DSO TSO Technopedia

Factsheets:

AC Power Transformers (with Tap Changer)

Power transformers are an essential component of the Alternating Current (AC) electrical power system, enabling the exchange of the electrical power between grids with different voltage levels. Power transformers must be built to withstand severe electrical and mechanical stress from transients and fault currents.

Advanced Conductors

High-Temperature (HT) Low Sag (LS) conductors can operate at continuous temperatures over 100 °C without strength degradation due to annealing. At the same time, they have a sag performance better than their equivalent conventional conductors (and only similar sag performance at certain temperature ranges), known as ACSR (Aluminium Conductor Steel Reinforced).

Asset Management AIM

In today's European TSOs, asset management has generally shown a higher maturity for substation primary assets [1,2] than for overhead lines (OHL)/cables [3]. Moreover, its application to data and software is primitive despite the close attention paid to treating them as assets [4].

Circuit Breakers

An alternating current (AC) circuit breaker refers to a mechanical switching device that is used to close or open an electrical circuit. Circuit breakers are capable of carrying and breaking currents under normal and abnormal (e.g. short circuit) grid conditions.

Digital Fault Recorders

Digital fault recorders (DFRs) in the power system are devices that sample the analogue values of voltage and current and convert them to a digital format after being triggered by events or signals from protection relays. This digital data is then used for various analyses of electrical system performance. The analogue measurements are delivered by conventional voltage and current transformers or by modern sensors such as optical current transformers.

Digital Secondary Substations

The technology supports the digitalization of DSO (Distribution System Operator) grids in both low-voltage (LV) and medium-voltage (MV) sectors. It enables real-time monitoring of key parameters such as voltage and power from the electrical grid.

Digital Twins

The pan-European Transmission system is a Cyber-Physical System (CPS) with standards already framing their development: the International Electrotechnical Commission (IEC) 60870-5-101 [1] and the IEC 60870-5-104 [2]. Today, the IEC standard 61850 is the successor of such developments [3]:

Dynamic Line Rating (DLR)

Dynamic Line Rating (DLR) is a method for determining the actual current-carrying capacity (ampacity) of overhead transmission lines (OHL)s in (near) real time or in the future. Unlike static ratings, DLR dynamically adjusts the line rating based on actual weather conditions.

HTS Cables

High-temperature superconducting (HTS) cables use superconducting materials that, when cooled to cryogenic temperatures (below -160°C), exhibit near-zero DC electrical resistance. In practical power applications, overall system losses still occur due to AC effects in the superconductor and the energy required for cryogenic cooling. HTS cables can therefore be attractive where the cooling energy and system losses are significantly lower than the losses of conventional cable alternatives for the same power transfer.

Software Defined Security

Operational security mechanisms in Information and Communication Technology (ICT) systems are currently facing challenges in dealing with new network threats and attacks. Software-Defined Security (SDS or SDSec) has been proposed to meet such challenges. It is a generic security model within which information security is controlled and managed by security software. The well-known functions of network security devices, such as firewalling, intrusion detection, access controls and network segmentation, are extracted from hardware devices and framed into a software layer. Protection is based on logical policies which are no longer tied to any security device [1].

Static Synchronous Series Compensators (SSSC)

The static synchronous series compensator (SSSC) is a device that employs controllable power electronic components for series reactive power compensation. For this reason, the technology is categorised as a flexible alternating current transmission system (FACTS). It outputs a series-injected voltage that leads or lags the line current by 90°, thus emulating a controllable inductive or capacitive reactance.

Voltage Source Converters (VSC)

Voltage Source Converters (VSCs) are self-commutated converters based on semiconductors, as insulated gate bipolar transistors (IGBTs), that can conduct or isolate independently on the current and voltage cycle. VSCs can generate Alternating Current (AC) voltages without the need to rely on an AC system. This allows for independent rapid control of both active and reactive power and black start capability. VSCs maintain a constant polarity of the Direct Current (DC) voltage and control the DC current flow. This ability enables the application of cross-linked polyethylene (XLPE) cables.