In parallel with this, distribution utilities began to roll out Supervisory Control and Data Acquisition (SCADA) systems, initially only at their higher voltage substations.
DMSs access real-time data and provide all information on a single console at the control centre in an integrated manner.
In the UK, by contrast, the much denser and more meshed network topologies, combined with stronger Health & Safety regulation, had led to early centralisation of high-voltage switching operations, initially using paper records and schematic diagrams printed onto large wallboards which were 'dressed' with magnetic symbols to show the current running states.
These DMSs required even more detailed component/connectivity models and schematics than those needed by early OMSs as every possible isolation and earthing point on the networks had to be included.
State estimators allow the calculation of these variables of interest with high confidence despite the facts that the measurements may be corrupted by noise, or could be missing or inaccurate.
The time constants are sufficiently fast so that system dynamics decay away quickly (with respect to measurement frequency).
The load flow study usually uses simplified notations like a single-line diagram and focuses on various forms of AC power rather than voltage and current.
Capacitor banks manage voltage by “generating” reactive power, and have thus far been the primary tools through which true Volt/VAR control is carried out.
The plan will give a required tap position and capacitor switching state to ensure the voltage stays close to its nominal value and thus optimize Volt-VAR control function for the utility.
Beyond maintaining a stable voltage profile, VVC has potential benefits for the ampacity (current-carrying capacity) of power lines.
Electric Distribution Systems have long stretches of transmission line, multiple injection points and fluctuating consumer demand.
Instability usually arises from power system oscillations due to faults, peak deficit or protection failures.
Distribution load shedding and restoration schemes play a vital role in emergency operation and control in any utility.
An automated Load Shedding Application detects predetermined trigger conditions in the distribution network and performs predefined sets of control actions, such as opening or closing non-critical feeders, reconfiguring downstream distribution or sources of injections, or performing a tap control at a transformer.
In a non-automated system, awareness and manual operator intervention play a key role in trouble mitigation.
Reduced outage time duration to customer, shall improve over all utility reliability indices hence FMSR or automated switching applications plays an important role.
The DMS application utilizes switching management application for this, the losses minimization problem is solved by the optimal power flow algorithm and switching plans are created similar to above function Distribution Load Forecasting (DLF) provides a structured interface for creating, managing and analyzing load forecasts.
To forecast load precisely throughout a year, various external factors including weathers, solar radiation, population, per capita gross domestic product seasons and holidays need to be considered.
For example, in the winter season, average wind chill factor could be added as an explanatory variable in addition to those used in the summer model.
Various predictive models have been developed for load forecasting based on various techniques like multiple regression, exponential smoothing, iterative reweighted least-squares, adaptive load forecasting, stochastic time series, fuzzy logic, neural networks and knowledge based expert systems.
Quite often, each of these functional modules need to exchange periodic or real time data with each other for assessing present operation condition of the network, workflows and resources (like crew, assets, etc.).
If the different functional modules are operating in a non-standard environment and uses custom APIs and database interfaces, the engineering effort for managing shall become too large.
Soon it will become difficult to manage the growing changes and additions which would result in making system integrations non- functional.
Hence utilities cannot make use of the complete benefit of functional modules and in some cases; the systems may even need to be migrated to suitable environments with very high costs.
IEC 61968 recommends that system interfaces of a compliant utility inter-application infrastructure be defined using Unified Modelling Language (UML).
UML includes a set of graphic notation techniques that can be used to create visual models of object-oriented software-intensive systems.