Power Supply Input Voltage Evaluation via Delayed Signal Comparison

Solution Overview

Problem

Existing methods for evaluating the input voltage of switched-mode power supplies, particularly those with constant polarity and time-variable amplitude, are costly, require additional hardware, and are not effective in accurately detecting frequency and disturbances in three-phase supply voltages.

Innovation Solution

A system and method that involves sampling the input voltage at a high frequency, filtering it to introduce a time delay, and using a comparator to evaluate the signal, allowing for the determination of frequency and detection of disturbances without additional components or memory, and adapting to changing voltage conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If Fourier analysis is used to evaluate input voltage, then measurement precision is improved, but device complexity and cost increase due to additional hardware and memory requirements

Engineering Contradiction:

Improveinput voltage evaluation precisionVSAvoidhardware complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential feature needed for voltage evaluation - the zero-crossing points of the AC component - rather than performing complete Fourier analysis. By focusing solely on detecting when the voltage crosses zero and measuring the time interval between consecutive zero-crossings, the system achieves sufficient measurement precision without requiring complex computational algorithms or additional hardware resources.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces expensive and complex Fourier analysis with a simple timing measurement approach using basic comparators and counters. The evaluation is performed using readily available electronic components - a comparator to detect zero-crossings, a counter to measure time intervals, and a microcontroller to process the data - eliminating the need for specialized hardware or large memory resources.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Measurement precision

If Fourier analysis is used to evaluate input voltage, then measurement precision is improved, but manufacturing cost increases due to additional components and memory

Engineering Contradiction:

Improveinput voltage evaluation precisionVSAvoidmanufacturing cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent extracts only the essential feature needed for voltage evaluation - the zero-crossing points of the AC component - rather than performing complete Fourier analysis. By focusing solely on detecting when the voltage crosses zero and measuring the time interval between consecutive zero-crossings, the system achieves sufficient measurement precision without requiring complex computational algorithms or additional hardware resources.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces expensive and complex Fourier analysis with a simple timing measurement approach using basic comparators and counters. The evaluation is performed using readily available electronic components - a comparator to detect zero-crossings, a counter to measure time intervals, and a microcontroller to process the data - eliminating the need for specialized hardware or large memory resources.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Reliability

If continuous monitoring of input voltage is implemented, then reliability is improved, but device complexity increases due to additional monitoring components

Engineering Contradiction:

Improvesupply voltage monitoring reliabilityVSAvoidmonitoring system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent makes the existing control unit perform the monitoring function as part of its normal operation. The microcontroller that already controls the power supply continues to measure the time interval between zero-crossings and evaluate voltage conditions, eliminating the need for separate dedicated monitoring hardware. The control unit serves both its primary function and the monitoring function simultaneously.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent makes the existing control unit perform the monitoring function as part of its normal operation. The microcontroller that already controls the power supply continues to measure the time interval between zero-crossings and evaluate voltage conditions, eliminating the need for separate dedicated monitoring hardware. The control unit serves both its primary function and the monitoring function simultaneously.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS11879915B2Method and system for evaluating an input voltage of a power supply

Publication Date: 2024.01.23 SIEMENS AG

AI summary

Method and system for evaluating an input voltage of a power supply or a switched-mode power supply, wherein the input voltage has a constant polarity, where a digitized input voltage is supplied as the input signal to a filter which is filtered such that an output signal from the filter lags the input signal of the filter at the input of the filter, where the input signal and the output signal of the filter are compared, where comparison results are evaluated during an evaluation period until, following a first change in state of a comparison result, a further change in state of the comparison result is identified, and where a respective evaluation period is then terminated and subsequently, a period duration and/or a frequency of an AC voltage component of the input voltage are determined using the present count value of a counter.