Resonant Power Converter Control for Harmonic Current Linearization
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Solution Overview
Problem
Existing power converter technologies require multiple stages, leading to cascaded efficiency losses and increased costs, and existing single-stage converters face challenges with wide input voltage ranges and load-dependent behavior, particularly in bidirectional power conversion.
Innovation Solution
A single-stage bidirectional power converter utilizing synchronous average harmonic and quadrature current control, with a voltage-controlled bridge and a current-controlled bridge, employing a bridge current sensor and compensators to linearize resonance and harmonic current transfer, allowing for efficient buck-boost regulation and series/parallel operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple stages are used for power conversion, then power factor correction and voltage regulation can be achieved, but cascaded efficiency losses and increased costs occur
Solution Approach 1:
The patent combines power factor correction and voltage regulation functions into a single-stage resonant power converter. The single-stage architecture integrates the rectification, power factor correction, and isolated DC-DC conversion that were previously separated into multiple stages, thereby eliminating cascaded efficiency losses while maintaining all required functions.
2Loss of energy
If a single-stage converter is used, then efficiency is improved, but handling wide input voltage ranges and load-dependent behavior becomes difficult
Solution Approach 1:
The patent employs dynamic control mechanisms including synchronous rectification with load-dependent switching timing and resonant frequency tracking that adapts to varying input voltage ranges and load conditions. The controller dynamically adjusts switching frequencies and duty cycles to maintain optimal efficiency across wide input voltage ranges and varying load conditions.
Solution Approach 2:
The patent changes operating parameters such as switching frequency and duty cycle dynamically to adapt to wide input voltage ranges and load conditions. The resonant power converter adjusts its operating point by varying the switching frequency relative to the resonant frequency, enabling efficient operation across different input voltages and load levels.
3Reliability
If bridge stages are used for bidirectional conversion, then voltage regulation is achieved, but additional components and complexity are required
Solution Approach 1:
The patent implements a universal single-stage resonant power converter that performs bidirectional power flow, power factor correction, and voltage regulation simultaneously. The same resonant tank and switching elements handle both rectification and DC-DC conversion functions in both forward and reverse modes, eliminating the need for separate bridge stages and reducing overall component count.
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 achieves efficient power transfer with reduced inductive filtering requirements, enabling buck-boost voltage regulation and material-efficient series and parallel connections, while minimizing harmonic content and switching losses.
Implementation Method 1
A resonant network couples a voltage controlled bridge to a current controlled bridge through a transformer to provide isolated power transfer
Implementation Method 2
A resonant network couples a voltage controlled bridge to a current controlled bridge through a transformer to provide isolated power transfer
Data Source
AI summary
A synchronous quadrature current compensator and synchronous average harmonic current compensator efficiently control harmonic current flow between isolated bridges of a clocked bidirectional resonant power converter. The synchronous average harmonic current compensator controls on a superposition of low frequency and switching current across nodes of a current controlled bridge to track commanded line current and harmonically linearize dynamic coupling admittance to a voltage controlled bridge. A difference amplifier attenuates the low frequency and reactive part of a bridge current signal to the quadrature current compensator. An error amplifier sums a synchronously modulated quadrature current signal, used to estimate transmitted harmonic current, to track a safely limited quadrature current command reference by generating a duty cycle. A line is inductively connected to the voltage controlled bridge or the current controlled bridge, with the other bridge driven with a duty cycle to command harmonic current flow between bridges.