Three-Phase Voltage Reference Control for Fast Grid Synchronization

Solution Overview

Problem

Conventional uninterruptible power sources (UPS) and other power source devices struggle to respond at high speeds to steep fluctuations in three-phase voltage due to limitations in synchronization processing, primarily relying on zero-crossing detection which restricts control speed.

Innovation Solution

A reference three-phase voltage signal generation device utilizing an internal three-phase voltage signal generator, Clarke transformations, error generation, and inverse Clarke transformations to synchronize with external three-phase power wiring, enabling faster response to voltage fluctuations through closed-loop feedback control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If zero-crossing detection is used for phase synchronization, then the control logic is simple, but the response speed to voltage fluctuations is slow

Engineering Contradiction:

Improveresponse speed to voltage fluctuationVSAvoidcontrol logic complexity

Core Design Contradiction:

SpeedVSDevice complexity

Solution Approach 1:

The patent changes the detection parameter from zero-crossing points to peak points of the voltage waveform. By detecting the peak point of the external AC voltage and comparing it with the internal sine wave peak points, the system achieves faster response to voltage fluctuations while maintaining manageable control complexity through standardized peak detection algorithms.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces the conventional zero-crossing detection mechanism with a peak-point detection and comparison mechanism. This substitution enables continuous monitoring of voltage fluctuations throughout each cycle rather than only at zero-crossing moments, significantly improving response speed while the control logic remains structured and manageable.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If zero-crossing detection is used, then the detection method is simple, but the synchronization processing speed is limited

Engineering Contradiction:

Improvephase difference detection precisionVSAvoidsynchronization processing speed

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The patent changes the detection parameter from zero-crossing points to peak points of the voltage waveform. By detecting the peak point of the external AC voltage and comparing it with the internal sine wave peak points, the system achieves faster response to voltage fluctuations while maintaining manageable control complexity through standardized peak detection algorithms.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent implements continuous comparison between external and internal peak points throughout each voltage cycle, rather than relying on discrete zero-crossing events. This continuous monitoring approach maintains high measurement precision for phase difference detection while significantly increasing synchronization processing speed by capturing voltage fluctuation information at every peak point.

Inventive Principle:

Principle #20Continuity of useful action

3Reliability

If conventional PLL circuit with zero-crossing detection is used, then the circuit structure is simple, but the response to steep voltage fluctuation is slow

Engineering Contradiction:

Improvesynchronization reliabilityVSAvoidresponse speed to voltage fluctuation

Core Design Contradiction:

ReliabilityVSSpeed

Solution Approach 1:

The patent changes the detection parameter from zero-crossing points to peak points of the voltage waveform. By detecting the peak point of the external AC voltage and comparing it with the internal sine wave peak points, the system achieves faster response to voltage fluctuations while maintaining manageable control complexity through standardized peak detection algorithms.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent implements a feedback mechanism where the phase difference detected between external and internal peak points is continuously used to adjust the internal sine wave generation. This closed-loop feedback ensures high synchronization reliability while the peak-point detection method enables fast response to voltage fluctuations, resolving the contradiction between reliability and speed.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS20250244373A1Reference three-phase voltage signal generation device and reference three-phase voltage signal-using apparatus

Publication Date: 2025.07.31 SANSHA ELECTRIC MFG

AI summary

A reference three-phase voltage signal generation device includes: an internal three-phase voltage signal generator; a reference three-phase voltage signal generation unit that adds a three-phase voltage manipulated variable to an internal three-phase voltage signal to generate a reference three-phase voltage signal; a first Clarke transformation unit that transforms the reference three-phase voltage signal into a reference two-phase voltage signal; an external voltage signal sensor unit; a second Clarke transformation unit that transforms an external three-phase voltage signal into an external two-phase voltage signal; an error generation unit that generates a two-phase voltage error signal based on the reference two-phase voltage signal and the external two-phase voltage signal; a compensation unit that generates a two-phase voltage manipulated variable based on the two-phase voltage error signal, and an inverse Clarke transformation unit that transforms the two-phase voltage manipulated variable into the three-phase voltage manipulated variable.