44 achievement(s) found
As part of the construction of the Severstal industrial site in Russia, Capsim carried out a study of the protection plan of all the HV and LV electrical grids. [...]
As part of the connection of a 63/20 kV transformer station supplying a gas compression plant, CAPSIM investigated the risk of ferroresonance on the site. [...]
This project involved designing an islanded system supplied by a collection of multiple renewable electrical energy sources . The inhomogeneous character of the sources (wind turbines, fuel cells, diesel generators, etc.) required a suitable control system to be defined. [...]
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. [...]
The objective of this study was to define the Specification for modifications to be applied to an industrial emergency power unit so that it could fulfil specific requirements, notably in terms of the safety of the target application. This generator, classed as "important safety equipment", fulfils an emergency power supply function for a test nuclear reactor.
The study therefore involved defining the additional tests or studies which will make it possible to qualify the diesel generator unit with respect to these requirements. [...]
As part of a gas compression plant installation project, the customer needed to validate and justify the sizing of the earth network in a way that complied with the standard in force for the step and touch voltages. [...]
When undertaking its ship-construction activities, our customer is subject to the requirements of reliability standards and must design its ships in such a way that they are always able to conserve 50% of the propulsive power and to retain the capacity for its control in the event of a single failure. CAPSIM was therefore given responsibility for defining a methodology capable of taking into account and guaranteeing that this constraint was met from the ship's design phase onwards. [...]
As part of a new town pilot study (eco-city concept), it was necessary to carry out a basic pilot project for the electricity distribution grid. [...]
In order to accompany the nuclear fusion research activities of the ITER project, it has proved necessary to improve the Japanese JT60 fusion reactor (tokamak). Capsim has participated in the design of the project by modelling all of the electrical supply infrastructure and by simulating the current draw necessary for a plasma shot.
The objective was to evaluate the impact in terms of the active power, reactive power, frequency and voltage of the network, and to verify the correct sizing of the equipment that makes up the system. [...]
The system studied is composed of vertical rods whose lower ends are immersed in a liquid under pressure. Vertical displacement of the rods is achieved using grippers activated by induction coils.
In order to identify the failure risks of the system as part of the modification of its control system, it was necessary to evaluate the influence of the various parameters on the displacement controls for these rods. To achieve this, a model was produced using PSIM software. [...]
The MOSARE project was developed by CAPSIM in response to the following needs:
- To have a tool available which can increase the technical expertise on new programmes,
- To study the impact of new technologies proposed by industrial companies,
- To produce expert reports on the fleet already in service.
ITER is a very large-scale international scientific experiment for demonstrating the scientific and technological feasibility of electricity production using energy from nuclear fusion and leading to its industrial and commercial production.
CAPSIM is undertaking a project to assist its customer, ITER ORGANIZATION, in the selection of architecture and in sizing the HVA and HVB electrical power grids.
The study includes performing the initial sizing of electrical equipment that will in future be used for the grid to auxiliary systems of the ITER facility.
This grid, known as the Steady State Electrical Power Network (SSEPN), is connected to a double circuit 400 kV line. It is able to supply the ITER auxiliary systems, i.e. cooling, cryogenics and pumping systems, etc.
The total power of the installed loads is 160 MW and 80% have medium voltage induction motors.
The network contains high/medium voltage transformers supplying the principal busbars. At each start up, the required electrical power is distributed to the various production and generation sectors via the circuit breakers, cables and step-down transformers. [...]
This study involved determining the influence of the tolerances applied to the various parameters of a motor driven pump and its power supply system, on its capacity to change from a low speed regime to a high-speed regime. This equipment delivers a cooling function for a nuclear application. [...]
Over the past few years, technological developments in power electronics have allowed locomotives to be powered via a new generation of converters. One consequence of the arrival of this new equipment has been the appearance of harmonic currents which circulate in electric railway lines at harmonic values which had not previously been present.
It is therefore necessary to be able to ascertain whether or not, in certain configurations, it was possible for these currents to create undesirable overvoltage incidents, leading to cuts in the power supply and possibly damaging equipment. [...]
