Three-Level AC Power Supply Circuit With Soft Switching Cell
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Solution Overview
Problem
Existing alternating current power supply circuits face high switching losses and inefficiencies due to hard switching, making it difficult to improve efficiency, especially when applied to alternating current power supplies.
Innovation Solution
The implementation of a soft switching circuit with a rectifier and inverter module, utilizing a soft switching cell and controlled switching components to reduce switching losses, and incorporating filter capacitors to minimize ripple currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If hard switching circuit topology is used, then circuit structure is simple, but switching loss is large and efficiency is difficult to improve
Solution Approach 1:
The circuit is divided into multiple switching components (first switching component and second switching component) arranged in series within the third branch. This segmentation allows independent control of each component to achieve soft switching conditions, reducing overall switching loss while maintaining manageable circuit complexity through modular design.
Solution Approach 2:
The patent implements dynamic switching control where the first and second switching components are controlled to turn on and off at different times based on real-time circuit conditions. This dynamic control enables zero-voltage or low-voltage switching, significantly reducing switching losses compared to fixed hard switching topologies.
2Loss of energy
If resonant soft switching technology is applied, then efficiency can be improved, but it is difficult to apply to alternating current power supply due to high circuit complexity and poor stability
Solution Approach 1:
The patent introduces an auxiliary inductor and auxiliary capacitor as intermediary elements that facilitate soft switching without requiring complex resonant circuits. These intermediary components create a controlled energy transfer path that enables soft switching while maintaining circuit stability and simplicity suitable for AC power supply applications.
Solution Approach 2:
The patent changes the switching parameters by controlling the first and second switching components to operate at different timing and with different duty cycles. This parameter variation enables the circuit to achieve soft switching conditions adaptively, improving efficiency while maintaining stability in AC power supply environments.
3Productivity
If three-level topology is used, then power conversion efficiency is improved, but switching loss remains high due to hard switching
Solution Approach 1:
The patent applies preliminary action by pre-charging or pre-discharging the auxiliary capacitor through the auxiliary inductor before the main switching event. This preliminary energy preparation enables the main switching components to transition under soft switching conditions, reducing switching loss while maintaining the power conversion efficiency benefits of the three-level topology.
Solution Approach 2:
The patent implements periodic action through oscillatory current flow in the auxiliary inductor and periodic charging/discharging of the auxiliary capacitor. This periodic energy exchange creates favorable conditions for soft switching at regular intervals, reducing switching losses while preserving the high power conversion efficiency characteristic of three-level topologies.
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
The solution reduces energy consumption and improves efficiency by enabling zero voltage switching of transistors, thereby minimizing energy loss and enhancing the performance of alternating current power supply circuits.
Implementation Method 1
a first end of the soft switching cell is connected to a common end of the first capacitor and the second capacitor
Implementation Method 2
a first end of the first inductor is connected to an input potential, a second end of the first inductor is connected to a common end of the first branch, the second branch, and the third branch
Data Source
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AI summary
Embodiments of this application provide an alternating current power supply circuit, a control method for an alternating current power supply circuit, and an alternating current power supply. The alternating current power supply circuit includes a rectifier module and an inverter module. The rectifier module includes a first inductor, a first branch, a second branch, a third branch, a first capacitor, and a second capacitor, the third branch includes a soft switching cell, the soft switching cell includes a first switching component and a second switching component that are reversely connected in series, and the first branch, the second branch, and the third branch form an I-type three-level topology or a T-type three-level topology. The inverter module includes a second inductor, a fourth branch, a fifth branch, a sixth branch, the first capacitor, and the second capacitor, the sixth branch includes the soft switching cell, and the fourth branch, the fifth branch, and the sixth branch form an I-type three-level topology or a T-type three-level topology. In the alternating current power supply provided in embodiments of this application, zero voltage switching of a switching component is implemented, and the switching component is turned off at zero voltage in a case of a low current, to reduce energy consumption of the switching component.