Engineering and consulting services in the field of electrical networks

Modelling of electrical networks from extra-high voltage to low voltage, including all standard components. Virtually all common components, such as generators, renewable energy sources, batteries, lines and cables, transformers and consumers, can be represented. Modelling also includes the implementation of control systems such as voltage regulators, turbine controllers and battery controllers. However, the level of detail for modelling components and controllers depends on the specific issue at hand.

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

Short-circuit calculations are performed in accordance with one of the following standards, depending on requirements: VDE 0102 Part 0 (DIN EN 60909), IEC 60909, ANSI or 'complete'. Short-circuit calculations are essential for dimensioning components, alongside load flow calculations. For example, switchgear must be designed for the maximum short-circuit currents that may 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 generation units and consumers is analysed. The calculation of the maximum and minimum short-circuit current also plays a central role in protection and selectivity analysis.

Dynamic simulations (RMS/EMT) are used to analyse processes in the time domain. For example, the influence of faults on the frequency and voltage curve over time can be analysed. Another example would be to investigate the behaviour of a refinery network when intercepting for internal use. All these simulations also take into account dynamic characteristics such as the voltage and turbine controllers of conventional generation plants or the active and reactive power control of a battery system.

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, 3) angle stability. In most cases, several categories are considered simultaneously in order to obtain a comprehensive picture of stability.

For new installations, a specific protection concept must be drawn up at the outset. For existing installations, the protection concept must be reviewed in the event of significant modifications or extensions. The creation and review always includes a selectivity analysis to identify any selectivity problems and remedy them by adjusting parameters.

Arc flash calculations are performed to "determine the arc flash hazard distance and incident energy to which employees may be exposed while working on or near electrical equipment" [IEEE1584-2002]. Various calculation methods are used for this purpose: IEEE-1584 - 2002, IEEE-1584 - 2018, NFPA 70E, DGUV 203-077. Knowledge of arc flash calculation is of great importance for the dimensioning of electrical installations, the selection of suitable protective equipment, the assessment of short-circuit risk and the planning of protective measures to minimise the effects of short circuits, such as fire protection and 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 are taken into account, such as the failure rate of components, the effects of environmental influences and the effectiveness of protective measures.

Determining network key figures serves to evaluate the reliability of electrical networks. This involves calculating, for example, the average number of interruptions and their duration per customer per year. In the course of the analysis, measures for improving reliability are developed where necessary.

Harmonic analyses are used to evaluate the distortion of voltage and current caused by harmonics and to determine whether the distortion values are below the limit values (as a rule, the standards IEC 61000-3-6 and IEC 61000-2-4 are used here). Harmonic-generating components such as converters are taken into account and, if necessary, measures to reduce harmonics are developed.

Planning services for the electrical connection of thermal and renewable energy generation systems, as well as battery storage systems, in accordance with VDE application guidelines. Generation systems must meet the requirements of the VDE 41xx guidelines. Iqony can support customers in both the planning and certification processes. During the planning phase, for example, simulations 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 expertise.