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. [...]
The industrial site studied was constructed in the 1950s and has been subject to many changes. The electricity distribution grid on the site contains several autonomous sources (turbine generators), distributed at various points on the HVA and HVB grids. The function of these generators is to supply the priority units in the event of a power grid problem (internal or external to the site).
The site was recently subject to two major incidents in less than six months on the main HVA distribution grid, incidents which resulted in the loss of supply to the priority units and the start-up of the autonomous sources supplying power to these units. Following these incidents, the operator undertook a campaign to modernize the excitation regulation for the turbine generators.
This involved allowing the customer to understand the dynamic behaviour of its autonomous sources in the event of a transient event on the grid. The initial objective was to analyze and validate the causes of the incident. The second objective was to analyze the influence of modifications made to the excitation regulation and to detect the operating limits to impose on the autonomous sources after modification. [...]
The site studied was a very large facility undergoing reconversion that would result in it accommodating new consumption units and new generators (biomass plant) using the existing electrical grid. In this configuration, the operator, via a suitable structure, must ensure the supply of utilities (steam, electricity, etc.) for all of the industrial units present on the site. The realization of this service relies directly on the concepts of availability and reliability of the grids and the generators.
In this context, the project involved producing:
- An audit of the electrical grid consisting of identification of the strong and weak points of the HVA distribution network, in order to make the HVA grid reliable,
- A complete review of the protection plan in light of the results from the dynamic study and the replacement of analogue protection relays by a new generation digital relays.
As part of a program for maintaining the operational condition of ships, the customer wished to study the feasibility of replacing the power converter sets which used rotary equipment with a solution based on static converters.
The power converter sets, consisting of a mechanically linked "direct current machine + synchronous machine", are reversible converter units which allow conversion of the AC 440/60 Hz power network to the 198 V DC battery network. This equipment, of old design, was ageing and becoming obsolete. Breakdown detection had become increasingly complex and the adjustment of the control loops as well as the requalification tests were increasingly tiresome.
The project therefore involved producing a functional analysis of the existing system in order to redefine the functions associated with the power generation system independently of the technology used. The functional analysis was to be used as the basis of a search for new technical solutions to respond to the requirement and to consult with suppliers. This consultation phase was followed a by technical assistance phase to analyze the feasibility of the proposed solutions. [...]
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. [...]
As part of the electrical connection of a wind farm, the future producer needed to comply with the latest regulations, in particular the French law of 23 April 2008. This law relates to the technical requirements of the design and operation of an electricity producing facility for connection to the public electricity distribution grid at low or medium voltage and imposes certain constraints in terms of the voltage plan to be observed at the common coupling point (point of delivery).
The producer must then study the adjustments and set points on the machines to satisfy the voltage plan at the common coupling point imposed by the distributor (contractual voltage and reactive production and absorption). [...]
As part of the development of a simulation platform intended for use by helicopter pilot crews, a representative model of the electrical power grid for the pilot and the other systems which can be simulated in real-time was required.
CAPSIM was asked by its customer to develop this real-time model of the helicopter's electrical power grid containing the generators, batteries, DC distribution system and the various power consumption units.
The "real-time" constraint led to the use of a sufficiently rapid discrete solver with fixed time step, the electrical equipment and the power grid being developed in the AMESim environment.
This, therefore, involved studying the physical and behavioural phenomena to be modelled and proposing an adequate power grid model which could be run in real-time. [...]
The customer wished to understand the causes of a fault observed on the output of a 15 kV capacitor bank which had caused its removal from service. It also wanted CAPSIM to carry out a reactive compensation study to avoid additional invoicing from its energy supplier. [...]
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.
The distribution grid of the Arsenal de Toulon is one of the largest private grids in France with more than 150 transformer stations.
Because of the obsolescence of certain protection devices and the limitations of the current protection plan, the management sought assistance to successfully complete the work with a view to updating the protection plan for the 10 kV - 50 Hz high voltage grid supplying its site. Moreover, it wished to improve the reactive energy compensation of the network in order to reduce its energy bill. [...]
