Bridgeless PFC Converter Using Switch Transistors
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Solution Overview
Problem
The high cost and efficiency loss in bridgeless Power Factor Correction (PFC) circuits due to the use of silicon carbide diodes, which result in increased energy loss and reduced power conversion efficiency.
Innovation Solution
Replacing silicon carbide diodes with switch transistor tubes in the bridge arms of the PFC converter, connected in series and parallel configurations, to reduce cost and improve efficiency by minimizing voltage drop and energy loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If silicon carbide diodes are used in bridgeless PFC circuits, then the circuit can achieve power factor correction function, but the cost increases and power conversion efficiency decreases due to high voltage drop
Solution Approach 1:
The patent changes the key parameter from using silicon carbide diodes to using switch transistor tubes (such as MOSFETs or IGBTs) in the bridge arms. This parameter change reduces the voltage drop across the switching devices, thereby reducing energy loss and improving power conversion efficiency while maintaining the power factor correction function through controlled switching operations.
Solution Approach 2:
The patent substitutes the passive diode-based rectification mechanism with an active switch transistor tube-based switching mechanism. This replacement allows for controlled current flow and reduced voltage drop, transforming the circuit from a passive to an active system that can maintain lower conduction losses while achieving the same power factor correction objective.
2Reliability
If silicon carbide diodes are used in bridgeless PFC circuits, then the circuit can achieve power factor correction function, but the overall cost increases
Solution Approach 1:
The patent replaces expensive silicon carbide diodes with relatively cheaper switch transistor tubes (MOSFETs or IGBTs). Although switch transistor tubes require control circuits, the overall component cost is reduced, making the PFC circuit more economically viable while maintaining the required power factor correction functionality through controlled switching.
Solution Approach 2:
The patent changes the device type parameter from silicon carbide diodes to switch transistor tubes, which has a direct impact on cost reduction. This parameter substitution allows the circuit to achieve the same functional objective with lower component costs, improving the ease of manufacture and overall economic feasibility.
3Loss of energy
If switch transistor tubes are used instead of silicon carbide diodes, then cost and energy loss are reduced, but control complexity increases
Solution Approach 1:
The patent employs feedback control mechanisms where the control circuit monitors the switching states and current flow through the transistor tubes, adjusting the switching timing and duration to optimize performance. This feedback approach manages the control complexity by automatically adapting the switching parameters to maintain efficient operation and reduce energy loss.
Solution Approach 2:
The patent utilizes periodic switching actions of the transistor tubes in a structured sequence, where each switch tube operates in alternating phases. This periodic control pattern simplifies the management of complexity by establishing a predictable, repeating cycle of operations that can be easily synchronized and controlled.
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 use of switch transistor tubes lowers the overall cost and enhances power conversion efficiency by reducing voltage drop and energy loss, while simplifying the control of interleaved BOOST conversion circuits.
Implementation Method 1
L01 is charged through a power supply passing S01 and D04; and when a current reaches a set value, S01 is turned off, a power supply of L01 is reversed, and L01 is connected to the power supply in series, so as to charge an energy-storage capacitor through D01 and D04
Implementation Method 2
charge an energy-storage capacitor through D01 and D04, and transfer energy to a subsequent converted power supply
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A power factor correction converter and a control method thereof are provided, so as to decrease the cost, and improve the power conversion efficiency. The power factor correction converter includes an interleaving control tube set, an alternating current power supply, a first inductor, a second inductor, a third inductor, a capacitor, a first bridge arm and a second bridge arm. The first bridge arm includes a first switch tube and a second switch tube connected in series; the second bridge arm includes a third switch tube and a fourth switch tube connected in series; the interleaving control tube set, the first bridge arm, the second bridge arm, and the capacitor are connected to each other in parallel; the alternating current power supply and the first inductor are connected in series, and the second inductor and the third inductor are connected in parallel, and then connected to the first inductor in series; the second inductor is connected to the first bridge arm, and the second inductor is connected to the second bridge arm; and the alternating current power supply and the first inductor are connected in series, and then connected to the interleaving control tube set. A control method is further provided. According to the power factor correction converter and the control method, the cost is effectively decreased, and the power conversion efficiency is improved.