506 Energy Sector t Power Guide t Edition 7.0 Glossary

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Siemens Energy Sector t Power Engineering Guide t Edition 7.0 507 Glossary

A Circuit-breaker A mechanical switching device, capable of making, carrying and breaking currents under Air circuit-breaker A –> circuit-breaker in which the contacts open normal circuit conditions and also making, and close in air at atmospheric pressure. carrying for a specified time and breaking Air-insulated High voltage substation where all live parts are currents under specified abnormal circuit outdoor switchyards insulated by air and are not covered. AIS are conditions such as those of short-circuit. of open design (AIS) always set up in a fenced area with access for Common The Common Information Model (CIM) is an authorized personal only. information model open standard that defines how managed Ambient Temperature (measured under specific (CIM) elements in an IT environment are represented temperature conditions) of the air surrounding an item of as a common set of objects and relationships electrical equipment. The ambient temperature between them. This is intended to allow affects heat dissipation, which can make it consistent management of these managed necessary to reduce the –> rated current. elements, independent of their manufacturer or provider. Auto-reclosing (of a The operating sequence of a mechanical mechanical switching device whereby, following its Contactor Load breaking device with a limited short- switching device) opening, it closes automatically after a circuit making or breaking capacity, used for predetermined time. high switching rates. Automatic multiple An automatic reclosing repeated two or three Continuous Function A Siemens engineering tool that offers shot reclosing times (usually not more) if it is not successful. Chart (CFC) graphical interconnection and parameterization of off-the-shelf or user-defined function blocks B to solve sophisticated continuous control applications –> SFC. Back-up protection Interaction of two carefully matched overcurrent protective devices connected in Current limiting Ability of an overcurrent protective device ( series at points where, in the event of a fault, a or circuit-breaker) to reduce the peak current in single device is not capable of switching the a circuit beyond the value of the peak short- prospective short-circuit current. If a circuit current expected on the basis of the correspondingly high short-circuit current circuit constants (R, L), by opening and clearing occurs, the back-up overcurrent protective the fault in a sub-cycle time frame. device relieves the next downstream Current-limiting A circuit-breaker with a break-time short overcurrent protective device, thus preventing circuit-breaker enough to prevent the short-circuit current it from being overloaded. reaching its otherwise attainable peak value Blackout Complete . Current transducer Transducer used for the measurement of an Breaking operation Interruption of an electric circuit as a result of . the contact members of a switching device Current Type of instrument transformer designed to being opened. (CT) provide a current in its secondary winding Breaking capacity Highest current a switching device is capable of proportional to the alternating current flowing breaking under specific conditions. in its primary. CTs facilitate the safe measurement of large currents, often in the A low impedance conductor, to which several presence of high voltages. The current electric circuits can be connected separately. transformer safely isolates measurement and Busbar trunking Extended enclosed , equipped with control circuitry from the high voltages system outgoing points for supplying machines and typically present on the circuit being measured. other loads with power via variable tap-off D units. DCF77 A longwave time signal and standard-frequency Bushing Device that enables one or several conductors radio station. The transmitted data repeats to pass through a partition such as a wall or a each minute the current date and time, a leap tank and insulate the conductors from it. second warning bit, a summer time bit, a C primary/backup transmitter identification bit, and several parity bits. The callsign DCF77 Capacitor voltage A –> voltage transformer comprising a stands for D=Deutschland (Germany), C=long transformer (CVT) capacitor divider unit and an electromagnetic wave signal, F=Frankfurt, 77=frequency: unit designed and interconnected so that the 77.5 kHz. secondary voltage of the electromagnetic unit is substantially proportional to the primary Dead tank circuit- A –> circuit-breaker with interrupters in an voltage, and differs in phase from it by an angle breaker earthed metal tank. which is approximately zero for an appropriate strength Capability of an electrical component to direction of the connections. withstand all voltages with a specific time CAPEX Capital expenditures of an enterprise for fixed sequence up to the magnitude of the assets, e.g. means of production, buildings etc. corresponding withstand voltages. These can 11 –> OPEX. be operating voltages or higher-frequency voltages caused by switching operations, earth Continuous –> Kaizen faults (internal overvoltages) or lightning improvement strikes (external overvoltages). process (CIP)

