Wide Area Control Reliability via Estimated Measurement Replacement
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Solution Overview
Problem
Wide area power oscillation damping in electric power transmission systems is hindered by measurement delays and deviations, which can lead to instability and potential blackouts, as existing solutions do not adequately address the reliability of control systems in handling delayed or faulty measurements.
Innovation Solution
A method and system that uses a model to estimate measurement values and tune the system model when no deviation conditions are met, allowing continued wide area power oscillation damping even with delayed measurements, by replacing delayed values with estimated ones and maintaining model tuning only when measurements are received in time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wide area power oscillation damping is implemented using measurements from various areas, then system performance is improved globally, but measurement delays occur due to long transmission distances
Solution Approach 1:
The system performs preliminary actions by continuously tuning the model parameters using received measurements before they are needed for control decisions. When measurements are delayed or missing, the already-tuned model can be used immediately, eliminating the waiting time that would otherwise be required for model tuning.
Solution Approach 2:
The invention creates a virtual copy of the power system through a mathematical model that replicates system behavior. This model copy can provide estimated measurements and system state information even when actual measurements are delayed or unavailable, allowing the control system to operate without waiting for real measurement data.
2Measurement precision
If all collected measurements are aligned in time before forwarding, then measurement accuracy is improved, but all measurements are delayed if one measurement is delayed
Solution Approach 1:
The system performs preliminary model tuning using available measurements before the complete aligned measurement set is ready. This allows the control system to begin operating with partially available data rather than waiting for all measurements to arrive and be aligned.
Solution Approach 2:
The invention accepts partial measurement sets for model tuning rather than requiring complete aligned measurements. By performing model tuning with available measurements and using estimated values for missing data, the system achieves sufficient accuracy without the excessive delay of waiting for complete data sets.
3Stability of the object's composition
If a Phasor Data Concentrator waits for all time-aligned measurements before forwarding, then data consistency is improved, but effective power oscillation damping stops when measurements are delayed
Solution Approach 1:
The system uses a mathematical model as a virtual copy of the power system to generate estimated measurements when actual measurements are delayed or missing. This model copy maintains data consistency through its internal state representations while providing continuous data for control, preventing damping effectiveness from stopping.
Solution Approach 2:
The mathematical model acts as an intermediary between the delayed actual measurements and the control system. It receives partial or delayed measurements, processes them through the model dynamics, and provides consistent estimated measurements to the controller, bridging the gap between inconsistent input data and control requirements.
Data Source
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AI summary
The invention is related to a method, arrangement and computer program product for enhancing the reliability of wide area control in a power transmission system where the wide area control is performed in the power transmission system based on measurements of system data. The arrangement comprises an estimating unit (40) configured to generate estimated measurement values (y1', y2', yn') based on at least one control signal (CS being sent into the system and a model (G) of the system, where the estimated measurement values correspond to a set of actual measurement values (y1, y2,..., yn) that are provided by a number of measurement providing devices in the system. The arrangement also comprises a control unit (38) configured to replace, if one or more deviation condition associated with at least one actual measurement value is fulfilled, at least the actual measurement values (y1) of the set being associated with the one or more deviation condition with corresponding estimated measurement values (y1').