State Estimation
The PowerFactory State Estimator provides an accurate real-time analysis of the full operating system based on the information provided by selectively monitored data, e.g. that of an installed SCADA system. The objective of the state estimator is to assess the generator and load injections in a way such that the resulting load flow solution matches as closely as possible the measured branch flows and busbar voltages. The features of PowerFactory’s State Estimation tool include:
- Flexible definition of external measurement devices in the network model supporting the following measurement types:
- Active and reactive power branch flows
- Branch current (magnitude)
- Busbar voltage (magnitude)
- Breaker status
- Transformer tap position
- User-definable selection of system states to be estimated/optimized:
- Loads: Active and reactive power demand, or alternatively the scaling factor
- Generators and static generators: Active and reactive power generation
- Asynchronous machines: Active power generation
- Static Var Systems: Reactive power injection
- Transformers: Tap positions
- High-precision estimation of full system state that minimizes deviations from measurements
- Fast-converging non-linear optimization algorithms
- Observability check based on a novel sensitivity analysis approach
- Detection of unobservable system states
- Grouping of unobservable states in equivalence classes
- Detection of redundant measurement locations
- Innovative patch strategies for unobservable areas; usage of automatically created pseudo-measurements
- Bad data detection in the loop
- Measurement plausibility checks as pre-processing, such as:
- Node sum checks for active and reactive power
- Check for consistent active power flow directions at each side of branch elements
- Check for unrealistic branch losses and unrealistic branch loadings
- Check for negative losses on passive branch elements
- Check for large branch flows on open-ended branch elements
- Statistical report and colouring modes to visualize measurement qualities
- Fully featured, large scale AC/DC system representation
The PowerFactory State Estimator is supporting a variety of communication options such as OPC (OLE for Process Control) or Shared Memory Interface for implementing data interchange with any kind of SCADA system.
