Software Development Of Integrated Protection Device In Smart Substation Based On Blackfin

At present, the layout of the devices in smart substation is hierarchical distribution according to difference of functions. This system architecture is object-oriented. And functions such as protection, control, monitoring, measurement and other functions are achieved by different independent devices. The advantage of this architecture is its high reliability. In other words, any system device failure will only affect itself or in part, will not impact the operation of the whole substation. And such a distributed system has good scalability and openness, which facilitates the expansion and upgrade of the system functionality. However, the available data source is generally limited to a single point or a bay in a distributed substation. So it’s difficult to make judgments and processing from the system point of view. Moreover, this limitation maybe causes the device to make a Non-optimal even wrong judgment, thus affecting the stability of the substation automation system and the development of substation automation technology.With the smart substations going deep into digital and intelligent, uniform collection and sharing of data becomes possible. So the Shortcomings of traditional integrated protection such as expansion difficulty caused by the secondary cable connection, front-end processor’s information "bottleneck" caused by the processing speed, will not exits. Integrated protection can identify the fault status accurately based on global data, and thus can achieve optimal protection functions.This thesis discusses the development of the integrated protection devices in smart substation as follows from the embedded development point of view.The application of Embedded multi-tasking operating system not only ensures the real-time and reliability of the device but also reduces the difficulty of the device function development greatly. The scalability of function is increased and the difficulty of function transplant in different software and hardware platforms is reduced. So the development cycle of device could be shortened and cost could be reduced.The monitoring function of switch status is usually achieved by scanning the switching value in timed interrupt or timing task. However this doesn’t meet the requirement of centralized protection considering response time, number of monitored switching value, accuracy of the time scale and so on. This thesis proposes a novel design of the monitoring function of switch status based on an embedded real-time multi-tasking operating system μC/OS-Ⅱ.It takes advantage of embedded real-time multi-tasking operating system’s functions, such as scheduling, message queues, and optimizes the allocation of resources and the management of switch data. The monitoring function including the debounce of switching value, SOE records and other related functions are implemented. Tests show that the reliability of debounce is improved and the response time is reduced. Besides, the performance of this design could be further improved and its functions could be more abundant. It provides a reference on switching value processing in centralized protection.Aiming at the Functional requirement of fault recording in smart substation, this thesis proposes a design of fault recording function based on embedded real-time multitasking operating system μC/OS-Ⅱ. It uses new methods of embedded development, such as embedded operating system, embedded state machine theory and takes advantage of functions of embedded operating system, such as multi-task scheduling, message queues. By doing this, not only the fault recording function is achieved but also the difficulty of programming is reduced and the reliability and portability of program is enhanced. This design has been applied in an integrated protection and control device and its performance is good. With more other functions such as network recording and analysis, state estimation be integrated, it will better meet the requirement of smart substation.