Aircraft Power Rectifier Circuit Using Cascaded Boost Cells
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Solution Overview
Problem
Existing power rectifier circuits face challenges with high weight and complexity due to high-value AC-side inductors, increased power losses, and reliability issues, particularly in aircraft applications where fault tolerance and efficient energy management are critical.
Innovation Solution
A fault-tolerant multi-level voltage rectifier circuit using single transistor and single diode per cell boost cells, with separate switching assemblies to reduce stress and thermal coupling, allowing operation under reduced voltage and frequency, thereby minimizing component calibration and power losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If standardized symmetrical switching cells with two transistor-diode assemblies are used, then the circuit is versatile and modular, but the device complexity increases due to high number of transistors and electronic controls
Solution Approach 1:
The circuit is divided into multiple independent boost cells, each handling a portion of the rectification task. This segmentation allows the system to maintain versatility through modular configuration while reducing the complexity of individual cell control, as each cell operates with simplified single transistor-diode switching rather than complex dual transistor-diode assemblies
Solution Approach 2:
The invention extracts and eliminates the redundant transistor-diode assembly from each switching cell, retaining only the essential single transistor and diode needed for boost operation. This extraction maintains the modular nature of the circuit while dramatically reducing the number of control elements required
2Adaptability or versatility
If standardized symmetrical switching cells with two transistor-diode assemblies are used, then the circuit is modular, but power losses increase due to high-frequency switching of multiple components
Solution Approach 1:
By segmenting the rectification function into multiple independent boost cells, each cell processes a smaller portion of the total power at lower switching losses. The cumulative effect across all cells achieves the required power conversion with reduced total power losses compared to fewer complex cells switching at high frequency
Solution Approach 2:
The invention uses simpler, lower-cost single transistor-diode assemblies that can operate at reduced switching frequencies, accepting shorter component lifetimes or higher stress as a trade-off for reduced power losses and simplified control, rather than using expensive high-performance components designed for high-frequency operation
3Power
If voltage splitting on two levels is used, then the rectifier can handle high power, but high-value AC current smoothing inductors are required resulting in significant bulk and weight
Solution Approach 1:
The invention transitions from traditional two-level voltage splitting to multi-level voltage architecture with multiple intermediate voltage stages. This dimensional expansion in voltage levels allows power handling capability to be maintained or increased while distributing the energy storage requirement across multiple smaller capacitors and inductors, significantly reducing the bulk and weight of individual magnetic components
Solution Approach 2:
The boost cells are nested in a cascaded configuration where each cell operates at a different voltage level, with output capacitors of one cell serving as input for the next. This nesting allows efficient power processing at each voltage stage with smaller, lighter inductors and capacitors compared to a single-stage high-power design
4Stress or pressure
If conventional switching cells with two transistors in series are used, then the circuit can operate at high voltage, but reliability decreases due to short-circuit risk and fault propagation
Solution Approach 1:
The high voltage handling is achieved through segmentation into multiple series-connected boost cells, each operating at a fraction of the total voltage. This segmentation isolates faults to individual cells, preventing catastrophic failure and improving reliability, as a failure in one cell does not necessarily compromise the entire system
Solution Approach 2:
The circuit incorporates inherent protection mechanisms where diodes and capacitors are positioned to prevent short-circuit propagation before it can occur. The boost topology naturally limits current during faults, and the modular structure provides built-in isolation that cushions against failure propagation, eliminating the need for complex external protection circuits
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 provides a compact, efficient, and reliable power rectifier circuit with reduced component size and power losses, enhanced fault tolerance, and improved safety by isolating faults without additional redundancy, suitable for aircraft applications.
Implementation Method 1
a power rectifier circuit for rectifying an alternating current supplied by a power source into a direct current
Implementation Method 2
essentially based on power semiconductors whose pulse modulation makes it possible to adjust the flow of power taken from the AC network
Implementation Method 3
involving the use at the rectifier input, high-value AC current smoothing inductors as a function of the volt-seconds
Implementation Method 4
Each cell comprises a diode, a transistor-type switch and a capacitor
Data Source
Figure 1~2b
Figure 3a~3b
Figure 4~5
AI summary
The invention relates to a power rectifying circuit (30) for an electric current signal supplied by an alternating power source (12), which comprises: two separate switching assemblies (30a, 30b) adapted to be connected to a power terminal (31) of the source, wherein at least one switching assembly includes a plurality of boost cells (310a, 310b, 320a, 320b) in cascade, each boost cell including a diode (312a, 312b, 322a, 322b), a switch means (314a, 314b, 324a, 324b) and a capacitor (316a, 316b, 326a, 326b), the so-called terminal capacitors (326a, 326b) of the two terminal boost cells (320a, 320b) of the switching assemblies having one terminal in common. The circuit may particularly include two assemblies of boost cells. The invention can be used in electric systems onboard aircrafts.