Parallel Power Converter with Shared Switching Leg
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Solution Overview
Problem
The existing power converters for hybrid and electric cars face challenges in reducing cost and size due to the need for high-voltage-compatible switching elements, which increase the number of elements required, leading to higher costs and larger sizes, especially when operating at small loads where conversion efficiency is low.
Innovation Solution
A power converter configuration with a common switching leg and two secondary switching legs connected in parallel, where the phase difference between switching control signals is controlled to zero when the output current is below a predetermined value, reducing the application voltage to one transformer and thereby minimizing losses and improving efficiency in light load states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If multiple switching power supply devices are connected in parallel to improve conversion efficiency, then copper loss is reduced and efficiency improves, but the number of high-voltage-compatible switching elements increases, leading to increased cost and size
Solution Approach 1:
The patent combines multiple switching power supply devices into a single integrated device with multiple switching legs sharing common components. Specifically, multiple primary windings are wound on a single transformer core, and multiple switching legs share common switching elements and magnetic components, thereby reducing the total number of discrete components while maintaining parallel operation capabilities for improved efficiency
Solution Approach 2:
The switching elements and magnetic components are designed to serve multiple functions simultaneously. The common transformer core handles multiple voltage conversion tasks, and the switching legs can operate independently or in combination, allowing the same hardware to function across different load conditions and efficiency requirements
2Power
If high-voltage-compatible switching elements are used to handle 400V motor drive voltage, then the power converter can supply power to motors, but the cost and occupied area increase
Solution Approach 1:
The patent merges multiple high-voltage switching functions into a single integrated transformer and switching leg structure. By winding multiple primary windings on one transformer core and sharing switching elements across multiple legs, the design reduces the number of high-voltage-compatible components needed while maintaining the ability to handle 400V for motor drive applications
3Loss of energy
If one switching power supply device is stopped when output current is small, then fixed loss decreases and efficiency improves, but the circuit configuration becomes more complex with additional control requirements
Solution Approach 1:
The patent implements dynamic control of the switching legs based on load conditions. The control circuit dynamically adjusts which switching legs are active based on the magnitude of the output current, stopping certain legs when current is small to reduce fixed losses, and activating them when current is large to maintain efficiency, thereby adapting the system behavior to operating conditions
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 number of high-voltage-compatible switching elements, decreases the size and cost of the power converter, and enhances conversion efficiency across all load states by minimizing copper and iron losses, especially in light load conditions.
Implementation Method 1
a first transformer (5) and a second transformer (6)
Data Source
AI summary
The present invention aims to provide a power converter, which includes a plurality of switching power supply devices connected in parallel, with a circuit configuration that enables reduction of cost and a size of the power converter. The present invention relates to a power converter including at least a first switching power supply device and a second switching power supply device connected in parallel. A part of high-voltage-compatible switching elements is commonly used between the first switching power supply device and the second switching power supply device, and a drive gate signal of one of the high-voltage-compatible switching elements of the first switching power supply device and the second switching power supply device and a phase difference of a drive gate signal of the commonly used switching power supply device are set to be equal when a load current is a first current value or lower.