Bidirectional DC Power Conversion Using Transformer Switching
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Solution Overview
Problem
Conventional electric power conversion devices using transformers cannot bidirectionally boost DC power due to a fixed direction of boosting determined by the transformer's transformation ratio, limiting their application in charge and discharge processes, such as battery charging and discharging.
Innovation Solution
An electric power conversion device with a transformer, a first conversion part, and a second conversion part, where the first conversion part includes a rectifying circuit and a switching section that switches between operation modes to bidirectionally convert and boost DC power using the transformer, allowing DC power to be boosted in both directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a transformer with a fixed transformation ratio is used for bidirectional DC power conversion, then the device structure is simple, but the boosting direction is fixed and cannot be switched between charge and discharge modes
Solution Approach 1:
The patent applies dynamics by making the connection state of the rectifying circuit changeable based on operation modes. The switching section dynamically connects or disconnects the rectifying circuit according to whether the system is in charge mode or discharge mode, enabling the transformer to function in both boosting directions without changing its physical structure. This resolves the contradiction by introducing temporal variability into an otherwise static system.
Solution Approach 2:
The patent achieves universality by designing a single transformer that can perform both boosting functions (step-up and step-down) depending on the connection state of the rectifying circuit. Instead of requiring separate transformers for different directions, the system uses one multi-functional transformer controlled by the switching mechanism, thereby enabling bidirectional operation while maintaining structural simplicity.
2Adaptability or versatility
If the rectifying circuit is always connected to the transformer, then the circuit structure is simple, but the voltage output cannot be adjusted for different operation modes
Solution Approach 1:
The switching section introduces dynamic control by connecting or disconnecting the rectifying circuit based on the operation mode. This allows the system to adapt the voltage output characteristics to match the requirements of either charge or discharge operations, resolving the contradiction between structural simplicity and voltage adjustability.
Solution Approach 2:
The patent changes the electrical connection parameters (connection state of the rectifying circuit) according to operation modes. By altering the circuit configuration through switching, the system adjusts its voltage transformation characteristics to suit different operational requirements, achieving parameter adaptability without complex structural modifications.
3Adaptability or versatility
If a bidirectional DC/DC converter with fixed transformation ratio is used, then the manufacturing cost is low, but the device cannot perform boosting in both charge and discharge directions
Solution Approach 1:
The patent achieves bidirectional boosting functionality using a single transformer designed for universal application. Instead of manufacturing separate transformers for different directions, the system uses one transformer with controllable connection states, thereby maintaining ease of manufacture while achieving enhanced functionality.
Solution Approach 2:
The patent introduces dynamic switching control that allows a single transformer to perform multiple functions. By controlling the connection state of the rectifying circuit through the switching section, the system enables bidirectional boosting without requiring multiple specialized components, thus maintaining cost-effectiveness while achieving versatility.
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
Enables bidirectional boosting of electric power, allowing for efficient charge and discharge operations by switching the connection state of the rectifying circuit based on operation modes, effectively overcoming the limitations of fixed transformation ratios in conventional devices.
Implementation Method 1
a transformer that is between the primary side circuit and the secondary side circuit
Implementation Method 2
The at least one first rectifying circuit is configured to output DC power by receiving power supply from the first winding
Data Source
AI summary
Electric power conversion device has first and second operation modes. First operation mode is of converting DC power from a first terminal into DC power having a desired voltage to be output to second terminal. Second operation mode is of converting DC power from the second terminal into DC power having a desired voltage to be output to first terminal. Switching section is configured to, in first operation mode, be turned on to cause short-circuiting between both ends of capacitor of rectifying circuit, and, in second operation mode, be turned off. First conversion part is configured to, in first operation mode, supply DC power-from first terminal, from first winding to second conversion part through a conversion circuit, and, in second operation mode, output to first terminal a voltage obtained by adding an output voltage of rectifying circuit to an output voltage of conversion circuit.