Resonant Power Converter Amplitude Stabilization
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Solution Overview
Problem
Conventional resonant power converters are prone to a run-away fault mode when the load is short-circuited or open-circuited, leading to uncontrolled voltage and current increases, which can damage components in the converter.
Innovation Solution
A capacitor charger system with a resonant power converter that includes a switch-based bridge network, internal transformer, and an amplitude stabilization circuit with one-way conducting circuitry to stabilize the resonant amplitude within predefined limits, preventing run-away conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If resonant power converters are used for converting electrical power, then switching losses are reduced and operational switching frequencies are increased, but stability issues occur and current in the resonant circuit increases without limitation
Solution Approach 1:
The patent implements a control circuit that continuously monitors the current in the resonant circuit and adjusts the switching duty cycle accordingly. When current approaches a predefined threshold, the control circuit reduces the duty cycle to prevent runaway current increase, thereby maintaining stability while preserving the low switching loss benefits of resonant operation.
Solution Approach 2:
The patent incorporates protective circuitry that preemptively limits current by introducing damping resistance or altering the resonant circuit configuration before runaway conditions can develop. This preliminary protective action prevents instability while allowing the system to operate at high switching frequencies with minimal losses during normal operation.
2Productivity
If resonant power converters operate at high switching frequencies, then power conversion efficiency is improved, but components may be damaged due to uncontrolled current increase
Solution Approach 1:
The control circuit monitors resonant circuit current in real-time and provides feedback to adjust switching parameters. When current approaches dangerous levels, the control circuit immediately modifies the duty cycle or frequency to limit current, preventing component damage while maintaining high switching frequencies during normal operation.
Solution Approach 2:
The patent includes protective components such as current-limiting resistors or surge suppressors that are pre-positioned in the circuit to absorb or limit excessive current before it can damage critical components. These protective elements are designed to activate only under fault conditions, allowing high-frequency operation without compromising component safety.
3Adaptability or versatility
If load capacitor is short-circuited or open-circuited, then system operation continues, but voltage increases cycle-by-cycle without limit causing component failure
Solution Approach 1:
The control circuit detects abnormal voltage buildup across the load capacitor and responds by adjusting the switching duty cycle or enabling alternative current paths. This feedback mechanism prevents voltage from increasing without limit during short-circuit or open-circuit conditions, protecting components while maintaining system operation.
Solution Approach 2:
The patent introduces protective circuitry that acts as an intermediary between the resonant circuit and the load capacitor. This intermediary circuitry provides alternative current paths or voltage clamping mechanisms that prevent dangerous voltage buildup when the load capacitor experiences abnormal conditions, thereby protecting upstream components.
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
Effectively controls the run-away fault mode, providing protection to components and ensuring secure and reliable operation of the capacitor charger system by limiting resonant amplitude and preventing component failure.
Implementation Method 1
a resonant circuit including a series-resonant branch comprising at least one capacitive component (114) and at least one inductive component
Implementation Method 2
the amplitude stabilization circuit includes one-way conducting circuitry connected between i) an unrestricted node defined by a junction anywhere in the circuit path from a capacitive component to an inductive component of the series-resonant branch
Implementation Method 3
an internal transformer, wherein the capacitive component(s) of the resonant circuit is connected in a series path with a primary winding of the internal transformer
Data Source
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AI summary
In general, the capacitor charger system (100) comprises a resonant power converter (110) for connection to a capacitor (200) via an output rectifier (120). The resonant power converter (110) comprises a switch-based bridge network (112), an internal transformer (118), a resonant circuit (114), and an amplitude stabilization circuit (116). The switch-based bridge network (112) comprises at least one pair of controlled switches. The resonant circuit (114) includes a series-resonant branch comprising at least one capacitive component and at least one inductive component, and the resonant circuit is connected in the circuit path to a midpoint between a pair of controlled switches of the switch-based bridge network. Furthermore, the amplitude stabilization circuit (116) is configured to provide stabilization of the resonant amplitude of the resonant circuit, and the amplitude stabilization circuit includes one-way conducting circuitry connected between i) an unrestricted node defined by a junction anywhere in the circuit path from a capacitive component to an inductive component of the series-resonant branch and ii) at least one connection point of the resonant power converter having a predefined voltage level at operation. The resonant power converter (110) is configured for connection to the output rectifier (120) via the secondary winding of the internal transformer (118).