State Estimation System Phase Judgment Power Grid
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Solution Overview
Problem
Existing state estimation systems for electrical power systems face performance deterioration during abnormalities due to incorrect phase information usage, especially when relying on measurements from Phasor Measurement Units (PMUs) or instantaneous value measurement units.
Innovation Solution
A state estimation system that includes a storage section for instantaneous value information, a judging section to determine if effective phase information can be obtained, and an instantaneous value processing section to calculate phase information or effective values based on this judgment, allowing for accurate state estimation even during abnormalities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If phase information is calculated from instantaneous value information during abnormalities, then state estimation can continue, but incorrect phase information is used causing performance deterioration
Solution Approach 1:
The judging section performs preliminary assessment of instantaneous value information quality before phase calculation is executed. By evaluating whether the information is suitable for phase calculation in advance, the system prevents incorrect phase information from being generated during abnormalities, thus maintaining state estimation reliability without compromising precision.
Solution Approach 2:
The judging section acts as an intermediary between instantaneous value information and phase calculation. It mediates by determining whether the input information is suitable for phase calculation, thereby controlling the flow of information and preventing incorrect data from entering the phase calculation process.
2Measurement precision
If measurement information is increased to enhance state estimation performance, then precision improves, but system complexity and cost increase
Solution Approach 1:
The system changes the processing parameters of existing instantaneous value information based on its quality assessment. Instead of always calculating phase or always using effective values, the system dynamically selects the appropriate parameter representation based on the judging section's evaluation, thereby enhancing precision without adding measurement devices.
Solution Approach 2:
The existing instantaneous value measurement units serve multiple functions: they provide both instantaneous values for direct use and serve as the basis for phase calculation when conditions permit. This self-service approach eliminates the need for separate PMU installations, maintaining precision while reducing system complexity.
3Loss of information
If phase information is always calculated from instantaneous values, then more complete information is obtained, but calculation time and processing load increase
Solution Approach 1:
Instead of always performing phase calculation (excessive action), the system performs phase calculation only when the judging section determines the instantaneous value information is suitable (partial action). This selective approach maintains information completeness where needed while reducing unnecessary calculation time and processing load.
Solution Approach 2:
The system dynamically adjusts its information processing strategy based on real-time conditions. The judging section continuously evaluates instantaneous value information quality, and the phase calculation is dynamically enabled or disabled accordingly, optimizing the balance between information completeness and processing efficiency.
Data Source
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AI summary
To enhance the performance of estimation of the state of an electrical power system. A state estimation system 1 that estimates a state of an electrical power system includes: a storage section that stores instantaneous value information D4 which is information of instantaneous values received from the electrical power system, and remote telemetry information D2, and phasor measurement information D3 which are measurement information received from the electrical power system; an instantaneous value processing section 3 that judges, on a basis of the instantaneous value information D4, whether or not effective phase information can be obtained from the instantaneous value information D4, and calculates phase information, and an effective value from the instantaneous value information in a case that it is judged that effective phase information can be obtained from the instantaneous value information, and calculates an effective value without calculating phase information from the instantaneous value information in a case that it is judged that effective phase information cannot be obtained from the instantaneous value information; and a state estimating section 4 that estimates the state of the electrical power system on a basis of: the calculated phase information, and the effective value, or the effective value calculated without calculating the phase information; the remote telemetry information, and the phasor measurement information; and a topology of the electrical power system.