Power Signal Frequency Sensing Using Quarter-Cycle Derivatives
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Solution Overview
Problem
Existing power delivery systems face inefficiencies in frequency measurement, as they often require a complete power system cycle to determine frequency, which can be time-consuming and inadequate for fluctuating systems.
Innovation Solution
A method using waveform derivatives to calculate frequency in less than a complete cycle, allowing for more efficient and rapid frequency determination, enabling improved speed and accuracy in subsequent control operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If traditional frequency measurement methods are used, then measurement completeness is ensured, but measurement time is excessive (requiring a complete cycle)
Solution Approach 1:
The patent applies preliminary action by pre-calculating the derivative of the waveform and storing it in a lookup table before frequency measurement is needed. This pre-computed derivative information is then rapidly compared against current waveform values to determine frequency, eliminating the need to wait for a complete cycle while maintaining measurement accuracy through the pre-prepared derivative data.
Solution Approach 2:
The patent replaces the traditional mechanical/time-based frequency measurement approach (waiting for complete waveform cycles) with a mathematical/computational approach using derivative calculations. By substituting the physical waiting process with mathematical operations on waveform derivatives, the system achieves rapid frequency determination without sacrificing precision.
2Speed
If frequency measurement is accelerated to less than a complete cycle, then response speed improves, but measurement reliability may deteriorate
Solution Approach 1:
The patent implements feedback by continuously monitoring the waveform and its derivative, and using this real-time information to adjust and refine frequency measurements. The system compares the derivative values with actual waveform changes and uses this feedback to confirm frequency determinations, ensuring reliability even when measurements are completed in less than a full cycle.
Solution Approach 2:
By pre-computing and storing waveform derivatives in advance, the system has reliable reference data ready for immediate comparison during rapid measurements. This preliminary preparation ensures that even accelerated measurements under a complete cycle can rely on pre-validated derivative information, maintaining measurement reliability while achieving faster response times.
Data Source
AI summary
Systems and methods may be used to measure a frequency of a power delivery system and/or of a supply signal transmitted to a load. A system may record an input waveform, determine a frequency of the input waveform at a present time based at least in part on the input waveform and a derivative of the input waveform, and control an operation of a power delivery system based at least in part on the determined frequency.