Itemization procedure

The Electrotechnical Properties Verification Ordinance (NELEV) requires that generation systems meet the minimum technical requirements and are tested by a certification body. This procedure offers a customized test for systems that cannot follow the standard procedures with unit or system certificates (A and B). It is used in particular for large power plants, custom-built systems or older systems.

Yes, a distinction is made between the simplified individual verification procedure system certificate C1 and the individual verification procedure with a system certificate C2.

The C1 system certificate is used for complex, large-scale or customized systems (greater than 950 kW) that require a detailed technical inspection.

Features of the C1 procedure:

• Comprehensive creation of a simulation model that depicts the entire system in detail.
• Detailed measurements and validations after commissioning to ensure consistency with the simulation results.
• Long-term monitoring and model validation through the use of fault recorders.

This differentiation makes it possible to adapt the testing effort to the requirements of the respective system in order to ensure an efficient verification process.

The simplified procedure with a C2 system certificate is used for smaller (up to 950 kW connected load) or less complex systems.

Features of the C2 process:

• Reduced scope of verifications, especially in modeling and simulations.
• Focus on basic grid compatibility and compliance with minimum requirements.
• Less testing and documentation effort.

Systems that are eligible for the individual verification procedure are often complex or individual energy generation systems with special requirements. These include, for example

These systems are often characterized by their high performance, individual requirements or special operating conditions that make a standardized verification procedure impractical.

Before the system is put into operation, it is simulated in a simulation environment in order to test its electrotechnical properties. The planning documents are used to create simulation models that analyze the system’s impact on the power grid.

Important test areas:

• Network compatibility (e.g. voltage changes, flicker, harmonics)
• Power provision (active and reactive power, control functions)
• Stability of the system in the event of a fault

The system certificate C must be submitted to the grid operator before the system is commissioned. After checking, the grid operator issues a provisional operating permit.

As soon as the system is in operation, real measurements are carried out to validate the simulation models and verify requirements.

These include, for example:

• Functional tests and protection tests
• Measurements of grid perturbations, active and reactive power
• Validation of the behavior of the system under different operating conditions

The results of the measurements are compared with the simulations. If adjustments are necessary, the simulation model is updated. The extended declaration of conformity can only be issued if all requirements are met.

After acceptance, the operation of the system is monitored. A fault recorder regularly records voltage events, which are compared with the simulation model. The aim is to ensure that the system functions reliably in the long term and meets the grid requirements.

The individual verification procedure also requires the operator to have in-depth knowledge of system control, grid protection, generators and other technical details. We therefore recommend that all parties involved are closely involved in the planning phase and contractually obligated to ensure that the suppliers provide comprehensive technical support.

With our experience in certification processes, we support you from the first simulation to the monitoring of your system – on time and professionally. Do you have any questions or need support? We will be happy to advise you!