Distribution State Estimator
As distribution systems are becoming more interconnected and complex, their efficient planning and operation require an accurate and trustworthy power flow solution obtained from a detailed electrical model with its inherent share of imprecision.
The CYME Distribution State Estimator module features a refined algorithm which takes detailed network modeling to a newer level by being able to process various measurements in order to estimate the power flow and voltages of the system.
It has always been a challenging task for utilities to ensure electricity supply with the current infrastructure while keeping the costs low. As engineers contemplate options such as capacitor placement and Volt/VAR optimization to yield a more optimal outcome from the system’s assets, other solutions exist as a first step to reducing electricity cost while minimizing the impact on capital use. Reconfiguring the network through switching is one such solution.
The Network Configuration Optimization module is an additional module to the CYME Power Engineering Analysis Software designed to provide engineers with switching plans to obtain optimal network topologies.
The reconfiguration of networks often brings benefits such as reduction of power losses and voltage violations counts. The module offers the following different objectives:
- Perform load transfer studies to determine how loads can be transferred from a heavily loaded substation or feeder to another through tie-points
- Minimize voltage exception to reduce the number of voltage violations
- Minimize overload exceptions to reduce the number of overloaded equipments
- Limit the exposure of certain feeders by transferring part of their circuit to other feeders to improve reliability
- Improve system kW losses to reduce operating cost
State estimation for secondary grid networks
The Distribution State Estimator analysis is based on a rigorous mathematical formulation that can handle large interconnected systems. This robust algorithm makes the state estimation of heavily meshed systems such as secondary networks possible. Load values can be estimated while low-voltage cable currents can be calculated for increased grid awareness.
Unlike traditional algorithms such as power flow and load allocation, the Distribution State Estimator takes into account by-phase voltage measurements, along with other traditional measurements (Amps, kW, kVAR). A voltage meter can be installed at any node of the distribution system model.
The Distribution State Estimator analysis module includes several detailed reports that can be further customized by the user. They provide insights on the solution by tabulating meaningful results such as estimated load values, meter measurements and calculated meter values. A series of quality indices is also available to help the engineer assess the accuracy of the solution:
- Normalized residuals
- Weighted residuals
- Normalized Lagrange multipliers
- Solution cost
- Measurement mismatches