Two-way data transmission between SCADA and DMS - a support system interface

摘要

One of the most interesting area in the domain of distribution automation is the development of a distribution management system (DMS). The efficient use of the DMS calls for flexible access to the data of other computer systems (i.e. the need of open architecture and well-defined data interfaces). The paper focuses on the data transmission between the DMS and a supervisory control and data acquisition (SCADA) system. The paper describes the DMS integrating the distribution automation and computer systems used by electricity distribution utilities in their network operation. The DMS includes many advanced applications useful for the control center operator. Such applications are, for example, topology supervision, real-time network monitoring and optimization based on sophisticated network calculations, short term load forecasting, switching planning, and fault management. The DMS introduced has been developed jointly by the universities, software companies and distribution utilities. The commercial product, called Open++ Opera, is now been revised by ABB Transmit Oy. At present the DMS is in everyday use in several companies. The focus of the paper is on the two-way data transmission between the DMS and SCADA system. The DMS maintains the state of distribution process by collecting information on the process through the SCADA. The DMS and the SCADA have been connected using application program interfaces (API) based on a socket and TCP/IP data transmission protocols. An application which works as a server in the support system interface (SSI) has been connected as part of the SCADA. The client application is part of the DMS. Once the connection has been formed, the client and the server use the defined messages of the SSI for data transmission. The connection is two-way; the switching, measurement and event data is transferred cyclic and/or event based from the SCADA to the DMS, and the switching commands of remote controlled disconnectors and circuit-breakers can be send from the DMS to the SCADA. The paper points out how the SSI and SCADA information are used in different DMS functions. The DMS as a part of a substation control system is also discussed. As a practical installation the implementation in a pilot company during the development work is presented finally. The experiences on the everyday use of the DMS have been very promising gained during the past few years.