LLC Resonant Converter Segmented Primary Winding for Wide Voltage Range
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
LLC resonant power converter apparatuses face challenges in generating a wide range of output voltages efficiently due to increased iron and copper losses in transformers and switch elements when operating over a wide range of switching frequencies.
Innovation Solution
The apparatus employs a configuration with multiple leg circuits, capacitors, and transformers, where the primary winding of the transformer is connected to nodes between switch circuits in leg circuits, allowing for selective operation of LLC resonant circuits with different capacitances and inductances to adjust switching frequency and output voltage, thereby minimizing losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If the switching frequency is decreased to generate higher output voltage, then the output voltage increases, but the iron loss in the transformer core increases
Solution Approach 1:
The patent divides the primary winding into multiple segments and connects them through different circuit paths with varying inductances. By selectively activating different segments and paths, the system can operate at different effective switching frequencies to generate various output voltages while minimizing iron loss at each operating point.
Solution Approach 2:
The patent employs dynamic switching between different circuit configurations (different inductance values) based on the required output voltage. This dynamic reconfiguration allows the system to adapt the switching frequency and inductance combination to maintain optimal efficiency across a wide output voltage range, preventing excessive iron loss.
2Shape
If the switching frequency is increased to generate lower output voltage, then the output voltage decreases, but the copper loss in transformer windings increases
Solution Approach 1:
The primary winding is segmented into multiple sections with different inductances. By selectively connecting different segments in series or parallel, the system can adjust the effective inductance to match the required switching frequency, thereby reducing copper loss when operating at higher frequencies for lower output voltages.
Solution Approach 2:
The patent changes the effective inductance parameter by reconfiguring the circuit paths connecting different primary winding segments. This parameter adjustment allows the system to optimize the balance between switching frequency and inductance, reducing copper loss while maintaining the desired output voltage.
3Loss of energy
If the transformer size is increased to reduce iron loss and copper loss, then the losses are reduced, but the device complexity and size increase
Solution Approach 1:
Instead of using a single large transformer, the patent segments the primary winding into multiple smaller sections that can be reconfigured. This segmentation allows the use of a smaller overall transformer while achieving the same loss reduction effect through optimal switching frequency selection and inductance matching.
Solution Approach 2:
The patent makes the transformer primary winding multi-functional by enabling it to operate in different configurations (different inductance values) for different output voltage requirements. This multi-functionality allows a single smaller transformer to replace what would traditionally require a larger transformer to handle the full range of operating conditions efficiently.
4Shape
If the switching frequency is increased to generate lower output voltage, then the output voltage decreases, but the losses in switch elements increase
Solution Approach 1:
The system dynamically adjusts the circuit configuration to change the effective switching frequency and inductance based on the required output voltage. By doing so, it avoids operating switch elements at excessively high frequencies for extended periods, thereby reducing cumulative losses in the switch elements while maintaining the ability to generate lower output voltages.
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 enables the generation of a wide range of output voltages with higher efficiency by optimizing switching frequency and reducing iron and copper losses, while maintaining transformer size and switch element performance.
Implementation Method 1
a resonant circuit (LLC resonant circuit) including the primary winding of the transformer, an inductor, and a capacitor
Data Source
AI summary
A power converter apparatus is provided with: a plurality of leg circuits, each including two switch circuits connected in series between input terminals; a transformer including a primary winding and a secondary winding, the primary winding having a first terminal and a second terminal; and at least one capacitor. The at least one capacitor is connected between the first terminal or the second terminal of the primary winding of the transformer, and a node between the two switch circuits in at least one leg circuit among the plurality of leg circuits. The first terminal of the primary winding of the transformer is connected to at least two nodes between the switch circuits in at least two first leg circuits among the plurality of leg circuits, via at least two first circuit portions having at least one of capacitances and inductances different from each other, respectively.