This ‘Power Systems Studies’ tender concerns the performance of studies (and provision of study reports, models etc.) for pre-design, detailed design and grid compliance purposes. These studies may be performed for both Onshore and Offshore Wind Power Plant Projects.
Pre-design studies are focused on main component rating such as cables, transformers, switchgear and compensation equipment and are needed to identify basic grid code compliance. Studies may include:
1. Loss calculations.
2. PQ capability studies.
3. Voltage and frequency range studies.
4. Harmonic studies.
5. Short circuit capability studies.
The results from these studies are used by Vattenfall to:
1. Evaluate the business case by incorporating the right balance between inter array losses and cable costs.
2. Determine the proper split between compensation equipment and turbine performance (especially for PQ capability), enabling the setting of project specific requirements for tender material.
3. Evaluate the Turbine Electrical Performance in order to optimize the system.
Detailed design studies are primarily focused on protection requirements and may include:
1. Studying the short circuit protection and relay setting requirements.
2. Studying the insulation coordination for various operation aspects.
3. Studying the energisation of single turbines and arrays.
4. Studying the disconnection of Turbines and arrays.
5. Studying temporary over-voltage (especially for over flux and heating).
6. Harmonic emission studies (for design of potential grid filters).
7. Harmonic and sub-harmonic resonance studies.
8. Control stability studies (especially reactive power control response).
Results from these studies are used to complete and validate the design.
Grid compliance studies are required to prove compliance to grid code requirements. Most studies are concentrated around the turbine dynamic and transient performance such as:
1. Studying the Voltage and Frequency Ranges.
2. Studying Power and reactive power control performance.
3. Studying LVRT performance.
4. Studying Harmonics.
5. Studying Protection Setting.
6. Etc.
Results from these studies are used to evaluate the interaction between turbines, electrical infrastructure, substation power components, power transmission and the power grid in order to evaluate influence on grid stability and electromagnetic transients within the wind power plant.
Vattenfall's Wind Power Plant Projects will be steered mainly from Vattenfall's London (UK), Kolding (DK) or Hamburg (GER) offices and potentially Amsterdam (NL) and Solna (SE). Although the majority of work will take place at Contractor's offices travel to Vattenfall's offices and other locations within Northern Europe will be required.