Virtual Metering Accuracy via IED Hierarchy and Error Adjustment
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Solution Overview
Problem
Utility monitoring systems often overlook unmetered loads, which can account for a substantial portion of energy consumption, due to the lack of monitoring equipment at every point of utilization, leading to inaccurate virtual meter readings and unaccounted energy flows.
Innovation Solution
A method to automatically determine the hierarchy of intelligent electronic devices (IEDs) in a utility system, adjust measured quantities for measurement errors, and calculate the aggregate energy flow to identify unmonitored quantities, thereby improving the accuracy of virtual metering by determining if an unmonitored portion exists and its consumption or production status.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If monitoring equipment is installed at every point of utilization, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent creates virtual copies of metering functionality through software-based virtual meters that replicate the measurement capabilities of physical meters. These virtual meters are implemented as software entities that calculate and monitor energy consumption without requiring additional physical hardware at each utilization point, thereby maintaining measurement precision while reducing device complexity
Solution Approach 2:
The patent introduces an intermediary computational layer that acts as a mediator between physical meters and the monitoring system. This intermediary layer uses algorithms to allocate energy consumption from physical meter readings to multiple virtual meters representing different utilization points, enabling accurate tracking without direct physical measurement at each point
2Productivity
If virtual meters are used to monitor unmetered loads, then productivity is improved, but measurement precision deteriorates due to calculation errors
Solution Approach 1:
The patent implements feedback mechanisms where virtual meter readings are continuously compared against actual physical meter data and system state information. This feedback loop allows the system to detect and correct calculation errors, validate allocations, and refine measurement accuracy over time, thereby maintaining productivity while improving measurement precision
Solution Approach 2:
The patent performs preliminary actions by establishing accurate hierarchy relationships and measurement error characteristics before conducting virtual meter calculations. By pre-configuring the system with correct topological information and error parameters, the patent reduces calculation uncertainties and improves the precision of productivity-enhancing virtual metering
3Ease of operation
If data sampling is performed without synchronizing IEDs, then ease of operation is improved, but measurement precision deteriorates due to timing errors
Solution Approach 1:
The patent creates an equipotential timing reference by synchronizing all IEDs to a common time source or reference. This ensures that all devices operate on the same time baseline, eliminating timing drift and synchronization errors that would otherwise degrade measurement precision while maintaining operational simplicity through standardized time coordination
4Device complexity
If measurement errors are not adjusted for, then device complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
The patent applies parameter changes by adjusting measurement values based on known error characteristics of each IED. The system modifies raw measurement parameters using correction factors derived from manufacturer specifications or calibration data, thereby improving measurement precision through systematic parameter adjustment without significantly increasing device complexity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the accuracy of virtual metered load data by accounting for measurement errors and synchronizing data sampling across IEDs, allowing for more precise characterization of unmetered paths or loads in utility systems, applicable to various utility systems like electricity, water, gas, and steam.
Implementation Method 1
The law of conservation of energy states that energy may neither be created nor destroyed. Therefore, the sum of all the energies into and out of a system node must be zero. Using this principle, the energy flowing into a system bus must equal the energy flowing out of that system bus.
Data Source
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AI summary
Methods for improving the accuracy of characterizing unmonitored paths or virtual meters in a utility system. The hierarchical arrangement of IEDs in the utility system is determined. Measured quantities of a characteristic of the utility being monitored are received and error-adjusted using statistical or absolute methods. The statistical method accounts for the mean and standard deviation associated with error measurements of the subject IED, and the absolute method uses the absolute value of the error measurement, expressed as a percentage, to produce ranges of measured quantities within an error tolerance. The differences between the error-adjusted quantities are analyzed to determine whether an unmonitored path exists, and if so, whether the virtual meter is consuming or supplying the utility. The order in which IEDs are read is determined so that a parent and its children are read in sequence to increase synchronicity of the received data and the virtual meter evaluation.