Abb Research Ltd.

Abb Technology Ag

Hubert Kirrmann

Jean-Charles Albert Tournier

Wolfgang Wimmer

Michael Obrist

Dacfey Dzung

Hermann Spiess

Claus Vetter

Peter Terwiesch

Stefan Ramseier

Martin Israel

Tetsuji Maeda

Allen Notter

Peter Mueri

Jean-Charles Tournier

Cagri ÖNal

Mats Hansson

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.

Secure clock synchronization

A network management agent, device or module determine the network topology of a communication network based on at least one neighbor network or end device identity and corresponding network link communication delay collected from, determined by, and stored in a Management Information Base of, at least one first network device of the communication network. Neighbor identities and communication delays are determined according to the IEEE 1588 standard.

Determining the network topology of a communication network

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.

Operating a substation automation system

Exemplary embodiments are directed to a communication network interconnecting a plurality of synchronized nodes, where regular frames including time-critical data are transmitted periodically or cyclically, and sporadic frames are transmitted non-periodically or occasionally. For example, each node can transmit a regular frame at the beginning of a transmission period common to, and synchronized among, all nodes. Another node then receives regular frames from its first neighboring node, and forwards the frames within the same transmission period and with the shortest delay, to a second neighboring node. Furthermore, each node actively delays transmission of any sporadic frame, whether originating from an application hosted by the node itself or whether received from a neighboring node, until forwarding of all received regular frames is completed.

Frame transmission and communication network

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.

Communication method and system

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.

Reception of redundant and non-redundant frames

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.

Ring coupling nodes for high availability networks

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.

System level testing for substation automation systems

Specimen programs (S,) of a specimen object (,) can be tested by means of an observation tool (,), and the duration of program routines registered and evaluated. In order to achieve a better testing depth, the observation tool (,) is additionally supplied with at least one measurement and/or process signal from at least one simulated process (P&prime;) from a real time simulator (,) or from a process (P) of a plant (,). At least one signal is transmitted from the simulated process (P&prime;) to the observation tool (,), it being possible for this signal to be generated by the process (P) or (P&prime;), and said signal triggering a test by the observation tool (,).

Growing community of inventors

Dättwil, Switzerland

Hubert Kirrmann