Operation and Monitoring of Power Distribution and Supply Networks

The HIGH-LEIT Power Grid Topology function calculates the states of electrical power supply grids and visualises them via process images. If the state of the power grid changes, the Power Grid Topology function automatically carries out calculations and takes over the latest information. The calculations include all types of electrical transport and distribution networks as well as railway power supply systems (AC and DC).

Topological colouring variants enable special power grid analyses. Operators are thus able to view their power grids from different perspectives. Your required grid perspective can also be determined as part of the solution finding process.

Topological power grid states can be utilised in the ADMS processing mode and further processed using the function “topological arithmetic values”. This allows you to create added value that goes beyond the usual limit considerations.

Based on the power grid topology, you can carry out switching operations as part of your daily work in a safe and easy manner, including switching permission checks that go way beyond simple bay and system interlocks. The system warns operators against incorrect switching operations. In addition to a comprehensive basic library of switching permission checks, we can also provide specially configured checks for your use cases. Including, for instance, special switching conditions in special power grids ( e.g. industrial power grids).
Apart from single switching operations, this function also enables the safe and easy execution of typified switching sequences and works in the power grid, such as the exchange of busbars.

Topological markings and provisional features provide support for service and maintenance works. In the event of faults in the power grid, the power grid topology provides earth fault and short circuit localisation functions which evaluate information from the secondary protection devices in order to localise the fault location as precisely and quickly as possible.

In distribution networks with a sophisticated measuring infrastructure - e.g. high-voltage power grids - the State Estimation carries out the following online calculations: Active power, reactive power, voltage amount and voltage angle; it also recognizes and corrects faulty measured values and determines these values at grid points where no measurements take place. The State Estimation function utilises a complete Newton-Raphson method where the system of equations is completely rebuilt at each iteration step.

The (n-1) Grid Failure Calculation function ensures safety in enmeshed power grids. This calculation model serves for the assessment of a power grid with regard to equipment overloads and voltage limit violation of busbars if individual components of the power grid break down.
Distribution networks with a less sophisticated measuring infrastructure can be calculated online via the load-flow calculation function. The grid is continually monitored for overload and voltage limit violations, emitting alarms and providing visualisations.

Prior to each switching operation, the load-flow calculation carries out calculations and visualisation of potential component overload and voltage limit violations which are automatically included in the topological interlock check. The load-flow calculation can also be used in the simulation mode, enabling the operators to safely prepare extensive switching operations.

The load-flow calculation function also takes into account the producers of renewable energies and recognises re-feeds into higher voltage levels. The load model enables the mapping of volatile consumption behaviour.
In combination with a feed-in and consumption forecast, the forecast-based load-flow calculation can be used to calculate future operating conditions in advance. The system informs you about potential future bottlenecks. Thereby enabling you to initiate suitable countermeasures and check them beforehand in the simulation mode.

Calculation of short circuits is carried out on all nodes according to the Takahashi method. It is possible to make parallel calculations of 3-pole, 2-pole and 1-pole faults as well as 2-phase to earth faults, thus enabling visualization of the results of each type of error. Calculations are done in the positive-sequence, negative-sequence and zero-sequence system. The basis for these calculations is the IEC 60909 (DIN VDE 01202) standard “Calculation of Short-Circuit Currents in Three-Phase Current Grids”.

By setting potential fault locations in the simulation mode, users can calculate different short-circuit scenarios. The basic scope of this function also includes the calculation of double earth faults (two single-pole faults at different conductors and locations).

In the operation of power grids, several persons are involved in the process chain - from switching requests to the execution of switching operations through to evaluations in the form of switching records. The web-based function “Switching Request” supports operators at every single stage and enables the partial automation of grid operation.

In addition, the ACOS 7 series offers you a broad portfolio of telecontrol and automation technology. From our small and flexible ACOS 730 with different applications to our all-rounder, the ACOS 750 RTU.