Network Calculations - Calculation of distribution grids

Calculation of distribution grids

Challenges such as reverse power flow and voltage rise due to distributed generation as well as the integration of electromobility have led to a significantly higher effort in the planning and operation of distribution grids. Sophisticated and comprehensive grid optimization tools are required to perform the associated studies.

Load flow calculation

Choice of load flow calculation methods including a full AC Newton-Raphson method and a linear DC load flow. Multiple superimposed iteration stages ensure convergence of load flow calculation under all conditions. The load flow calculation can be performed considering the stochastic consumption behavior of loads. Fast DC load flow calculation using a linear system eliminates the need for iterations.

Protection functions

An extensive vendor-specific relay library is available and can be used in steady-state and dynamic simulations. A range of protection functions is supported, including overcurrent time protection, distance protection, differential protection, directional protection, overvoltage and undervoltage protection, overfrequency and underfrequency protection, etc. Graphical representations of protection device characteristics such as overcurrent-time diagrams or diagrams for differential protection are available. Selected protection parameters can be output to tables and exported for further review. Step-by-step execution of short-circuit calculations for simulation of fault clearing and relay behavior is possible.

Selectivity

Step-by-step execution of short-circuit calculations for simulation of fault clearing and relay behavior and selectivity.

Short-circuit calculations for AC and DC networks according to IEC and VDE standards.

The short circuit calculation allows consideration for single and multiple faults. The used short-circuit calculation supports the short-circuit calculation with different representations and calculation methods according to a number of international standards (also according to VDE 0102) as well as the superposition method. Here, the short-circuit calculations determine the occurring short-circuit currents for a specific operating point of the network, without the usual simplifications or assumptions.