The transformer differential protection is a universal protection, control and automation device. It is especially designed for the protection two winding transformers.

It is the main protection for the transformer and contains many other protection and monitoring functions. The additional protection functions can also be used as backup protection for protected downstream objects (e.g. cables, line).

Application

• Transformer protection for two-winding transformers with versatile additional protection functions
• Transformer differential protection for single-core phase-shift transformers
• Overload protection, backup protection for the down streamed power system

Features

• Protection of standard power transformers and auto transformers
• Increased sensitivity in the case of ground faults close to neutral through a separate ground-fault differential protection
• Flexible adaptation to the transformer vector group
• Consideration of inrush and over excitation processes
• Safe behavior in the case of current transformer saturation with different degrees of saturation
• Adaptive adjustment of the trip characteristic to the transformer tapping
• Universal usability of the admissible measuring points

• Ruggedized design and conformal coated electronic boards for high electric strength and installations in harsh environments - as standard
• Easy integration and retrofit of arc protection, transient ground-fault detection, transformer control and PMU for efficient network operation
• Optional arc protection with a tripping time of 3-4 ms for protection of assets and personal – Safety first
• Single-Line representation selectable in small or large display
• Graphical logic editor to create powerful automation functions and switching sequences in the device according IEC 61131-3 standard
• Detection of current and voltage signals up to the 50th harmonic with high accuracy for selected protection functions and operational measured values
• Integrated electrical Ethernet RJ45 for Engineering PC and IEC 61850 (reporting and GOOSE)
• Two slots for optional plug-in modules for serial and/or Ethernet-based protocols
• Large number of serial and Ethernet-based protocols: IEC 60870-5-103, DNP3 serial and TCP, Modbus TCP, IEC 60870-5-104, PROFINET, and IEC 61850 Ed1 and Ed2.1
• Reliable data transmission via Ethernet redundancy protocols PRP and HSR for high-availability station communication
• IoT interface for integration in cloud based systems
• Serial protection data communication via optical fibers, two- wire connections and communication networks (SDH networks, MPLS electrical power systems, for example using IEEE C37.94, and others), including automatic switchover between ring and chain topology.
• Powerful fault recording (buffer for a max. record time of 80 sec. at 8 kHz or 320 sec. at 2 kHz)
• Easy, fast and secure access to device via Web-Browser from the device: Download of logs as files according IEEE C37.239 COMFEDE with https connection
  Fault recording: Download, delete and triggering of fault records
  Displaying of Single line diagrams and device display pages, indications, vector diagrams of energizing quantities
  Parameterization: Change of settings within an active setting-group
• Optional Phasor Measurement Unit (PMU) for detection of synchrophasor measured values and transmission with standard IEEE C37.118 protocol
• Time Synchronization with PPS, IRIG-B
• Role-based Access Control (RBAC) with central user management in RADIUS/Active Directory
• Protection against unauthorized access to device through inbuilt RADIUS authentication and authorization option
• Standard roles and rights in adherence to standards and guidelines such as IEC 62351-8, IEEE 1686 and BDEW White paper
• Syslog support for central recording and logging of security-relevant events and alarms in accordance with the requirements and regulations such as IEEE 1686, IEC 62443 and BDEW Whitepaper
• Individual Assignment of write and read permission for each device port
• Auxiliary functions for simple tests and commissioning

Housing

Robust hardware in the form of a closed housing for maximum strength in terms of voltage, EMC, climate and mechanical stress in accordance with the IEC 60255 product standard and an extended temperature range of -25°C to + 70°C.

Additional conformal coating of the electronic components for maximum availability even under extreme environmental conditions

Housing width 1/3 x 19 inch with large or small display, not expandable.

Type of housing:

X Flush mounting

Operation panel:

X Integrated

Type of display:

X Small Display

O Large Display

Key switch:

X without

LEDs/Push buttons:

X 16 LEDs

Binary inputs and outputs / measuring inputs

The number of inputs and outputs is flexible and adaptable within the 1/3 base unit of a modular system.

X 7 BI, 7 BO, 8 CT, 1/3 x 19 inch

Rated auxiliary voltage

O DC 24 - 48 V

O DC 60 V - 125 V

X DC 60 - 250 V, AC 100 V-230 V

Communication

The base unit has two free slots on the rear for plug-in modules for communication or special applications.

