Creating a test environment for smart switching and protection devices, where faults in electricity grid can be simulated and remediation strategies can be verified.
By using simulation system based on NI CompactRIO hardware and NI LabVIEW software, signals corresponding to short circuits in different locations of the grid can be generated and fed to the protection devices. Devices react to faults as they would in a real power distribution system, allowing engineer to test and compare system design options.
Diego Pagnoncelli - ABB
Enrico Againi - ABB
Lorenzo Fontana - ABB
Luca Milani - ABB
The ABB Smart Lab, located in Dalmine, Italy, is a facility dedicated to the experimentation, research and demonstration of innovative technologies. One of the main focus areas is power distribution.
At the core of the Smart Lab there is a simulator that can generate signals to reproduce, currents and voltages as measured by the sensors of protection devices in different situations. In particular, faults in a Medium Voltage and Low Voltage distribution systems are studied, in order to verify how fault protection devices (relays and circuit breakers) would react in such situation.
In the laboratory there are 4 medium voltage switchboards that represent the nodes of the distribution network and, in each of them, the relays REF615 corresponding to the input and output lines of each node. In total, the system has 28 relays divided as follows:
- 6 in switchboard 1
- 4 in switchboard 2
- 9 in switchboard 3 and 4
Each relay requires input to its sensors 3 voltage signals and 3 current signals, so a total of 168 signals for the entire network are generated by the CompactRIO system. The waveforms of currents and voltages, different for each fault condition, have been recreated in the form of files using a simulation program and can then be applied to real devices using the LabVIEW software.
Simulation involves the following steps:
1. Using the LabVIEW user interface, the operator chooses the location on the network where the fault occurs.
2. Relevant files are downloaded and transferred to the FPGAs of the CompactRIO units.
3. Once the file transfer is complete (signalled by a green LED on the interface), the operator starts the simulation by pressing the trigger button.
The system, from the hardware point of view, is composed of:
- 2 chassis cRIO 9031 (4 slots each) for switchboards 1 and 2
- 2 chassis cRIO 9036 (8 slots each) for switchboards 3 and 4
Each chassis is equipped with modules for analog generation NI 9264 (16 channels) to allow you to send the 6 analog signals to relay the REF615. In addition, NI 9421 digital inputs, and NI 9472 digital outputs are used for auxiliary functions. The CompactRIO modules are used to generate voltage and current signals that mimic network behavior. Since a considerable number of protection relays are involved,a modular architecture has proven especially suitable. To the purpose of ensuring a high-quality simulation, it is very important that voltage and current signals are precisely synchronized with each other: one of the most interesting aspects of the design implemented in the lab is the generation of sets of synchronized transient voltages and currents.
The distribution of modules is as follows. The LabVIEW program running on the Host implements the user interface used for choosing the fault event and display relevant waveforms at specific points of the network. Communication between Host and RT controller is via TCP / IP and uses METADATA for code optimization.
The simulation system provides a complete test environment for coordination between protection systems without the need of a real power system with high voltages and currents, which would be very expensive and more dangerous for operators. Quality of simulation is satisfactory.