RSCC Switching Sequences for Full-Range Voltage Regulation

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Solution Overview

Problem

Resonant switched-capacitor converters (RSCCs) face challenges in achieving full-range voltage regulation due to transient current spikes, narrow voltage regulation range, and low efficiency, especially when voltage regulation is required.

Innovation Solution

The implementation of new switching control sequences that operate switches in a repeated asymmetric sequence of switching states, allowing for full-range voltage regulation by adjusting the voltage gain of RSCCs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If traditional switching control is used in RSCCs, then the converter operates with simple switching sequences, but voltage regulation range is narrow and transient current spikes occur

Engineering Contradiction:

Improveswitching control simplicityVSAvoidvoltage regulation range

Core Design Contradiction:

Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent applies dynamics by transitioning from fixed symmetric switching sequences to dynamic asymmetric switching sequences that adapt to different operating conditions. The switching control dynamically adjusts the duration and sequence of different switching states (T1, T2, T3, T4) based on the desired voltage gain, enabling full-range voltage regulation while maintaining ZCS operation.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the switching sequence parameters from symmetric to asymmetric patterns. By varying the duty cycles and timing of different switching states (changing the parameters of T1, T2, T3, T4 intervals), the voltage gain can be adjusted across the full range while preventing transient current spikes through proper parameter selection.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If voltage regulation is implemented in conventional SCCs, then voltage control is achieved, but transient current spikes and low efficiency occur

Engineering Contradiction:

Improvevoltage regulation capabilityVSAvoidconverter efficiency

Core Design Contradiction:

Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent uses periodic asymmetric switching sequences that repeat every switching cycle but with asymmetric duration distribution. This periodic action with controlled asymmetry enables continuous voltage regulation while maintaining resonant operation that prevents current spikes and reduces energy loss through soft switching.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent implements voltage regulation through feedback by monitoring the output voltage and adjusting the asymmetric switching sequence parameters accordingly. The control system modifies the duty cycles of different switching states based on the voltage error signal, achieving precise voltage regulation while maintaining efficiency through ZCS operation.

Inventive Principle:

Principle #23Feedback

3Reliability

If symmetric switching sequences are used in RSCCs, then zero current switching is achieved, but full-range voltage regulation cannot be implemented

Engineering Contradiction:

Improvezero current switching operationVSAvoidvoltage gain adjustment range

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent directly applies asymmetry by using asymmetric switching sequences where the duration of different switching states (T1, T2, T3, T4) are not equal. This asymmetric pattern allows the voltage gain to be adjusted across the full range while maintaining ZCS operation, as the asymmetry is carefully controlled to preserve the resonant current zero-crossing conditions.

Inventive Principle:

Principle #4Asymmetry

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 solution enables RSCCs to achieve full-range voltage regulation for all load levels, improving efficiency and reducing transient current spikes, while also enabling zero current switching (ZCS) operation.

Implementation Method 1

By adding one or multiple small inductors to the SCCs, resonant operation is enabled. The resulting converters, known as 'resonant switched-capacitor converters' (RSCCs) overcome capacitor charge sharing losses and transient current spikes and provide zero current switching (ZCS) operation of switches and diodes.

Methodology Applied

Scientific EffectResonance: Resonance

Data Source

PatentUS12237764B2Switching methods for regulating resonant switched-capacitor converters

Publication Date: 2025.02.25 RGT UNIV OF CALIFORNIA

AI summary

Various examples are provided related to switching methods for regulating resonant switched-capacitor converters (RSCCs). In one example, a method includes operating switches of the RSCC in a repeated asymmetric sequence of switching states per switching cycle. The repeated asymmetric sequence can include at least three switching states selected from five defined switching states including an idle state. For example, repeated asymmetric sequence can consist of four switching states selected from the five defined switching states. In another example, a method includes operating switches of the RSCC in a repeated sequence of switching states per switching cycle. The repeated sequence can include six switching states selected from five defined switching states with at least one of the five defined switching states occurs twice in the six switching states. For example, the repeated sequence can consist of each of the five defined switching states with the idle state occurring twice.