508 Siemens Energy Sector t Power Engineering Guide t Edition 7.0 Glossary

Demilitarized zone A subnetwork between an organization’s LAN G (DMZ) and an external network, usually the internet. The hosts in the DMZ contain and provide all Gas-insulated Indoor and outdoor of compact external services of an organization such as switchgear (GIS) design and small dimensions for substations up e-mail or web server, but are not allowed to to 550 kV to be installed in urban or industrial connect directly to the internal LAN. loadcenters. All components are housed in earthed metal enclosures filled with sulfur Mechanical switching device which, in the hexafluoride (SF ) gas for insulation. (isolator) open position, disconnects all the poles of an 6 electric circuit. are used for no- Gas-insulated Transmission lines composed of pipes that load closing and opening operations, e. g. to transmission line house conductors in highly insulative sulfur

isolate downstream devices so they can be (GIL) hexafluoride (SF6) gas, which have high load- worked on. transfer capacity. units, such as PV panels, wind Generic Interface A set of common services used for enterprise generation units turbines, or units, which are Definition integration in the utility industry, defined in IEC connected to the LV or MV distribution standard IEC 61970. network. GPRS A packet oriented mobile data service available E to users of –> GSM. Grid-connected A photovoltaic system in which the Ear and mouth A technology in voice over IP (VoIP) that uses a photovoltaic system photovoltaic array acts like a central generating (E&M) traditional telephone handset with an plant, supplying power to the grid. earphone (or earpiece) for listening to incoming audio and a microphone (or Grid power flow A concept in system technology within the –> mouthpiece) for transmitting audio. Calls using controller (GPFC) FACTS family of devices that provides an an E&M interface can be made from, received economic solution for the purpose of power from, or disconnected by a private branch transmission between two or more adjacent AC exchange (PBX) as well as from a VoIP-capable systems. The AC systems can be either computer. The term ear and mouth interface is synchronous or nonsynchronous. The most sometimes used as a synonym for a telephone proper power rating is between 10 MW and handset itself, or for a headset-and-microphone 300 MW, although higher ratings are also combination that allows hands-free operation. achievable. Earth fault Occurrence of an accidental conductive path GSM A worldwide standard for mobile phones. between a live conductor and the earth. H Earthing Mechanical switching device for earthing parts of an electric circuit, capable of withstanding Harmonics The sinusoidal (harmonic) oscillations in the for a specified duration electric currents under Fourier analysis of non-sinusoidal, periodic abnormal conditions such as those of short- oscillations that oscillate at a frequency which circuit, but not required to carry electric current is an integer multiple of the fundamental (= under normal conditions of the electric circuit. system) frequency. The amplitudes of harmonics are considerably smaller than the ECR A zero boron glass that is free of added fundamental frequency. fluorides. It conforms to ASTM D578-1999 specification for E glass. It combines the High voltage In general a set of voltage levels in excess of –> electrical and mechanical properties of E glass low voltage (< 1 kV). In a more restrictive sense with superior inherent corrosion resistance. HV is used for voltage levels typically used for ECR glass fiber is an electrical grade corrosion bulk transmission of (> 60 kV). resistant glass fiber. HTTP/HTTPS The hypertext transfer protocol/hypertext F transfer protocol secure is a communications protocol for the transfer of information on the Feeder An electric line originating at a main substation intranet and the World Wide Web; HTTPS is and supplying one or more secondary widely used for security-sensitive substations. communication.

Flexible AC A power electronic based system and other I transmission system static equipment that provide control of one or (FACTS) more AC transmission system parameters to Incoming feeder In a substation a feeder bay which is normally enhance controllability and increase power used to receive power from the system. transfer capability. Instrument Transform high currents and voltages into small File transfer protocol Transfer protocol for exchanging files over any transformer current or voltage values for measuring or (FTP) –> TCP/IP based network. protection purposes. Fuse A protective device that by the fusing of one or Inter-Control Center The Inter-Control Center Communications more of its specially designed and proportioned Communication Protocol (ICCP or IEC 60870-6/TASE.2) is being components, opens the circuit in which it is Protocol (ICCP) specified by utility organizations throughout 11 inserted by breaking the current when this the world to provide data exchange over wide exceeds a given value for a particular period of area networks (WANs) between utility control time. The fuse comprises all the parts that form centers, utilities, power pools, regional control the complete device. centers, and non-utility generators.

