Power Supply Capacitor Segmentation for Surge Voltage Suppression
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Solution Overview
Problem
Existing power supply devices face challenges in suppressing peak surge voltage without increasing capacitor capacitance, leading to heat generation and reduced efficiency due to resonance between transformer leakage inductance and snubber capacitor capacitance.
Innovation Solution
A power supply device configuration that includes a second capacitor section generating harmonic waves to combine with the fundamental wave, reducing peak surge voltage without increasing the capacitance of the first capacitor section, and incorporating a filtering section to reduce alternating-current components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the capacitance of the snubber capacitor is increased to suppress the peak value of surge voltage, then the peak surge voltage is reduced, but the current flowing to the snubber capacitor increases and heat generation increases
Solution Approach 1:
The capacitor is divided into two separate capacitor sections with different capacitance values. The first capacitor section (C1) is connected in parallel with the rectifying element and has a smaller capacitance to limit current and heat generation. The second capacitor section (C2) is connected in series with a diode and has a larger capacitance to effectively suppress peak surge voltage. This segmentation allows each capacitor to perform its specific function optimally without the drawbacks of using a single large capacitor.
2Reliability
If the capacitance of the snubber capacitor is increased to suppress surge voltage, then the peak surge voltage is reduced, but power efficiency decreases
Solution Approach 1:
The capacitor is divided into two separate capacitor sections with different capacitance values. The first capacitor section (C1) is connected in parallel with the rectifying element and has a smaller capacitance to limit current and heat generation. The second capacitor section (C2) is connected in series with a diode and has a larger capacitance to effectively suppress peak surge voltage. This segmentation allows each capacitor to perform its specific function optimally without the drawbacks of using a single large capacitor.
3Device complexity
If a single capacitor is used to suppress surge voltage, then the circuit is simple, but the capacitance must be increased which causes heat generation and efficiency loss
Solution Approach 1:
The capacitor is divided into two separate capacitor sections with different capacitance values. The first capacitor section (C1) is connected in parallel with the rectifying element and has a smaller capacitance to limit current and heat generation. The second capacitor section (C2) is connected in series with a diode and has a larger capacitance to effectively suppress peak surge voltage. This segmentation allows each capacitor to perform its specific function optimally without the drawbacks of using a single large capacitor.
Solution Approach 2:
A diode is introduced as an intermediary element connected in series with the second capacitor section. This diode controls the current flow direction, allowing the second capacitor to suppress peak surge voltage while preventing it from causing excessive current and heat generation during normal operation. The diode acts as a mediator that enables the larger capacitor to function only when needed for surge suppression.
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 effectively suppresses peak surge voltage, maintains efficiency, and reduces heat generation in the capacitors by allowing the second capacitor section to operate separately from the first, with adjustable capacitance ratios to optimize resonance cancellation.
Implementation Method 1
The second capacitor section generates one or more harmonic waves that reduce a peak value of a fundamental wave of resonance generated based on a leakage inductance component of the transformer and a capacitance component of the at least one first capacitor section
Implementation Method 2
The transformer inputs an electric power via at least one pair of primary-side terminals, transforms the input electric power, and outputs the transformed electric power via at least one pair of secondary-side terminals
Implementation Method 3
The rectifying section includes at least one rectifying element configured to rectify the transformed electric power
Data Source
AI summary
A power supply device includes a substrate, a transformer, a rectifying section, a filtering section, at least one first capacitor section, and a second capacitor section. The substrate includes at least one semiconductor element. The transformer inputs an electric power via at least one pair of primary-side terminals, transforms the input electric power, and outputs the transformed electric power via at least one pair of secondary-side terminals. The rectifying section includes at least one rectifying element configured to rectify the transformed electric power. The filtering section reduces alternating-current components included in the rectified electric power. The first capacitor section is connected in parallel to the at least one rectifying element. The second capacitor section generates one or more harmonic waves that reduce a peak value of a fundamental wave of resonance generated based on a leakage inductance component of the transformer and a capacitance component of the first capacitor section.