We are currently undergoing a major digital transformation in almost all processes of an electricity distribution company. CPFL (www.cpfl.com.br), one of the largest companies in the sector of energy in Brazil, seeks digitalization in all its operational processes, aiming at gains such as cost reduction and increase in the quality and productivity of services.
In line with this corporate strategy, the CPFL group’s Smart Grids engineering management seeks digital technological solutions with the same purpose in its projects. We understand that the complete digitalization of a substation involves the application of the Process Bus (IEC 61850-9-2) for the Substation Protection and Control System (SPCS). The implementation of the Process Bus goes far beyond the economics of removing copper cables from substation ducts. It enables a new horizon of opportunities that a digitalization of signals can offer, such as the implementation of the automation of SPCS operational tests. Substations fully digital could require weeks to test all of its functions, i.e, relay testing is expensive and intelligent choices regarding what we test and how the test must be made. The purpose of this paper is to propose the use of real Real-Time Digital Simulators (RTS), capable of publishing and subscribing GOOSE and Sample Values messages on the Process Bus, to perform operational tests in SPCS. In other words, the idea is present all the benefits achieved when RTS is applied for relay testing in field and not in laboratory environment only.
Historic:
Currently, factory acceptance tests (FAT) are carried out using analog signal injection equipment (secondary current and voltage), one bay at time. It is a very slow and laborious process as they involve the connection and disconnection of several copper cables in the panels, still in the factory. It is also worth noting that because bay-by-bay tests are performed, it is often not possible to evaluate the dynamic behavior of the other bays in the event of a real disturbance due to the lack of modeling of their components and interconnections.
Requirements:
To carry out these tests through the Process Bus, it will be necessary a RTS portable and robust, in order to facilitate its transport for carrying out tests in the factories, where the SPCS panels are assembled, and in the substations, where commissioning, maintenance and troubleshooting are performed. The simulator must also be able to be synchronized by a GPS via PTP (Precision Time Protocol) or similar protocol, publish and subscribe GOOSE and SV messages. The substation modeling capacity will facilitate the execution of operational tests, as well as the SCD file import, as defined by the IEC 61850 standard, arising from the SPCS configuration.
Expected results:
The implementation of the Process Bus in the SPCS will allow the use of digital tools for the injection of current, voltage and binary signals from all the bays of the substation, available on the same bus, without the need to connect any copper cables and power amplifiers.
This facility will enable the automatic generation of sequential and standardized operational tests, aiming at increasing their quality (precision and repeatability) and faster performance, compared to the technique currently used with analog equipment.
In addition, it will be possible to carry out unprecedented tests such as the verification of the dynamic behavior (permanent and transient phenomena) for the entire substation with voltage, frequency and current values, due to the application of the modeling of all electrical equivalents that make up the substation and the power system.