|
9 achievement(s) found As part of the project for the realization of a second French aircraft carrier, PA2, in the "All Electrical Ship" version, it was necessary to validate the design choices for the electrical power grid of the ship and to verify that all the standard constraints could be met, particularly from the point of view of the dynamic stability of the power grid. [...]Because of changes in power consumption and the need for redundant power supply to FPSO (Floating Production Storage and Offloading Unit), it is strongly of interest to electrically interconnect units present in the same area using undersea cables. However, the impact on electrical plant in terms of dynamic stability, short circuit currents and harmonics must be analyzed in detail. [...]Prior to the stability study described here, CAPSIM had produced power flow calculations and calculations of the short-circuit currents for the operator of an industrial electrical power grid. These calculations had been used to validate the sizing of equipment and to put in place a protection plan for the grid.
The turbine generators for that network could operate either independently or coupled to the public distribution grid and simulations were carried out for the two operating configurations. Events acting on the islanded configuration could more easily result in a grid instability because the short-circuit power of the sources was lower.
The objective of the study was to validate the protection plan put in place by CAPSIM as well as to perform a study of the dynamic behaviour of the turbine generators when subject to disruption events. The outdated nature of the generators and their excitation raised questions regarding their robustness and their effectiveness when faced with such events.
[...]On an existing oil installation consisting of several platforms, the production of electricity and the power supply for water injection pumps on the platforms was being directly realized by ageing turbine generators. The obsolescence of this equipment led the operator to develop an electricity power grid using a shore-based electricity plant and an underwater connecting cable (between 20 and 30 km long at a depth of 30 m) linking the plant to the various platforms.
As part of this renovation project, it was necessary to evaluate the impact of normal transient events (load connection, load shedding, connection of the generator to the grid) and incidental events (short-circuit, loss of the generator, etc.) on the electrical power supply to the platforms. [...]In order to be able to connect a cogeneration power plant to the public HVB grid, our customer needed to be able to demonstrate to its energy supplier that its installation complied with their defined specifications. In particular, they needed to provide the following simulations: - Constructive reactance capacity
- Dynamic behaviour of the voltage regulation and stability under small movements
- Stability under load transfer
- Stability under short-circuit
- Behaviour of the facility following a dip in voltage
- Behaviour of the voltage under variation in frequency
[...]The French law of 23 April 2008, which specifies the conditions for connecting generating units to the public distribution grid, changed the requirements relating to disrupted voltage regimes on public grids.
Under certain conditions, the electricity producer must now leave its generating unit connected during fluctuations in frequency and voltage on the grid, where as previously it had been requested to uncouple the generator in such situations.
This part of the law applies to all generating units greater than 5 MW and may also apply to new installations with a modified existing installation or with installations for which the energy repurchasing contract comes to an end.
Article 14 sets a voltage dip profile at the point of delivery which must be tolerated without decoupling by the generating unit (see figure below).
Our client wished to study the possible impact of this voltage dip on its equipment and, in particular, the risk of instability and loss of synchronization on the generator.
[...]A distribution system operator wanted to assess the impacts on a urban grid of massive integration of decentralized power generation (solar plants and hydropower) and new consummers (electric vehicles, high power electrical PAC ...) .
The studied urban distribution grid is composed with three MV loops fed by two HV substations. Each loop feeds a dozen HV/LV distribution stations for industrial and residential uses.
This prospective study was therefore to evaluate the maximal penetration rate of renewable power and new consumers. The main issues to be addressed are the network stability and power quality. [...]For the construction project of the first ever wind farm in West Africa, Capsim was chosen to perform a study regarding the impact and the compatibility of a 25MW wind farm on the national power grid of Togo.
The main aim was to check whether the integration of the wind farm on the electrical grid was possible or not and also to define the necessary conditions for stability when the farm is connected. The substation to which the installation will be connected is managed by the national electrical grid company. This substation is also connected to the public electrical transmission grid managed by a neighbouring country operator. [...]For the case of energetic development in sub-Saharan Africa, the construction of a 33MWp photovoltaic power station is planned. This future power station will be connected to the national electricity transmission grid of the country. This electrical grid can be interconnected with those of 2 neighbouring countries. This grid possesses several electrical thermal and hydraulic generation power units across the country.
In this context, Capsim was sought by investors and the network operator for the following: - Analysis of the grid stability during power injection by the future power station on the interconnected national grid. In this particular case, the intermittence of the photovoltaic power station and the weaknesses already present in the current network (low production capacity, regular power cuts and black outs) are to be considered,
- Assistance in technical specification precisions to include in the tender files of the key-in-hand construction contract,
- Analysis of issues regarding the extension of the power station or the integration of additional power stations into the grid.
[...] | 
