Functional block diagram of the S24/L relay
General presentation
The S24/L (V3) relay is a multifunction digital protection mainly intended for the main or back-up protection of overhead lines or feeder cables in distribution networks. The main function of this relay is distance protection.
It belongs to the S24 family, part of the SMARTLINE range. These devices offer a wide set of functions in a compact housing. Among other uses, they are particularly suited to the LV compartments of MV switchgear cubicles.
The particularity of these relays is that, although they belong to the SMARTLINE range, their hardware and firmware are the same as those of the relays making up the PROTECTA range. They therefore share the same physical and electrical characteristics. This provides extensive field experience of their use and operation, as well as consistent and optimum manufacturing lead times. The main difference between the two ranges is the housing.
The EuroCAP configuration tool, available free of charge, provides a user-friendly and flexible application for protection, control and measurement functions, ensuring that the protection devices are fully customisable.
General features
- Native IEC 61850, Edition 2 compatible
- Standard 144 × 144 mm housing
- The predefined factory configuration can be customised to the user’s specifications with the EuroCAP tool
- Various types of HMI:
- Colour touch screen
- Monochrome (B&W) alphanumeric display with 4 touch buttons.
- Built-in web server as well as extended measurement, control and monitoring functions.
- User-configurable LCD displays for the colour touch HMI, able to show single line diagrams with position indication and control of the switching devices, as well as measurement values of the controllable objects
- Adaptive protection
- Circuit breaker monitoring and control
- High-capacity disturbance recorder (DRE) and event logging:
- DRE supporting up to 32 analogue signal channels and 64 digital signal channels
- The event recorder can store more than 10,000 events
- Various mounting types:
- Flush-mounted;
- Semi-flush-mounted;
- DIN rail
- Numerous communication protocols:
- Ethernet communication: IEC 61850; IEC 60870-5-104; DNP3.0 TCP; Modbus TCP
- Serial communication: DNP3.0; IEC 60870-5-101/103; MODBUS, SPA
- Legacy network protocols over 100Base-FX and 10/100Base-TX (RJ45)
- Optional communication ports:
- Ethernet over optical fibre (MM/ST, SM/FC),
- RJ45,
- POF serial,
- Serial over optical fibre,
- RS-485/422
- Simultaneous support of several communication protocols
- Built-in self-monitoring function (hardware and software) – Watchdog
- Various time sources available:
- NTP server;
- IRIG B
Applications
The S24/L (V3) protection is mainly used as main or back-up protection of overhead lines or feeder cables in distribution networks.
It provides protection over 5 zones. The configuration includes the simplified version of this function: it generates three-phase tripping commands, but in the event of cross-country faults it also uses the phase preference logic. In addition, the S24/L integrates various versatile line protection functions, such as three-phase, residual and negative sequence overcurrent protection, line thermal overload protection, etc. The voltage measurement adds a directional element to the configured phase and residual overcurrent functions, in addition to the three-phase undervoltage and overvoltage and the residual overvoltage functions. Frequency-based functions are also available. It can be used as a back-up protection relay for downstream equipment (for example distribution lines and cables). The synchrocheck and auto-reclosing functions are also part of the standard configuration.
The S24/L relay integrates a wide range of control and supervision functions, providing full control and user-defined interlocking schemes for the substation switchgear.
Field of application
- Underimpedance distance protection function,
- Overcurrent, directional overcurrent and thermal overload protection functions for overhead lines and cables
- Overvoltage and undervoltage protection functions, as well as residual overvoltage and negative sequence voltage protection
- Frequency-based functions
- Overpower and underpower protection function
- The protection functions implemented provide back-up protection for downstream equipment (for example feeders, cables, etc.)
- Synchrocheck function and auto-reclosing function
- Circuit breaker failure protection function
- Current transformer (CT) current unbalance detection
- Voltage transformer (VT) supervision function
- Programmable interlocking schemes
Protection and control functions
The S24/L (V3) protection measures the three phase currents, the residual current component as well as the three-phase voltages and the zero sequence voltage component. In addition to the current- and voltage-based functions, these measurements allow the directionality of the phase and residual overcurrent functions to be extended.
The main protection function in this application is the distance protection function. The configuration includes the simplified version of this function: it generates three-phase tripping commands, but in the event of cross-country faults it also uses the phase preference logic. The range of functions is completed by the auto-reclosing function.
Frequency is also evaluated from the voltage measurement in order to implement frequency-based protection functions. The configuration is designed to meet the protection requirements of a medium voltage link.
General documentation : Smartline S24 DataSheet – 19AA1121500B
Operation manual : S24L OMA 23AA3351315
Click on the link to access the technical documentation to attach to your order : DOCACOM_S24
