• EN
  • Engineering and consulting services in the field of electrical networks

    The energy transition creates challenges for all systems, from the transmission grid to industrial networks.

    The paradigm shift in energy supply from large centralized generators to small distributed renewable generation plants is creating new challenges for both electrical grid operators and industrial customers.

    If operators and industrial customers want to be technologically prepared for the future, Iqony is exactly the right partner. The engineering and consulting company has over 40 years of experience in the field of electrical networks for system operators and industrial customers.

    What Iqony offers:

    Iqony’s services in the field of electrical networks include:

    • Modeling of electrical networks – from extra-high voltage to low voltage, including all standard components
    • Load flow calculations
    • Short-circuit calculations to VDE 0102 Part 0 (DIN EN 60909), IEC 60909, ANSI or ‘complete’
    • Dynamic simulations (RMS/EMT)
    • Stability analyses
    • Design/dimensioning of components
    • Creation and review of protection systems including selectivity analysis.
    • Arc flash analysis
    • Reliability considerations
    • Determination of network characteristics
    • Harmonics analysis
    • Design services for the electrical connection of thermal and renewable energy generation systems, and battery storage systems, in accordance with VDE application guidelines

    Technical feasibility and cost-effectiveness are always assessed in the calculations and additional services are offered. For example, an on-site inspection of the system is also carried out if necessary.

    Iqony always develops the model structure and possible operating scenarios in consultation with the customer.

    What use are network calculations?

    Network calculations are the cornerstone for the operation and expansion of electrical grids. Static network calculations are our day-to-day business. However, with the increased integration of energy from renewables, the integration of battery storage systems and large electrical loads such as industrial-scale heat pumps and electrically powered hot water generators and – often associated with this – the operation of networks closer to the utilization and stability limits, additional network calculations and analyses are becoming absolutely essential.

    Network calculations cover a wide range of areas, from the dimensioning of components to complex stability analyses. Static and dynamic network calculations can also be used to analyze the suitability of generation plants and loads for their integration into the public or industrial network. The following examples may serve to illustrate the broad range involved: a) Stability analysis of an industrial network when picking off the internal service requirement, b) Protection analysis including selectivity analysis and arc flash calculations for an industrial network, c) Optimum dimensioning of a transformer with on-load tap-changer, taking into account the extreme cases that occur during operation.

    Iqony uses the tried and tested DIgSILENT PowerFactory network calculation software, which can map all common components such as generators, transformers, lines and loads. Battery systems, photovoltaic systems and wind farms can also be included in the model. For dynamic simulations, controls such as voltage stabilizers and turbine controllers can be mapped. In practice, there are no limits to the modelling of open-loop or closed-loop control concepts. For the same reason, the complex environment with its diverse issues is also taken into account.

    Network calculations and analyses in detail

    The various network calculations and analyses are described in greater detail below.

    Modeling of electrical networks from extra-high voltage to low voltage including all common components. Virtually all common components such as generators, renewables systems, batteries, lines and cables, transformers and consumers can be modeled. Modeling also includes the implementation of controllers such as voltage stabilizers, turbine controllers and battery controllers. The level of detail for modeling components and controllers depends on the issue at hand.

    Load flow calculations are used, among other things, to dimension equipment or to identify bottlenecks and voltage limit violations in a network. For example, the cable cross-section required for the maximum operating current is calculated.

    Short-circuit calculations are performed in accordance with one of the following standards, depending on the requirements: VDE 0102 Part 0 (DIN EN 60909), IEC 60909, ANSI or ‘complete’. In addition to load flow calculations, short-circuit calculations are essential for dimensioning components. For example, switchgear must be designed for the maximum short-circuit currents that occur in order to prevent damage in the event of a fault. Short-circuit calculations are also an integral part of stability analyses in dynamic simulations, in which their influence on the generation units and consumers is analyzed. Calculation of the maximum and minimum short-circuit current also plays a central role in the protection and selectivity analysis.

