Three-Phase Frequency Estimation via Concordia and Park Transformations
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Solution Overview
Problem
Current methods for estimating the frequency of electrical signals in electricity grids are complex and computationally expensive, leading to slow response times and large-scale power outages, which are exacerbated by the increasing complexity of managing electricity supply from diverse sources in smart grids.
Innovation Solution
A method involving transformations such as Concordia and Park transformations, combined with a phase-locked loop and adaptive band-pass filtering, to accurately estimate the frequency of three-phase electrical signals, allowing for rapid and precise detection of frequency fluctuations and rate of change, enabling faster disconnection of loads to prevent blackouts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If classical methods are used to estimate fundamental frequency and rate of change of frequency, then frequency analysis can be performed, but the methods are complex and computationally expensive leading to slow response times
Solution Approach 1:
The patent segments the frequency estimation problem into distinct processing stages: signal conditioning, quadrature component generation, bandpass filtering, and frequency calculation. This segmentation allows each stage to be optimized independently, reducing overall computational complexity while maintaining accuracy.
Solution Approach 2:
The patent changes the parameter representation by transforming the original signal into quadrature components (I and Q) and then filtering these components through adaptive bandpass filters. This parameter transformation simplifies the frequency estimation calculation and reduces computational burden compared to classical methods.
2Speed
If protection relays operate quickly to detect frequency drift, then frequency monitoring is fast, but large areas of the network are cut off resulting in blackouts
Solution Approach 1:
The patent implements preliminary action by continuously monitoring frequency and its rate of change with high precision before abnormal conditions develop. The accurate real-time estimation allows the system to take preventive measures by isolating only affected areas rather than large portions of the network, thus maintaining power supply stability while ensuring fast response.
Solution Approach 2:
The patent employs feedback mechanisms where the estimated frequency and rate of change are continuously fed back to the control system. This feedback enables dynamic adjustment of protection settings and selective isolation of problematic areas, preventing widespread blackouts while maintaining fast response to frequency deviations.
3Extent of automation
If smart meters with disconnecting switches are deployed for network control, then remote control capability is improved, but processing resources on smart meters are limited requiring faster frequency estimation
Solution Approach 1:
The patent extracts only the essential frequency estimation functionality needed for smart meter operation, implementing a streamlined algorithm that uses minimal processing resources. By focusing on core functions (signal conditioning, quadrature transformation, bandpass filtering, and frequency calculation) and removing unnecessary complexity, the system achieves fast frequency estimation suitable for resource-constrained smart meter environments while maintaining remote control capability.
Data Source
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AI summary
The method comprises converting a first signal having three components into a second signal having two components in accordance with a first transformation (101), wherein each component of the first signal corresponds to a phase component of a three-phase electrical signal and the two components of the second signal are representative of characteristics of the three-phase electrical signal. The method further comprises filtering (102) the second signal in accordance with a previous frequency estimation. Then the method comprises converting the filtered second signal into a third signal having a single component in accordance with a second transformation (103), wherein the single component of the third signal is representative of characteristics of the three-phase electrical signal. Finally, the method comprises estimating a frequency of the third signal, wherein the estimated frequency of the third signal is indicative of a frequency of the three-phase electrical signal.