Functional block diagram of the S24/G relay
General presentation
The S24/G relay is a multifunction digital protection relay mainly used for the protection of generators of any kind. It consists of a three-phase and earth current unit and a three-phase and earth voltage unit.
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/G relay is a multifunction digital relay. It offers all the functionalities of the S24/Fr relay, with the addition of the “loss of excitation” function. This makes it a perfect protection for medium power generators (between 3 MW and 15 MW).
This protection includes various versatile generator protection functions based on both current and voltage measurement, such as three-phase, residual and unbalance overcurrent protection, undercurrent protection, thermal overload protection and directional three-phase and residual overcurrent protection, loss of excitation and reverse power. The voltage- and frequency-based functions can serve as main protection for generators. Voltage-dependent overcurrent, vector shift, overvoltage and undervoltage functions, as well as overfrequency and underfrequency, rate-of-change-of-frequency protection, etc., are also available.
It also integrates a wide range of control and supervision functions, providing full control and user-defined interlocking schemes for the substation switchgear.
Field of application
- Three-phase, residual and directional overcurrent protection, as well as thermal overload protection
- Overvoltage and undervoltage protection
- Loss of excitation protection
- Additional protection and control functions, in particular for generators: unbalance overcurrent, voltage-dependent overcurrent, vector shift, reverse power, frequency-based protection, overexcitation detection
- The protection functions implemented provide back-up protection for downstream equipment (for example distribution lines, cables, etc.)
- Optional restricted earth fault protection function for simple transformer protection
- 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/G (V2bis) configuration measures the three-phase currents, the residual current component as well as the three-phase voltages. These measurements add a directional element to the phase and residual overcurrent functions, in addition to the current- and voltage-based functions. Frequency is also evaluated (from the voltage measurement) in order to implement frequency-based protection functions. It is intended to protect medium power generators rated between approximately 3 MW and 15 MW.
The earth differential protection function against single-phase faults close to the machine is available as an option for generators operating in parallel, each with its own earthing resistor.
Click on the link to access the technical documentation to attach to your order : DOCACOM_S24