    Dynamic simulations (RMS/EMT) are used to analyze processes in the time domain. For example, the influence of faults on the frequency and voltage curves against time can be analyzed. Another example would be the investigation of the behavior of a refinery network when power is taken off for internal demand. In all these simulations, dynamic characteristics such as the voltage and turbine controllers of conventional generation plants or the active and reactive power control of a battery system are also taken into account.

    Stability analyses focus on investigating whether the network (area) under investigation can be operated stably under all possible conditions. A rough distinction can be made between three categories: 1) frequency stability, 2) voltage stability, and 3) angle stability. In most cases, several categories are considered simultaneously in order to obtain a comprehensive picture of stability.

    Creation and review of protection strategies including selectivity analysis. For new installations, a specific protection system design must be drawn up right from the start. For existing systems, a review of the protection strategy has to be carried out in the event of significant modifications or extensions. The creation and review always includes a selectivity analysis in order to identify any selectivity problems and rectify them by adjusting the parameters.

    Arc flash analysis. Arc flash calculations are carried out in order to determine the arc flash hazard distance and incident energy to which workers may be exposed while working on or near electrical equipment [IEEE1584-2002]. Different calculation methods are used for this: IEEE-1584 - 2002, IEEE-1584 - 2018, NFPA 70E, and DGUV 203-077.
    Knowledge of the arc fault calculation is of great importance for dimensioning electrical systems, selecting suitable protective devices, assessing the short-circuit risk and planning protective measures to minimize the effects of short circuits, such as fire protection and determining the requirements for personal protective equipment (PPE).

    Reliability assessments aim to evaluate the reliability of the network and identify measures for improvement in order to ensure safe and stable operation. Various factors such as the failure rate of components, the effects of environmental influences and the effectiveness of protective measures are taken into account.

    Determination of grid characteristics is used to assess the reliability of electrical grids. For example, the average number of interruptions and their duration per customer and year are calculated. As part of the analysis, measures to improve reliability are developed where necessary.

    Harmonics analyses are used to evaluate the distortion of the voltage and current caused by harmonics and whether the distortion values are below the limits (IEC 61000-3-6 and IEC 61000-2-4 standards are generally used here). Components that generate harmonics, such as converters, are taken into account and measures to reduce harmonics are developed if necessary.

    Planning services for the electrical connection of thermal and renewables-based energy generation systems, and battery storage systems, in accordance with VDE application guidelines. Generation systems must meet the requirements of the VDE 41xx guidelines. Iqony can support the customer in both the design and the certification processes. In the design phase, for example, a simulation can be used to assess whether the requirements can be met. In the complex certification process, Iqony can coordinate with the certifier, manufacturer and customer and provide support with its extensive know-how.

    Selected references

    • Network stability calculation for the TotalEnergies refinery network in Leuna
    • Load flow calculations, short-circuit calculations, dynamic simulations and stability calculations for STEAG’s refinery power plant in Leuna
    • Load flow and short-circuit calculations to optimize the system layout with regard to switchgear, integration of large heat pumps, electric boilers and short-circuit current limiters for Stadtwerke Duisburg and Entsorgungsgesellschaft Krefeld GmbH
    • Load flow, short-circuit calculations, protection and selectivity analysis for RAG AG’s well water basin in Reden, the Saarlouis combined heat and power plant, mobile heating centers in Völklingen, AVA-Velsen waste to energy plant, Fresenius Medical Care-St. Wendel, Sömmerda 2-3 CHP plants, iKWK-Camphausen district heating supply
    • Protection, selectivity and arc fault analysis for BP’s Horst and Scholven refineries, Gelsenkirchen
    • Dimensioning of the HV network connections of various data centers
    • Protection and selectivity analyses of various data centers and their HV network connections
    • New planning for 110 kV plant feed-in to replace Evonik Industries’ 35 kV feed-in at the Herne plant
    • Network calculations for Evonik Industries’ plant expansion in Antwerp
    • Development of the protection concept for Evonik Industries’ medium-voltage network at the Worms plant
    • Basic study on target network planning for BP/Ineos at the Cologne plant
    • Short-circuit current calculation of the Hoesch AG steelworks in Hohenlimburg
    • Investigation of the black start capability of CCGT plants