The operator of the nuclear power station wanted to be able to predict the impact, from an electrical point of view, of particular configurations of the grid, while avoiding the need to perform on-site tests which are costly and complex to set up. [...]
This study involved sizing 156 current transformers (CT) which will be installed on the HVA grid of an industrial site in the Middle East.
Sizing the current transformers is a critical step in the correct operation of the protection plan for an industrial grid. An unsuitable current transform may result in a protection device malfunctioning.
The project also involved sizing the single-pole tori used for protection at maximum earth current. [...]
is a very large-scale international scientific project for demonstrating the scientific and technological feasibility of electricity production using energy from nuclear fusion and leading to its industrial and commercial production.
With this goal, a magnetic plasma confinement system called a tokamak has been constructed using superconducting coils. These coils are supplied on a 66 kV and 22 kV distribution grid via AC/DC thyristor converters (12 pulses). This grid is supplied by three 3-winding transformers, 400kV/66kV/22kV, allowing it to be connected to the RTD grid on a dedicated 400 kV line.
The power consumption of the coils fluctuates greatly during a plasma shot and, in particular, during its initiation and extinction. The impact of these power fluctuations on the grid needed to be estimated in order to validate adherence to the connection constraints of the ITER grid to the supplier distribution grid including limits for active power, reactive power and voltage levels of the various buses.
Hence, the requirement expressed by ITER was to obtain a tool which could simulate the voltage plan of the grid and the power flows throughout the duration of a plasma shot scenario. [...]
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. [...]
The Transient Recovery Voltage (TRV) is the voltage which appears across electrical equipment shortly after a current interruption. The waveform of the recovery voltage actually depends on the circuit configuration (inductive or capacitive nature). For example, a circuit breaker should be able to interrupt a given current for any recovery voltage provided that this value does not exceed its assigned TRV value (this TRV value is specified in the 61071 IEC standards).
The replacement of a HV circuit breaker, particularly in the case of replacement of SF6 circuit breakers by vacuum ones, requires the TRV calculations to be rechecked.
It is necessary to check that the generated overvoltages respect both the insulation levels of the present network equipment and the IEC assigned values of the breaking device. If the overvoltage levels are too high, then the installation overvoltage protection equipment should be considered (for example capacitors which reduce the rising edge steepness of overvoltages, RC circuits, surge arresters...). [...]
When a transformer is energised, two main phenomena occur: an inrush current and a voltage drop at the primary side. The amplitudes of these two phenomena depend greatly on the remanent (or residual) magnetic flux, the transformer saturation curve and the instant of energisation. Before being commissioned, it should be checked whether the transformer is compliant or not with the local electrical grid standards.
Before the commissioning of a 40MVA power transformer on the UK electrical grid (33kV), the customer wanted to check if the transformer complies with the national standards in terms of voltage drops (« P28: Planning limits for voltage fluctuations caused by Industrial, Commercial and Domestic equipment in the United Kingdom ») during its energisation process.
If the voltage drop exceeds the limits, the transformer will not be compliant and therefore unfit to be commissioned. Mitigation devices should be installed in order to reduce the voltage. [...]
For the case of the connection of a power station to the French HV network (HTA RTE), the PV power generation company must prove that its infrastructure will not cause instability on the grid. For this situation, RTE (Réseau de Transport d’Electricité) defined the specifications regarding the constructive capacities to be respected. These specifications are adapted to this case in terms of the power station’s “size”, its location on the power grid and the type of electricity generation (wind turbines, photovoltaic cells).
The PV power generation company must submit a technical document consisting of simulation analysis files and test files in order to check the respect of the connection specifications.
The aim of the study was to simulate the connection of a 33MW photovoltaic power station to the 63kV HV grid.
Moreover, during this study, CAPSIM was asked to analyse the primary voltage regulation system which controls the active power of the solar park by acting on the photovoltaic inverters set point. [...]
