Semi-Active Bridge Rectifier for Low-Loss Voltage Conversion
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Solution Overview
Problem
Existing voltage converting devices face inefficiencies due to high forward voltage drops in bridge diodes, leading to increased manufacturing costs and reduced power conversion efficiency, especially in active bridge rectifiers that require high-side drivers.
Innovation Solution
A semi-active bridge rectifier is implemented using an operational amplifier, resistors, and switches to minimize manufacturing costs and enhance efficiency by utilizing half-wave voltages for input voltage rectification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional bridge rectifier with bridge diodes is used, then the device structure is simple, but the forward voltage drop is high causing reduced power conversion efficiency
Solution Approach 1:
The patent changes the operating parameters of the rectifier by replacing the passive bridge diode structure with an active switching circuit using MOSFETs controlled by operational amplifiers. This transforms the rectification mechanism from passive diode conduction to active switch-controlled current direction, fundamentally changing the electrical parameters and eliminating the forward voltage drop issue.
Solution Approach 2:
The patent substitutes the mechanical/passive diode-based rectification system with an electronic active switching system. The operational amplifiers and MOSFETs create an electronically controlled rectification process that replaces the passive semiconductor diode mechanism, achieving superior efficiency through active control rather than passive component characteristics.
2Loss of energy
If an active bridge rectifier with MOSFETs is used, then power conversion efficiency is improved, but manufacturing cost increases due to high-side drivers
Solution Approach 1:
The patent extracts and eliminates the high-side driver component from the active bridge rectifier system. By reconfiguring the circuit so that the source of the top MOSFET is connected to ground rather than requiring a floating gate driver, the design removes the complex and costly high-side driver circuitry while maintaining the efficiency benefits of active switching.
Solution Approach 2:
The patent inverts the conventional active bridge rectifier topology by connecting the source of the top MOSFET to ground instead of the drain, and by using the operational amplifier output directly to control the gate without an intermediate high-side driver. This topological inversion simplifies the circuit structure and eliminates the need for complex driver circuits.
3Loss of energy
If an active bridge rectifier is used, then power conversion efficiency is enhanced, but device complexity increases due to additional control circuits
Solution Approach 1:
The operational amplifiers in the patent serve multiple functions simultaneously: they detect the input voltage polarity, control the switching of MOSFETs, and provide feedback for regulation. This multi-functionality reduces the need for separate control circuits, simplifying the overall device complexity while maintaining efficient active rectification.
Solution Approach 2:
The patent merges the control functions for multiple MOSFETs into a single operational amplifier circuit configuration. The operational amplifiers coordinate the switching of both half-bridge pairs through integrated control, combining what would traditionally require separate control circuits into a unified control architecture that reduces component count and complexity.
Data Source
AI summary
A voltage converting device may comprise: a bridge rectifier configured to rectify an input voltage and outputs a first AC voltage; a power factor corrector comprising circuitry configured to convert the first AC voltage into a first DC voltage based on power factor correction; a DC-DC converter configured to convert the first DC voltage into a second DC voltage; and a PFC controller comprising circuitry configured to control at least one of the bridge rectifier, the power factor corrector, and the DC-DC converter. The bridge rectifier may be configured to output the first AC voltage by rectifying the input voltage using at least one operational amplifier, at least one switch, at least one diode, and at least one resistor.