• USB operator interface on the front for notebook or PC
• D-Sub 9-interface, rear for time synchronization
• Integrated Ethernet interface
  X for Engineering Tool
  O for Engineering Tool and IEC 61850 Reporting and GOOSE
  O for Engineering Tool and IEC 61850 Reporting
• Serial Plug-In modules for asynchronous serial protocols like IEC 60870-5-103, DNP for system port
  X Without
  O electrical, 1 interface
  O electrical, 2 interface
  O optical 820 nm, 1.5 to 2km ,1 interface
  O optical 820 nm, 1.5 km to 2km, 2 interface
• Serial Plug-in modules for protection interface for unidirectional data exchange

X without

O optical 1300 nm, max. 24 km via 2 single mode optical fibers or max. 4 km via 2 multimode optical fibers, 1 interface

O optical 1300 nm, max. 24 km via 2 single mode optical fibers or max. 4 km via 2 multimode optical fibers, 2 interface

O optical 1300 nm, max. 60 km via single mode optical fiber, 1 interface

O optical 1300 nm, 60 km via single mode optical fiber, 2 interface

O optical 1550nm, 100 km via single mode optical fiber, 1 interface

O optical 1550nm, 100 km via single mode optical fiber , 2 interface

• Serial Plug-in modules for protection interface for bidirectional data exchange

O without

O optical 1300 nm, max. 40 km via one single- mode optical fiber (with integrated fiber-optic multiplexer, 1 interface)

O optical 1300 nm, max. 40 km via one single- mode optical fiber (with integrated fiber-optic multiplexer, 2 interface)

O optical 1550 nm, max. 40 km via one single- mode optical fiber (with integrated fiber-optic multiplexer, 1 interface)

O optical 1550 nm, max. 40 km via one single- mode optical fiber (with integrated fiber-optic multiplexer, 2 interface)

• Plug-in Modules for Ethernet

O Without

O 2x RJ45 electrical, configurable with or without integrated switch with max. distance of 20 meters

O 2x optical duplex LC 1300 nm interface, configurable with or without integrated switch. The maximum optically permitted distance via 50/125 µm or 62.5/125 µm multimode optical fibers is 2 km.
The optical transmission and receiving level are measured in the module and can be displayed.

In accordance with the selected communication interface the required communication protocol should be easily activated via the engineering tool depending on the selected type of serial or Ethernet plug-in module

• Serial protocols
  IEC 60870-5-103
  DNP3 serial
• Ethernet protocols
  IEC 61850 Edition 2.1
  IEC 61850-8-1 Client-Sever Communication
  IEC 61850-8-1 GOOSE
  IEC 60870-5-104
  DNP3 TCP
  Modbus TCP
  PROFINET IO
  IEEE C37.118 protocol (Synchrophasor, PMU)
• Additional Ethernet protocols and services
  DHCP, DCP (with automatic IP configuration)
  Line mode
  RSTP, PRP, HSR Ethernet ring redundancy
  SNTP time synchronization via Ethernet
  SNMP V3 network management protocol

Plug-in modules for various applications

O Measuring-transducer module with four 20-mA analog inputs

O Arc protection module with up to 3 optical point or line sensors per arc protection plug-in module
X Point sensors with line lengths from 3 m to 35 m.
O Line sensors detect arcs along the entire sensor length.
  Lengths from 5 m to 40 m are available.
  Line sensors are connected via a line to the arc protection module.

Functionality

The protection device is equipped with the following protection functions:

X Basic functions

• Transformer differential protection (87T)
• Transformer differential protection Node for auto transformer (87T Node)
• Motor differential protection (87M)
• Temperature supervision (38)
• Thermal overload protection (49)
• Overcurrent protection, phase (50/51 TD)
• High speed instantaneous overcurrent protection (50Hs)
• Overcurrent protection, ground (50N/51N TD)
• Overcurrent protection, 1-phase (50N/51N TD)

• Trip-circuit supervision (74TC)
• Closed-circuit supervision supervision (74CC)
• Lockout (86)
• Measured values
• Basic PQ measurements: THD and harmonics
• Switching-statistic counters
• Logic editor
• Inrush-current detection
• External trip initiation
• Control
• Monitoring and supervision
• Fault recording of analog and binary signals
• Frequency tracking groups
• Temperature acquisition via communication

Optional functions

O Transformer differential protection for phase angle regulating transformer (single core) (87T)

O Restricted ground-fault protection (87N T)

O Generator differential protection (87G)

O Negative-sequence system overcurrent protection (46)

O Unbalanced-load protection (thermal)(46)

O Hot spot calculation (49)

O Overcurrent protection, phase (50/51 TD)

O Instantaneous tripping at switch onto fault SOTF

O Sensitive ground-current detection for systems with resonant or isolated
neutral a)3I0>, b)admittance Y0>, c)3I0-harm> (50Ns/51Ns)

O Intermittent ground-fault protection

O Circuit breaker failure protection (50BF)

O Circuit breaker restrike protection (50RS)

O Synchrophaser measurement PMU

O Circuit breaker wear monitoring

O Cyber Security: Role Base Access Control (RBAC)

O Cyber Security: IEEE 802.1x based network authentication