State estimation algorithm for monitoring distribution grid
Challenge and objective
The changes in future power grids are characterized by complexity, uncertainty and speed of changes, turning power systems into dynamical systems with dynamical characteristics.
Difficult with state estimation in smart grids because:
Expensive phasor measurement units (PMUs)
Lack of measurements in the system due to the consumers’ privacy consideration, dangerous accessibility, degradation of electrical equipment.
Unknown dynamical characteristics for some system components, especially for distributed generation
Work performed
Generated an accurate, robust and comprehensible estimate of operational state of the entire monitored power system (i.e. component’s dynamics, voltages, power angles, currents, power flows).
Significant results
A novel modelling approach for power systems with some unknown parts, considering the whole unknown parts of a power system as system-wide unknown inputs flow into the known part.
Developed a simultaneous input and state estimation method (SISE) to estimate the states of a partially known system with system-wide unknown inputs.
Impact for distribution system innovation
Prevent system-wide failures or blackouts, tune power system stabilizers, improve reliability of system models utilized for dynamic security assessment (DSA) and to design state estimator-based fault detectors.