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Insulated gate A three-terminal power semiconductor device, O bipolar transistor noted for high efficiency and fast switching. (IGBT) OASIS System for reserving transmission capacities in the US power transmission networks. IRIG timecodes Family of standardized timecodes used by the U.S. Government and the private industry for ODBC Standard database access method for using the correlation of data and time. database management systems. IT system Power supply system that does not provide a OLE Object Linking and Embedding (OLE) is direct connection between live conductors and a technology that allows embedding and earthed parts; exposed conductive parts are linking to documents and other objects earthed. developed by Microsoft.

J OPC A set of connectivity standards for industrial automation from the OPC Foundation, which K offers interoperability between gauges, databases, programmable logic controllers Kaizen A Japanese philosophy that focuses on (PLCs), distributed control systems (DCSs) and continuous improvement throughout all remote terminal units (RTUs). aspects of life, which was first implemented in several Japanese businesses as a management Operating voltage The value of the voltage under normal strategy after World War II, adopted to (in a system) conditions, at a given instant and a given point businesses throughout the world also as of the system. Continuous Improvement Process (CIP). OPEX On-going cost for running a product, business, Konnex (KNX) Standardized bus system for home and building or system. applications according to EN 50090 and ISO/IEC OSCOP® P A PC program for retrieving and processing of 14543, comprising switching, signaling, records made with the SIMEAS R digital fault controlling, monitoring, and indicating and power quality recorder, the SIMEAS Q functions in the electrical installation. power quality recorder, or with numerical protection relays using the IEC 60870-5-103 L protocol. LCAS Link Capacity Adjustment Scheme or LCAS is a OSI A layered, abstract description for method to dynamically increase or decrease the communications and computer network bandwidth of virtual concatenated containers protocol design. to effectively transfer asynchronous data streams over –> SDH. Outgoing feeder A feeder bay in a substation which is normally used to transmit power to the system. Live tank circuit- A –> circuit-breaker with interrupters in a tank breaker insulated from earth. Overcurrent Any current in an electric circuit that exceeds the –> rated current. Low voltage (LV) Set of voltage levels used for the distribution of energy up to 1,000 V AC, or 1,200 V DC. Overload Operating conditions in an electrically sound, fault-free electric circuit that give rise to an –> L-tripping Overload protection. overcurrent.

M P

Miniature circuit- Automatically-operated low-voltage switching PABX A telephone exchange that serves a particular breaker (MCB) device designed to protect an electrical circuit business or office, as opposed to one that a from overload or short-circuit. Also used to common carrier or telephone company manually connect or disconnect an electric operates for many businesses or for the general circuit at will. Rated current not more than public. 125 A. Pulse-code A digital representation of an analog signal Molded-case circuit- A circuit-breaker having a supporting housing modulation (PCM) where the magnitude of the signal is sampled breaker (MCCB) of molded insulating material forming an regularly at uniform intervals, then quantized integral part of the circuit-breaker. to a series of symbols in a numeric (usually Medium voltage Set of voltage levels lying between –> low binary) code. (MV) voltage (LV) and –> high voltage (HV). The PDH An international multiplexing standard. boundaries between HV and LV depend on local circumstances and history or common usage. PE conductor Conductor provided for purposes of safety, for The band 1kV to 52 kV is commonly accepted in example protection against electric shock. In an Europe. The term medium voltage is nor used electrical installation, the conductor identified in the U.K. nor in Australia. PE is normally also considered as protective earthing conductor. Metall oxide varistor A discrete electronic component that is (MOV) commonly used to divert excessive current to Phase-shifting A device for controlling the power flow through the ground and/or neutral lines. transformer specific lines in a complex power transmission 11 network. N (Photovoltaik) Peak Maximum “rated” output of a photovoltaic cell, Neutral conductor A conductor connected to the neutral point of a Watt module, or system. Typical rating conditions (N) system, which is suitable for transmitting are 1000 W/m2 of sunlight, 20 oC ambient air electrical energy. temperature and 1 m/s wind speed. N-tripping Neutral conductor protection. PEN (conductor) Combined –> PE and –> N conductor.

