Series Rectifier Circuit Reduces Switching Losses
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Solution Overview
Problem
Conventional rectifiers, such as those using diodes or power MOSFETs, experience significant losses due to forward biasing and reverse recovery effects, particularly in high-current power conversion applications, leading to inefficiencies and switching delays.
Innovation Solution
A circuit arrangement featuring a series connection of multiple semiconductor devices, including a first semiconductor device and multiple second semiconductor devices, where the second devices are connected in series and controlled to minimize losses by switching based on operation parameters like current and voltage, effectively reducing switching losses and improving voltage blocking capability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a diode is used as a rectifier, then the rectifier blocks reverse current, but significant losses occur due to forward bias and reverse recovery effects
Solution Approach 1:
The patent divides the rectifier function into multiple semiconductor devices connected in series, where each device handles a portion of the voltage blocking. This segmentation allows the use of devices with lower individual voltage ratings but collectively achieves the required voltage blocking capability while reducing overall losses compared to a single diode.
Solution Approach 2:
The patent changes the operating parameters by switching semiconductor devices on and off based on detected operation parameters (current, voltage). This dynamic parameter adjustment allows the rectifier to operate more efficiently by minimizing the time devices spend in high-loss states compared to a conventional diode that continuously conducts or blocks.
2Loss of energy
If a power MOSFET is used in a rectifier, then switching losses are reduced compared to diodes, but significant output capacitance causes switching delays and additional losses
Solution Approach 1:
The patent detects operation parameters (current, voltage) in advance to determine the optimal switching timing for MOSFETs. By predicting when switching should occur based on detected parameters, the system minimizes the impact of output capacitance charging/discharging delays and reduces overall switching losses.
Solution Approach 2:
The patent implements a feedback mechanism where operation parameters are continuously detected and used to control the switching of semiconductor devices. This closed-loop control optimizes switching timing to account for MOSFET output capacitance effects, reducing both energy losses and time delays.
3Reliability
If multiple semiconductor devices are connected in series, then voltage blocking capability is enhanced, but device complexity increases
Solution Approach 1:
The patent makes each semiconductor device in the series connection serve multiple functions: voltage blocking, current conduction, and participation in loss reduction through coordinated switching. This multi-functionality justifies the increased device count by maximizing the utility of each component in the series arrangement.
Data Source
AI summary
A circuit arrangement includes a rectifier circuit having a first and a second load terminal, a first semiconductor device having a load path and a control terminal and a plurality of n, with n>1, second semiconductor devices, each having a load path between a first load terminal and a second load terminal and a control terminal. The second semiconductor devices have their load paths connected in series and connected in series to the load path of the first semiconductor device. The series circuit with the first semiconductor device and the second semiconductor devices are connected between the load terminals of the rectifier circuit. Each of the second semiconductor devices has its control terminal connected to the load terminal of one of the other second semiconductor devices. One of the second semiconductor devices has its control terminal connected to one of the load terminals of the first semiconductor device.