Coordination of Different Generator Sets
Generator sets typically have their own primary controllers. If several of them operate jointly in an island grid, they need to be coordinated. Generation control ensures the most reliable power generation possible in industry grids containing several generator sets both connected to an external power utility and in island mode.
Ensuring Grid Stability
Generation control establishes evenly balanced active power that enables power demand from an external grid to be set, to keep within a maximum purchasing limit from the external grid, or to stabilize the frequency in the islanded grid. It can, however, also establish evenly balanced reactive power in order to maintain a desired power factor angle at the tie-line to an external grid or to stabilize the rated voltage of the busbars in island mode. Generation control also calculates the spinning reserve in order to ensure that there is always sufficient control capacity available.
Efficient and Convenient
Generation control is totally integrated in substation automation and runs on a central computer, with optional redundancy available. As a result, there is no need for additional devices or inputs/outputs. In addition, the same user interface is used for control and monitoring as well as for power management. This provides a very transparent means of displaying numerous parameters, for example, power flows and reserves, operating modes, individual generator sets, and entire grid areas.
The process i.e., condition and measured value acquisition as well as the output of commands and setpoint values is interfaced via field and/or telecontrol devices. These are linked to the plant control center via high-speed communication. This distributed architecture enables the connection to be flexibly adapted to the primary controllers. Important machine data and setpoints are exchanged via serial and parallel interfaces.
This concept provides an efficient and reliable system solution for new plants as well as for the refurbishment of existing plants.
Power-based load shedding continuously calculates the necessary reactions to critical scenarios that could occur and is therefore prepared for all eventualities at all times. This predictive approach is used for fast load shedding as well as for blocking of large loads.
Fast Power-Based Load Shedding
GCritical events like a disconnection from the external power utility grid or the failure of a generator in island mode require the fastest load shedding possible in order to limit the resulting drop in power frequency and prevent triggering of the under frequency protection. The system only sheds as much load as necessary for restoring the rated frequency.
Dynamic Power-Based Load Shedding
In stable island mode, loads change as needed by the industry process. These variations are balanced by the primary control of the on-site turbines. As the power requirement increases, the spinning reserve decreases, reducing the capability for starting big loads. Dynamic load shedding monitors the spinning reserve for a defined limit value. While it is permissible to exceed the limit for short periods, load is shed if these periods last for longer in order to restore the required reserve. In addition, in island mode large consumers are monitored while in the idle state. If the spinning reserve falls below these starting power level, a signal inhibits the start and so prevents grid overload.
Frequency-Based Load Shedding
This function is available both as an independent main function for ordinary applications and as a reserve function for fast power-based load shedding. It monitors when the frequency drops below given thresholds and sheds predefined loads as required, independent of the control system. It can function in the event of multiple faults in the grid, and also sheds loads reliably even when the central unit is disconnected.
Control & Monitoring as well as archiving and evaluation of non operational data are important aspects of a modern Substation Automation System.
All energy suppliers whether they provide electricity, natural gas, water, or district heating face ever greater and more complex demands as they implement new energy mixes. Our solutions are scalable system for a broad range of applications and can be used from an integrated energy system for refineries, industrial zones, power plants, airports, utilities, underground transportation systems, iron and steel plants etc. to monitor for smart grid applications. The architecture is completely consistent from the on-site controls to the redundant multi-hierarchic control system. All sort of communication protocols can be used to ensure highly flexible HMI designs with third party equipments for complex systems.
REMOTE TERMINAL UNIT (RTU)
A high level of functionality and flexibility are the foundation for a successful automation system. Naturally, that also includes comprehensive options for telecontrol, communication and for connecting peripheral equipment.
All sophisticated communication protocol standards are applicable on RTU Systems, such as IEC 60870-5-101, IEC 60870-5-103, IEC 60870-5-104, IEC61850, Modbus RTU, Modbus TCP/IP, DNP3, Profibus DP, etc. Our solutions for substation automation comply with IEC 61850. This standard represents a major step toward grid intelligence, because it meets the high communication requirements in terms of data volume, speed, etc. Additional benefits include easy integration of third-party devices and maximum viability for the future thanks to reusable engineering data. Intelligent applications can also be implemented through IEC 61850.
For substation automation, we offer you preconfigured (and therefore highly cost-effective) system solutions for many typical applications. We also develop individual solutions to meet specific customer requirements. We supply all the secondary equipment in transmission and distribution networks for new installations, expansions, and modernizations. Our products and solutions feature scalable quantity structures, while offering a variety of interfaces and efficient operation on all levels.