Smart grids name electricity networks that use digital technology to coordinate requirements of all electricity stakeholders – generators, system operators, end users and other aggregators – in a such way that it can optimize performance with a good power quality level and a high stability. Smart grids are evolving towards a much more distributed architecture with Distributed Energy Resources (DERs). Thus, it is necessary to establish new protection systems. Standards such as IEC 61850 can provide new ways to control DER efficiently.
IEC 61850 can provide several benefits to transmission and distribution networks and even in end-user installations where an important distribution network is present. Some of these advantages are the distributed automation between all protection and control elements of the system, offering multiple automation possibilities, the scalability of the installation and the reduction of installation costs.
This distributed automation is due to the use of one of IEC61850’s services, the GOOSE messaging. GOOSE messaging can provide direct communication from one IED (Intelligent Electronic Device) to the rest. Conceptually the GOOSE service has been implemented in order to substitute the traditional signal wiring in the control systems providing additional several advantages:
- Traditional wires among IEDs are replaced by only communication architecture.
- The GOOSE message can carry more information that a simple cable.
- All connections between IEDs are established for future expansions.
- Reduced cost in front traditional wiring.
- Continuous supervision of GOOSE messages in front of traditional wiring.
GOOSE messaging opens a new world of possibilities to develop in electrical network systems for any kind of substation automation, but also in any kind of industrial process system where it is necessary to conduct actions such as load shedding, automatic transfers, LV loads’ management, etc.
GOOSE messages have a high priority in front of other kind of communication and its emission time is in the range of 2 ms to 4 ms, using its publisher-subscriber mechanism. As Ethernet network is non-deterministic, nowadays using redundancy network protocols as HSR and PRP with zero-second convergence time the GOOSE message can reach the deterministic property. The application of these protocol offers robustness to the network.
One of the important points in an electrical system for an end-user substation is to have the IEDs ready with the appropriate settings according to current scenario. For instance, if in an electric system is disconnected from the network and activates its auxiliary generation, the settings of the system have to change to this new situation. For every auxiliary generation source that connects to the system, the settings will vary. In traditional installations this kind of adaptive configuration is done by a control system which analyzes the situation and modifies the settings in each IED. The GOOSE service provides a fast change among IEDs without having to use the control system: the intelligence is distributed in the system. Critical operations like this can be done by means of this technology in order to get a fast and direct answer.
As mentioned the GOOSE service can provide several benefits to optimize the electrical distribution in an end-user installation. This table shows a comparison between traditional wiring and use of IEC 61850 and its benefits.
Table. Comparative analysis between IEC 61850 and traditional wiring.
For more information about adaptive protection and benefits of IEC 61850, download the publication “Using IEC 61850 GOOSE Service for Adaptive ANSI 67/67N Protection in Ring Main Systems with Distributed Energy Resources” – written by Angel Silos, Aleix Señis (both from Schneider Electric) with Ramon Martin de Pozuelo and Agustin Zaballos (both from La Salle – Ramon Llull University). This paper analyzes the potential usage and beneﬁts of ANSI 67/67N protection in combination with Generic Object Oriented Substation Event (GOOSE) communication service, from the IEC 61850 standard for providing adaptive network protection, specifying the conﬁguration and implementation, and achieving the obtained results.