Class-E Resonant Circuit Transformerless Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Two-stage power converters used for power factor correction and isolation result in increased design complexity, component counts, PCB size, and cost due to the need for transformers for galvanic isolation.
Innovation Solution
A cascade power system comprising a non-isolated buck converter cascaded with an isolated Class-E resonant circuit, where the Class-E resonant circuit operates at high frequency, providing capacitive isolation and impedance matching independent of the output load condition, thereby eliminating the need for transformers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a two-stage power converter with transformer is used for galvanic isolation and power factor correction, then power conversion efficiency and isolation are improved, but device complexity and component count increase
Solution Approach 1:
The patent extracts and eliminates the transformer component from the traditional two-stage power converter architecture. By using a single-stage resonant half-bridge converter with power factor correction capability, the design removes the need for separate isolation transformer while maintaining galvanic isolation through the resonant tank circuitry, thereby reducing design complexity and component count
Solution Approach 2:
The resonant half-bridge converter circuit is designed to perform multiple functions simultaneously: power factor correction, voltage transformation, and galvanic isolation. This multi-functional approach consolidates what would traditionally require separate stages and components into a single integrated circuit, reducing overall device complexity while maintaining isolation performance
2Reliability
If a two-stage power converter with transformer is used for galvanic isolation, then isolation performance is improved, but component count and cost increase
Solution Approach 1:
The transformer component is extracted and removed from the design. The galvanic isolation function is achieved through the resonant half-bridge circuit topology itself, which provides isolation without requiring a separate transformer component, thereby reducing component count
Solution Approach 2:
The patent merges the functions of power factor correction, voltage transformation, and galvanic isolation into a single resonant half-bridge converter stage. This consolidation eliminates the need for separate transformer component and reduces overall component count while maintaining isolation performance
3Power
If a two-stage power converter with transformer is used, then power conversion capability is improved, but PCB size and cost increase
Solution Approach 1:
The large transformer component is extracted and removed from the design. The resonant half-bridge converter achieves power conversion and isolation without requiring a bulky transformer, significantly reducing PCB area while maintaining power conversion capability
Solution Approach 2:
The patent employs resonant frequency operation and optimized component values to achieve efficient power conversion in a compact configuration. By operating at resonant frequencies and optimizing the L and C values in the resonant tank, the design achieves effective power conversion without requiring large physical components, thereby reducing PCB size
4Stability of the object's composition
If traditional power converter topology is used, then stability is improved, but energy efficiency decreases
Solution Approach 1:
The patent employs resonant oscillation at specific frequencies to achieve efficient energy transfer. The resonant half-bridge converter operates by periodically switching the resonant tank at its resonant frequency, which minimizes energy losses while maintaining stable output voltage through the natural resonance of the L-C circuit
Solution Approach 2:
The design optimizes component parameters (inductance L and capacitance C values) to achieve resonant operation at the desired frequency. By carefully selecting these parameters, the circuit achieves both stable output voltage regulation and high energy efficiency, overcoming the trade-off present in traditional topologies
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
This configuration reduces design complexity, component counts, and costs while maintaining efficient power conversion and regulation, with improved energy efficiency and reduced component size due to lower voltage ratings and high-frequency operation.
Implementation Method 1
the resonant tank has an impedance matched to enable resonance at an operating switching frequency of the second switching element
Data Source
AI summary
A cascade power system includes a non-isolated buck converter in cascade with an isolated Class-E resonant circuit, where the Class-E resonant circuit operates at high frequency, for example 4 Mhz. Further, the non-isolated buck converter is configured as a current source coupled to the Class-E resonant circuit which provides a buck converter output voltage as input to the Class-E resonant circuit. The Class-E resonant circuit includes capacitive isolation for the cascade power system output. The Class-E resonant circuit and the capacitive isolation are configured such that impedance matching for the resonant tank of the Class-E resonant circuit is independent of an output load condition.