Isolated DC Supply Circuit Using Resonant Capacitive Transfer
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Solution Overview
Problem
Existing DC voltage supply devices for power electronics lack effective galvanic isolation, leading to potential interference and inefficiencies in signal and energy transmission.
Innovation Solution
A DC voltage supply device utilizing a combination of transfer capacitors and a transformer with a control device that creates resonant alternating voltages, achieving galvanic isolation and resonance enhancement to increase the secondary AC voltage, allowing for a compact and efficient design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If galvanic isolation is achieved using conventional transformers or capacitive coupling, then electrical isolation is provided, but the transformer requires high dielectric strength and results in larger device size and higher losses
Solution Approach 1:
The patent applies resonant oscillation at the secondary coil to generate high voltage peaks that enhance the AC voltage for charge transfer. By tuning the secondary circuit to resonate at a specific frequency, the system achieves voltage amplification without requiring larger transformer insulation, thus reducing transformer size while maintaining galvanic isolation reliability
Solution Approach 2:
The patent changes the operating parameters by introducing resonant frequency tuning in the secondary circuit. By adjusting the capacitance and inductance values to achieve resonance, the system transforms the voltage characteristics to produce higher peaks during specific phases, enabling efficient charge transfer through smaller transfer capacitors and reducing overall device volume
2Reliability
If conventional capacitive coupling is used for galvanic isolation, then signal transmission is achieved, but energy transmission efficiency is reduced due to lack of resonance enhancement
Solution Approach 1:
The patent introduces resonant oscillation in the secondary circuit to amplify voltage peaks during charge transfer phases. This resonant enhancement increases the energy transfer efficiency by maximizing the voltage difference across transfer capacitors at critical moments, thereby reducing energy losses while maintaining galvanic isolation
Solution Approach 2:
The system utilizes periodic switching of the semiconductor switch combined with resonant oscillation to create optimized periodic charge transfer cycles. The periodic action synchronizes with the resonant frequency, ensuring that charge transfer occurs at optimal voltage peaks, thus improving energy transmission efficiency while preserving galvanic isolation
3Reliability
If high dielectric strength transformers are used for galvanic isolation, then reliable electrical separation is achieved, but device complexity and size increase
Solution Approach 1:
By utilizing resonant oscillation to generate high voltage peaks dynamically, the system achieves effective galvanic isolation without requiring transformers designed for continuously high dielectric strength. The resonant approach transforms the isolation requirement from a static design constraint to a dynamic operational characteristic, simplifying transformer design while maintaining reliability
Solution Approach 2:
The patent changes the voltage profile characteristics through resonant tuning, creating time-varying voltage conditions that reduce peak stress on transformer insulation. This parameter transformation allows using transformers with lower dielectric strength ratings, thereby reducing device complexity and size while maintaining reliable galvanic isolation during operation
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 enhanced galvanic isolation with reduced transformer dielectric strength requirements, enabling a more compact and efficient design with lower losses and electromagnetic interference.
Implementation Method 1
a transformer (9) with a primary coil (10) and a secondary coil (11), wherein the primary coil (10) electrically connects the first voltage input (2) to the first switching contact (5)
Implementation Method 2
a magnetic coupling factor of the transformer (9), a capacitance of the first transfer capacitor (13), a capacitance of the second transfer capacitor (16) and an inductance of the secondary coil (11) are selected such that the secondary alternating voltage (WSS) has a resonance peak
Implementation Method 3
a first transfer capacitor (13) with a first contact (14) and a second contact (15) and a second transfer capacitor (16) with a first contact (17) and a second contact (18)
Data Source
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AI summary
The invention relates to a DC power supply device for converting an energy-supplying DC voltage into a supply DC voltage that is galvanically isolated from the energy-supplying DC voltage. The invention further relates to a power semiconductor circuit comprising a power semiconductor and a driver circuit for controlling the power semiconductor, and requiring a potential-free supply DC voltage for operation. The invention also relates to a power electronic circuit with such a power semiconductor circuit and with such a DC power supply device, wherein the DC power supply device supplies the power semiconductor circuit with the required potential-free supply DC voltage.