Input Voltage Abnormality Detection Using Phase Locked Loop
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional power outage detection methods in uninterruptible power supply devices are unable to achieve extremely quick and reliable detection, often requiring significant time and risking erroneous detection due to the difficulty in distinguishing between power outages and normal voltage fluctuations.
Innovation Solution
A method and device utilizing a phase locked loop to generate a simulated voltage waveform synchronized with the input voltage, allowing for rapid comparison and determination of input voltage abnormalities, including power outages, by shifting from current conduction mode to storage battery discharge mode when the input voltage deviates from the simulated waveform.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional power outage detection methods are used, then the detection process is simple to implement, but the detection speed is slow and reliability is low due to inability to distinguish power outages from voltage fluctuations
Solution Approach 1:
The system pre-generates a simulated voltage waveform using a phase locked loop before actual power outage detection is needed. This simulated waveform serves as a reference template that is continuously updated, enabling rapid comparison when power outage detection is required without needing to build the reference waveform at that moment.
Solution Approach 2:
The invention creates a copy of the input voltage waveform through the phase locked loop to generate a simulated voltage waveform. This copied waveform can be rapidly compared against the actual input voltage to detect outages, avoiding the need for complex analysis of the original waveform while maintaining detection accuracy.
2Loss of time
If conventional detection methods are used, then the system complexity is low, but the detection time is excessive and erroneous detection of temporary voltage variations occurs
Solution Approach 1:
The phase locked loop continuously generates and updates the simulated voltage waveform in advance, so when power outage detection is needed, the comparison can be performed immediately without waiting for waveform generation. This preliminary preparation of the reference waveform dramatically reduces detection time.
Solution Approach 2:
The invention replaces complex mechanical or analog waveform generation and comparison mechanisms with electronic digital signal processing using a phase locked loop. This substitution enables extremely fast waveform generation and comparison operations that would be impractical with traditional mechanical systems.
3Speed
If the detection sensitivity is increased to detect power outages quickly, then the detection speed improves, but erroneous detection of temporary voltage variations increases
Solution Approach 1:
The phase locked loop uses feedback mechanisms to continuously monitor and adjust the simulated voltage waveform to match the characteristics of the input voltage. This feedback ensures that the reference waveform accurately reflects normal voltage variations, allowing the system to distinguish between expected fluctuations and actual power outages even when operating at high detection sensitivity.
Data Source
AI summary
This abnormality detection method for a single-phase AC input voltage is executed by a control unit having a function of a phase locked loop, and includes: sequentially generating a simulated voltage waveform with a phase synchronized with the input voltage, by using the phase locked loop; and within a period until a next update of the generated simulated voltage waveform, comparing the instantaneous value of the input voltage with the simulated voltage waveform, and when the instantaneous value of the input voltage changes from a state of being along the simulated voltage waveform to a state of not being along the simulated voltage waveform, determining that the input voltage is abnormal.