摘要:
A method and system are provided for operation of substations in which protection, control and measurement devices (e.g., Intelligent Electronic Devices (IEDs)) exchange operational data over a data network, for example, according to IEC standard 61850. During maintenance, commissioning and fault situations, when one or several IEDs are inoperable, the data that these IEDs would have produced is substituted to ensure availability of the substation. To this effect, a dedicated substitute device is permanently installed that can take the role of any IED, and that is automatically configured out of a standard configuration description (SCD) file that describes the SA system.
摘要:
Protection, measurement and control IEDs in a substation compute if switches they control may be operated safely, according to interlocking rules or physical principles as well as the dynamic topology of the substation. The IEDs have access to the substation electrical topology, to real-time information generated by other IEDs, and to the rules for interlocking. A standardized Substation Configuration Description (SCD) of the substation for which a Substation Automation system is intended, and a standardized description of the implemented device functions or capabilities of an individual IED are utilized. The substation topology is available from SCD file, real time information about the position of switches and line voltage/current can be obtained via an appropriate protocol, and the interlocking rules are available in script form. These features apply both to simulated and real devices, and increase system testing possibilities by supporting an efficient configuration of a simulation.
摘要:
The disclosure is concerned with the testing of system level functionality involving several Protection, Control and Measurement (PCM) Intelligent Electronic Devices (IEDs) of a Substation Automation (SA) system for IEC 61850 compliant substations. An extensive testing of all conceivable control or protection functions/applications of an extended SA system comprising a large number of IEDs with a multitude of configurations is facilitated by simulating at least one of the IEDs in a testing device. Hence, only a limited number of IEDs are physically present as individual devices in a test environment, the behaviour of at least one further IED being simulated by a dedicated testing device with appropriate data processing means. The testing device sends network messages indicative of the behaviour of the simulated IED according to its communication and device configuration over a substation communication network to the physically present IED to be tested. The proper working of the configured IED functions, i.e. the expected correct action as triggered by the testing device, are then verified.
摘要:
Exemplary embodiments increase reliability of communication over a non-deterministic communication channel, in electric power systems. A communication channel is monitored based on regular network traffic, by evaluating messages or data packets carrying real-time operational data as a payload. A permanent determination of a channel quality, including appropriate alarming in case the channel quality is found insufficient, is based on an evaluation, at a receiving node, of data packets continually transmitted by a sending node. These continually or repeatedly transmitted data packets can include identical payloads reflecting current states rather than state changes as operational data.
摘要:
In order to reduce the down time of a computer (1, 4-8) caused by a fault or interrupt in the program run, program recovery points are provided which are time-dependent or can be preset in the main program of a useful program, and when these recovery points are reached, the computer status is stored in at least one fault-tolerant archival memory (5, 6). The computer status includes the status of the variables of a useful program being executed, the register status of the processor (1) and the register status of the input/output devices of the computer. During execution of the useful program, at least a part of the current computer status is stored in a main memory (4) and copied into an archival memory (6) when a program recovery point is reached. By using a small, fast cache memory (7) between the processor (1) and the main memory (4), the write cycles in the archival memories (5, 6) may be reduced since a variable is replaced in the main memory (4) only when it is displaced from the cache memory by a variable which may have been updated several times. A further improvement is achieved by using an associative stack (8) on the bus (2, 3) as the main (4) and the two archival memories (5, 6). All modifications in the main memory (4) are simultaneously entered into the stack (8) and into an archival memory (5) without involving the processor (1). In the stack (8), address data pairs are entered in the order of occurrence, a character recording the respective state of the stack and allocating locations to new address/data pairs. At the recovery point, only updated data need to be transferred into the archival memory. The main memory (4) can be integrated into an archival memory having a read/write memory area and a fault-tolerant tributary memory area. A cascaded memory or a virtual memory of the computer can also be used for saving the computer status.
摘要:
Specimen programs (S1) of a specimen object (1) can be tested by means of an observation tool (2), and the duration of program routines registered and evaluated. In order to achieve a better testing depth, the observation tool (2) is additionally supplied with at least one measurement and/or process signal from at least one simulated process (P′) from a real time simulator (4) or from a process (P) of a plant (3). At least one signal is transmitted from the simulated process (P′) to the observation tool (2), it being possible for this signal to be generated by the process (P) or (P′), and said signal triggering a test by the observation tool (2).
摘要:
In such a multiprocessor, in which the common memory (M) or one of the cache memories (C1, C2) can be owner of a variable determined by its address and in which it is always only the owner of a variable which delivers it to the bus (1) following a read request, the concept of ownership is further developed by the present invention with respect to implementing it with standard buses which, per se, are not intended for this purpose, and with respect to the greatest possible efficiency.
摘要:
The present disclosure provides a secure one-step IEEE 1588 clock using either a symmetric or asymmetric protection scheme. Clocks of mission-critical or highly-available devices in industrial automation systems connected to a communication network are synchronized by sending, by a master clock, a synchronization message, e.g., a single message of the one-step-clock type according to IEEE 1588, including a time stamp, and by receiving and evaluating, by a slave clock, the synchronization message. A synchronization component or module of the master clock prepares, or composes, prior to a projected send time, a synchronization message including a time stamp of the projected send time, and secures the synchronization message in advance of the projected send time. Securing the synchronization message occurs by suitable cryptographic means allowing for authentication of the time stamp at a receiving slave clock. At the projected send time, the secured synchronization message is transmitted.
摘要:
The present disclosure relates to highly available communication networks, e.g., for industrial or utility applications such as substation automation. The devices are connected to two redundant lines through two independent transceivers and bus controllers, i.e. the physical layer and the link layer of the corresponding protocol stack is duplicated. For seamless operation, a sender sends frames simultaneously over both lines and a receiver accepts whichever frame of a pair comes first and ignores the late frame. An exemplary method is disclosed for discarding duplicate frames at the link layer without considering the higher protocol layers, based on a counter inserted in the frame and an algorithm for rejection, with a corresponding means to detect which frames operate according to the redundancy protocol.
摘要:
Exemplary embodiments are directed to a network coupling device connected over a respective first and second port in a communication network with a ring topology operating with full duplex links. When sending information, the coupling device inserts two duplicate frames in the ring, one over each of its ports. The frames containing information that identifies these two frames as a pair of duplicates of the same frame. Each similar device in the ring includes a Switching Element that receives a frame from one port and forwards the frame to the other port without modification. The Switching Element discards a frame that was originally sent by that same node, discards a frame that it already forwarded in that direction, and/or discards a frame that it cannot recognize as being a member of a pair. A further similar device on the ring is able to receive the two duplicate frames and pass the earlier received frames of a pair to the application, while discarding the later, received frames based on the identification within the frames.