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. [...]
When a transformer is energised, two main phenomena occur; an inrush current and a resulting voltage drop at its primary side. The amplitudes of these two phenomena depend greatly on the remnant (or residual) magnetic flux, the transformer’s saturation curve and the instant of energisation. Before being commissioned, it should be checked whether the transformer is compliant or not with the local electrical grid standards.
For the case of the connection of a wind power station to the French RTE grid (90kV), the client wished to consider the different energisation (simultaneous or sequential energisation) strategies (at the 21kV level) of the wind turbine transformers which respect the transient voltage drop limit (5%) at the connection point. [...]
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.
The breakthroughs in the field of power electronics regarding on one hand photovoltaic panels and on the other hand enable to consider higher levels of DC distribution voltage within PV power stations. Indeed, for a given photovoltaic power, the increase in distribution voltage allows decreasing the current to be delivered to the network, and therefore to limit the cable distances required and distribution losses. These advantages must however be compared to technical-economic issues that an increase in distribution voltage may represent: availability of equipment from manufacturers, higher purchase costs, technical uncertainties…).
Our client requested us for quantifying the technical-economic impact of increasing the DC voltage to 1500V, and then to 3000V (initially planned to be at 1000V) of their several MWs PV power station. [...]
The hybridation of Diesel power stations with renewable energy sources is interesting in the case of isolated electrical grids which are very far from any transmission grid.
The aim of this project was to implement hybridation of power stations feeding towns isolated from any electrical grid (micro-grid in this case) in Oriental Siberia and in the Kamchatka peninsula (in Russia) via the addition of photovoltaic power stations, wind farms, and energy storage systems.
Indeed, the conditions of extreme cold and high supplying fuel distances to these areas may lead to high electricity production costs, which could be significantly decreased by means of hybridation.
The network user of these isolated electrical grid wished therefore to:
- Implement an energy management strategy so as to directly control the equipment of the hybrid power stations,
- Create a simulation tool allowing the validation of the optimal operation of the power stations as well as the optimisation of the equipment sizing.
The project consists in the construction of a 52MW PV power station in the near future in Israel. This PV power station will be connected to the 161kV HV electrical grid of the country.
In this context, CAPSIM was chosen in order to perform the following analyses on the future PV station:
- Verification of the harmonic levels produced by the PV + inverters at the connection point in the different possible network configurations of the future installation,
- Observation of the impact of the capacitor bank switching (in terms of overvoltage and switching current) on the future PV installation and on the equipment,
- Study of TRVs (transient recovery voltage) across the circuit breakers during normal operations and following faults such as short-circuits.
The customer wished to be able to create and exploit an ETAP model of his LV (28V) DC network so as to study the electrical behavior in steady network conditions as well as during short-circuits.
CAPSIM was therefore requested for this mission for its expertise and knowledge of networks under strong technical and regulatory constraints (civilian and military nuclear, offshore rigs, complex scientific equipment, etc...) and its knowledge regarding electrical calculation tools. [...]
Following the commissioning of the all electric ship’s power station, a phenomenon active power “pumping” (of several MW) between 2 diesel generators has been observed. This phenomenon is characterised by active power transfer in both ways from one diesel generator to another; and is likely to cause a malfunction of the control system as well as an accelerated deterioration of the diesel generators themselves. The network operator wishes to identify the causes of this issue and to solve this problem. [...]
Soon after the commissioning of a 3MVA diesel generator on a site, degradations and tears were noticed in the mechanical coupling between the diesel engine and the alternator. The expert checking on the mechanical coupling did not show any fault on the deteriorations.
The network manager therefore requested CAPSIM to do a diagnostic based on numerical simulations. [...]
For the extension of the EDF Saint Raphael source substation, EDF wished to validate the sizing of the earthing system of the substation. [...]
Client’s project has to be in compliance with a requested level of reliability, availability and maintainability. A complete Reliability report must be carried out to prove that the installation design is in compliance with the expected reliability. [...]