Documents
Description of the Cell pilot project:
Throughout the world, there is a trend towards renewable as well as decentralized energy generation. Among the key technologies, we find the following:
- Wind turbines
- Photovoltaic systems
- Biomass systems
- Fuel cells
- Stirling engines
- Mini-hydro power stations or other minor sources of renewable energy.
- local utilization of waste heat from combusting primary energy for power generation with gas turbines, micro-turbines or fuel cells, where small installations are used for combined heat and power production
“ In some countries, such as Denmark, this process has already come a long way ”
Together with demand-side management (controllable loads), these technologies will play an important role in the future energy generation. In some countries, such as in Denmark, this process has already come a long way. energynautics is actively involved in this process through several projects in Denmark. On the one hand, decentralized power production can reduce potential requirements for expanding the traditional systems (new transmission lines). On the other hand, the controlling of a large number of decentralized energy generators may pose new challenges regarding the safe and efficient operation as well as the controlling of power networks.
One answer to these challenges may be found in new IT-based technologies which are able to remotely control renewable and decentralized energy production. Among these technologies, we find smart-grids, micro-grids, cells and virtual power plants.
Example: The Cell pilot project
Energinet.dk, the Danish transmission network operator, owns and operates the high-voltage network in Denmark. Denmark is worldwide leading regarding the network integration of renewable and decentralized energy sources. Currently, wind power corresponds to about 25% of total consumption and the traditional power production throughout the country is, to a large extent, based on decentralized generators with CHP installation.
“ Development of an inno-
vative network management technology ”
In order to achieve an even larger proportion of wind energy and to utilize decentralized generation to a maximum, Energinet.dk joined forces with energynautics and Spirae in order to develop an innovative network management technology. Goal of this Cell Controller Pilot Project (CCPP) is the creation of a system architecture that allows for a specific part of the distribution network (the Cell) to independently disconnect from the high-voltage network in case of a national emergency situation and to switch over to a controlled island operation. If switching over to controlled island operation fails, the cell is able to carry out a black-start itself and thus enter the state of a controlled island operation.
CCPP was not only initiated to ensure power supply during the very rare (but very serious) cases of a total blackout. It was also important to create a robust design that allows to incorporate new functions into the cell controller as sole software developments, without the necessity to replace hardware or to install new hardware.
The main idea behind this approach is that during an emergency it will be possible to quickly switch to island operation and that all functions of a normal technical operation can successfully run within this design.
To reach the goals of CCPP, the control software has to be able to carry out a number of functions for the pilot cell. These are briefly listed below:
- Online-monitoring of total load and production within the cell.
- Active power and reactive control of synchronous generators.
- Active power and reactive power control of wind farms and large wind turbines.
- Reactive power control by using capacitor banks of wind turbines and network.
- Voltage control through activating automatic voltage regulators (AVR) for synchronous generators.
- Frequency control through activating systems for speed control (SGS) for synchronous generators.
- Control of 60 kV breaker at 150/60 kV-transformers by the Cell Controller.
- Control of breaker of wind turbines and of load by the Cell Controller.
- Automatic fast switch to island operation of the entire 60 kV cell in case of serious network failures.
- Automatic fast load control in case of current fluctuations.
- Control of voltage, frequency and current during island operation.
- Synchronization of a cell back into parallel operation with the transmission network.
- Black-start support into the transmission network in case of a blackout.
Within this project, energynautics is responsible for carrying out power system simulations that test the operation of the cell controller prior to genuine field tests. After that, energynautics will compare the performance of the cell controller during the field tests to the simulated results. The first field tests in the Danish power system have been conducted in late 2008.
For further detailed descriptions of the project, see:
Cell Project (PDF | 2.95 MB)
Energinet.dk Pressrelease Cell Project (2008)
Energinet.dk Pressrelease Cell-Projekt (2010)
Publications Cell-Projekt (Date: 2011, PDF | 262 kB)
Energinet.dk Final Report