510 Siemens Energy Sector t Power Engineering Guide t Edition 7.0 Glossary

Power-line carrier A device for producing radio-frequency power Resistance Device for temperature detection based on the for transmission on power lines. temperatur device/ resistance change in a metal, with the detector (RTD) resistance rising more or less linearly with Potential A device required to provide accurate voltages temperature. transformer (PT) for meters used for billing industrial customers or utility companies. Remote terminal An electronic device to transmit data to a unit (RTU) distributed control system or a SCADA-system Python A dynamic object-oriented programming and to alter the state of connected objects language. based on control messages received from the Q system. S R Switch-disconnector A switch which, in the open position, satisfies Rated breaking Value of the short-circuit current a switching the isolating requirements specified for a capacity device is c apable of breaking at the rated disconnector. operating voltage, rated frequency and specified (or specified time Switch-disconnector- A switch-disconnector comprising a –> switch- constant). fuse (SDF) disconnector and (connected in series zo this) fusebases for insertign fuse-links. Rated breaking The load breaking current in normal operation. current SDH A multiplexing protocol for transferring multiple bit streams over the same optical fiber. Rated current The current that an electrical device can carry, under specified conditions, without resulting in Selectivity Combined operation of overcurrent protective overheating or mechanical overstress. devices connnected in series to provide graded disconnection. Rated insulation The –> dielectric strength from phase to earth, level between phases and across the open contact Series reactor A reactor intended for series connection in a gap, or across the isolating distance. The network, either for limiting the current under dielectric strength is verified by a lightning fault conditions or for load-sharing in parallel impulse withstand voltage test with the circuits. standard impulse wave of 1.2 / 50 s and a power-frequency withstand voltage test SFC A graphical programming language used for (50 Hz/1 min). PLCs. It is one of the five languages defined by IEC 61131-3 standard. The SFC standard is Rated peak The peak value of the major loop of the short- defined in IEC 848, “Preparation of function withstand current circuit current during a compensation process charts for control systems”. after the beginning of the current flow, which the device can carry in closed state. Short-circuit Connection of two or more points of an electrical circuit that are meant to be at Rated short-circuit The root-mean-square value of the breaking different voltages across a nebligible small breaking current current in case of short-circuit at the terminals resistance or impedance. of the switching device. Short-circuit current Overcurrent which flows through the –> short- Rated short-circuit The peak value of the making current in case of circuit which may result in thermal or making current short-circuit at the terminals of the switching mechanical overloading of the electrical device. equipment. Rated voltage The maximum voltage at which an electric Short-circuit The mechanical resistance of switching devices component can operate for extended periods strength to short-circuit stress, particularily of busbars in without undue degradation or safety hazard. switchgear stations and distrivution boards. Release (of a A device, mechanically connected to a Shunt release A release energized by a source of voltage. mechanical mechanical switching device, which releases switching device) the holding means and permits the opening or Shunt reactor A reactor intended for shunt connection in a the closing of the switching device. network to compensate for capacitive current. Residual current The sum of the instantaneous values of all Single-line diagram A simplified notation for representing a three- currents that flow through all the active (SLD) phase power system in which the polyphase conductors of an electrical system at one point. links are represented by their equivalent single line. Residual current A mechanical switching device designed to device (RCB) make, carry and break currents under normal Evolving intelligent power distribution network service conditions and to cause the opening of using communication, advanced sensors, and the contacts when the residual current attains a distributed computers to improve the given value under specified conditions. efficiency, reliability and safety of power delivery and use. It includes the possibility for Switchgear in distribution systems comprising demand side management, facilitating grid (RMU) of for switching power cable rings and connection of distributed generation power of switches in series with fuses for the (with photovoltaic arrays, small wind turbines, protection of distribution . micro hydro, or even combined heat power 11 generators in buildings), grid Rapid spanning tree Networking protocol according to IEEE 802.1w for distributed generation load balancing, and protocol (RSTP) to deactivate redundant paths in a local net or improved reliability against many different to activate them if required (e.g. in case of a component failure scenarios. failure of a switch, brigde etc.).

