Overcurrent and feeder protection

SIPROTEC 7SJ85
The SIPROTEC 7SJ85 overcurrent protection has been designed specifically for the protection of feeders, lines and capacitor banks.
Features
Main function:
- Feeder and overcurrent protection for all voltage levels
Inputs and outputs:
5 predefined standard variants with
- 4 current transformers,
- 4 voltage transformers,
- 11 to 59 binary inputs,
- 9 to 33 binary outputs
Hardware flexibility:
- Flexibly adjustable and expandable I/O quantity structure within the scope of the modular SIPROTEC 5 system; 1/6 expansion modules can be added, available with large or small display, or without display
Housing width:
- 1/3 × 19 inches to 2/1 × 19 inches
As standard:
Functions
DIGSI 5 permits all functions to be configured and combined as required.
- Directional and non-directional overcurrent protection with additional functions
- Protection of up to 9 feeders with up to 40 analog inputs
- Optimized tripping times due to directional comparison and protection data communication
- Detection of ground faults of any type in compensated or isolated electrical power systems using the following functions: 3I0>, V0>, transient ground fault, cos φ, sin φ, dir. detection of intermittent ground faults, harmonic detection and admittance measurement
- Detection of intermittent ground faults with automatic blocking of static measuring functions, to avoid message and fault record flooding
- Ground fault detection using the pulse detection method
- Fault locator plus for accurate fault location with inhomogenous line sections and targeted automatic overhead-line section reclosing (AREC)
- Arc protection
- Overvoltage and undervoltage protection
- Power protection, configurable as active or reactive power protection
- Frequency protection and frequency change protection for load shedding applications
- Automatic frequency relief for underfrequency load shedding, taking changed infeed conditions due to decentralized power generation into consideration
- Protection functions for capacitor banks, such as overcurrent, overload, current unbalance, peak overvoltage, or differential protection
- Directional reactive power undervoltage protection (QU protection)
- Detection of current and voltage signals up to the 50th harmonic with high accuracy for selected protection functions (such as peak overvoltage protection for capacitors) and operational measured values
- PQ-Basic: voltage unbalance; voltage changes: overvoltage, dip, interruption; TDD, THD and Harmonics
- Point-on-wave switching
- Control, synchrocheck and switchgear interlocking protection
- Circuit-Breaker Failure Protection
- Circuit breaker reignition monitoring
- Graphical logic editor to create powerful automation functions in the device
- Single-line representation in small or large display
- Fixed integrated electrical Ethernet RJ45 for DIGSI 5 and IEC 61850 (reporting and GOOSE)
- Up to 4 pluggable communication modules, usable for different and redundant protocols (IEC 61850-8-1, IEC 61850-9-2 Client, IEC 60870-5-103, IEC 60870-5-104, Modbus TCP, DNP3 serial and TCP, PROFINET IO, PROFINET IO S2 redundancy)
- Virtual
network sharing (IEEE 802.1Q - VLAN)
- Serial protection data communication via optical fibers, two-wire connections and communication networks (IEEE C37.94, and others), including automatic switchover between ring and chain topology
- Reliable data transmission via PRP and HSR redundancy protocols
- Extensive cybersecurity functionality, such as role-based access control (RBAC), protocolling security-related events, signed firmware or authenticated network access IEEE 802.1X
- Simple, quick and secure access to the device via a standard Web browser to display all information and diagnostic data, as well as vector diagrams, single-line and device display pages
- Phasor Measurement Unit (PMU) for synchrophasor measured values and IEEE C37.118 protocol
- Time synchronization using IEEE 1588
- Control of Power Transformers
- Powerful fault recording (buffer for a max. record time of 80 sec. at 8 kHz or 320 sec. at 2 kHz)
- Auxiliary functions for simple tests and commissioning
Applications
- Detection and selective 3-pole tripping of short circuits in electrical equipment of star networks, lines with infeed at one or two ends, parallel lines and open-circuited or closed ring systems of all voltage levels up to AC 400 V
- Backup protection for differential protection devices of all kind for lines, transformers, generators, motors, and busbars
- Protection and monitoring of capacitor banks
- Phasor Measurement Unit (PMU)
- Reverse-power protection
- Load shedding applications
- Automatic switchover
- Regulation or control of power transformers (two-winding transformers, three-winding transformers, grid coupling transformers)
- Acquisition and recording of power quality data in the medium voltage and subordinate low voltage network
Benefits
- Safety due to powerful protection functions
- Purposeful and easy handling of devices and software thanks to a user-friendly design
- Cybersecurity in accordance with NERC CIP and BDEW Whitepaper requirements
- Highest availability even under extreme environmental conditions by “conformal coating“ of electronic boards
- Full compatibility between IEC 61850 Editions 1, 2.0 and 2.1