuits provides the necessary adaptability to handle extreme transient requirements without requiring individual components to be oversized.
Solution Approach 2:
Each forward converter circuit is designed to perform multiple functions: during average operation, both circuits share the load efficiently; during dynamic transients, either circuit can be rapidly adjusted to provide additional voltage or current support. This multi-functionality eliminates the need for specialized oversized components while maintaining adaptability.
3Ease of operation
If the duty cycle of forward converter circuits is increased to meet higher output voltage demand, then the transformer core must be given sufficient time to reset, which limits the maximum duty cycle
Solution Approach 1:
The use of two forward converter circuits allows the system to achieve higher effective duty cycles by operating the circuits in a phase-shifted manner. While one circuit is in its reset phase, the other can be in its active phase, effectively doubling the available duty cycle range without extending the reset time of individual transformer cores.
Solution Approach 2:
The system employs periodic phase-shifting of the two forward converter circuits, where each circuit operates in alternating phases. This periodic action allows the transformer cores to reset during the off-phase of their respective circuits while the other circuit remains active, enabling extended effective duty cycle operation without compromising core reset requirements.
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 solution allows for efficient handling of both static and dynamic load requirements, reducing component size and improving efficiency by dynamically adjusting voltage and current output to match transient demands without compromising average load performance.
Implementation Method 1
a first forward converter circuit and a second forward converter circuit
Data Source
AI summary
A technique for dynamically adjusting an output voltage for a welding or cutting operation is provided. The technique allows for varying output voltage at the welding or cutting torch by manipulating the duty cycles of two forward converter circuits. The present disclosure provides methods and systems for increasing synchronized duty cycles in a pair of forward converter circuits in response to increasing output voltage demand then changing a phase shift between the duty cycles in response to further increases in output voltage demand. The present disclosure provides a controller designed to receive input signals and generate output pulse width modulation signals that control the duty cycle width and phase shift of the outputs of the forward converter circuits in response to these signals. Methods of accommodating for the time needed for the transformer core to reset via leading edge or lagging edge compensation are provided.