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SNCP A protection mechanism used in –> SDH Transient Very short duration increase in voltage, overvoltage between two or more conductors. Transient SNMP SNMP is used in network management systems overvoltages are mainly caused by the to monitor network-attached devices for secondary effects of lightning or by electrical conditions that warrant administrative switching events and may cause serious attention. It consists of a set of standards for damages to components of the electrical supply network management, including an Application network. Layer protocol, a database schema, and a set of data objects. Tripping current Current value at which a tripping element trips within a particular time. SOAP A protocol for exchanging –> XML-based messages over computer networks, normally TT system Power supply system; in the TT system one using –> HTTP/HTTPS. Formerly SOAP was a point is directly grounded, all exposed acronym for Simple Object Access Protocol, conductive parts are connected to grounding which was dropped with Version 1.2. electrodes which are separated from the system grounding. SONET Multiplexing protocol for transferring multiple bit streams over the same optical fiber. TTA Type-tested low voltage switchgear assembly. SQL Database computer language designed for the Type-tested LV Assembly of low-voltage controlgear and retrieval and management of data in relational controlgear and switchgear built and type-tested according to database management systems. switchgear assembly IEC 60439-1/EN 60439-1/DIN VDE 0660-500. (TTA) STM Synchronous Transport Module (STM), the basic unit of framing in –> SDH U

S-tripping Short-time delay short-circuit protection. UMTS Universal Mobile Telecommunications System; Substation A part of an electrical system, confined to a third-generation cell phone standard that given area, mainly including ends of allows significantly higher data transfer rates transmission or distribution lines, electrical than GSM. switchgear and controlgear, buildings and USB Serial bus standard to interface devices. transformers. A substation generally includes safety or control devices (for example V protection). A cluster of distributed generation installations Surge arrester A device designed to protect the electrical (VPP) which are collectively run by a central control apparatus from high transient overvoltages entity. The concerted operational mode shall caused by lightning strikes or switching result in an extra benefit as to deliver peak load operations. electricity or balancing power at short notice. Switch/switching Device for making or breaking a current in an Visual Basic for An event-driven programming language and device electric circuit. Applications (VBA) associated integrated development Switch-disconnector A switch which, in the open position, satisfies environment (IDE) which is built into most the isolating requirements specified for a –> Microsoft Office applications. disconnector. Voltage divider Device comprising resistors, inductors, capacitors, transformer(s) or a combination of T these components such that, between two Total harmonic The THD of a signal is a measurement of the points of the device, a desired fraction of the distortion (THD) harmonic distortion present and is defined as voltage applied to the device as a whole can be the ratio of the sum of the powers of all obtained. harmonic components to the power of the (Line) voltage drop The difference at a given instant between the fundamental frequency. voltages measured at two given points along a TN-S, TN-C, TN-C-S Power supply systems; in the TN-S system the line. neutral conductor and the protective-earth- Voltage regulator A tapped step autotransformer used to conductor-function is separated throughout the maintain a desired voltage level all the time. system; in the TN-C system neutral-conductor and protective-earth-conductor-function are Voltage surge A transient voltage wave propagating along a combined throughout the system; the TN-C-S line or a circuit and characterized by a rapid system is a combination of a TN-C and a TN-S increase followed by a slower decrease of the system. In one part of the system neutral- voltage. conductor and protective-earth-conductor Voltage transducer Transducer used for the measurement of an function are combined, in another part, they alternating voltage. are separate. Voltage transformer An instrument transformer in which the Total harmonic The THD of a signal is a measurement of the secondary voltage, in normal conditions of use, distortion (THD) harmonic distortion present and is defined as is substantially proportional to the primary the ratio of the sum of the powers of all voltage and differs in phase from it by an angle 11 harmonic components to the power of the which is approximately zero for an appropriate fundamental frequency. direction of the connections. Transformer A substation containing power transformers substation interconnecting two or more networks of different voltages.

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WDM Wavelength division multiplex; technology which multiplexes multiple optical carrier signals on a single optical fiber by using different wavelengths (colours) of laser light to carry different signals . WiBro South Korean service name for the international standard IEEE 802.16e (mobile WiMAX). WiMAX A wireless broadband telecommunications technology based on the IEEE 802.16 standard.

X extensible markup Markup language to faciliate the sharing of language (XML) structured data across different information systems; it is used both to encode documents and to serialize data.

Y

Z

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