The transformer differential protection is a universal protection, control and automation device. 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).

Applications

• Protection of two, three and multi winding transformers and auto transformers
• Protection of transformers with restricted earth fault
• Protection of transformers in breaker-and-a-half-applications
• Autotransformer with delta winding
• Overload protection, backup protection for the downstreamed power system

X Differential protection for two winding transformers for all voltage levels

• 1 differential protection with add-on stabilization and enhance inrush stabilization for standard- or autotransformer
• Up to 2 differential ground-fault protection
• three-pole current measuring points ,2 one-pole current measuring points, three-pole voltage measuring points

O Differential protection for three winding transformers for all voltage levels

• 1 differential protection with add-on stabilization and enhance inrush stabilization
• Up to 3 differential ground-fault protection
• 5 three-pole current measuring points, 4 one-pole current measuring points, 3 three-pole voltage measuring points

O Differential protection for multiple winding transformers for all voltage levels

• 2 differential protection with add-on stabilization (protection of two transformers) and enhance inrush stabilization
• Up to 5 differential ground-fault protection
• 7 three-pole current measuring points, 5 one-pole current measuring points, 3 three-pole voltage measuring points

The device permits controlling of more than one circuit breaker and further switching devices and automation functions such as interlocks or switching sequences.

Features:

• Protection of standard power transformers, auto transformers, and motors
• Protection of standard power transformers and auto transformers
• Typical properties of a transformer differential protection such as 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
• Usable from medium up to extra-high voltage
• Universal usability of the admissible measuring points
• Adaptive adjustment of the trip characteristic to the transformer tapping
• ANSI 90 V voltage control function for two-winding transformers, three-winding transformers and system coupling transformers optionally
• Increased sensitivity in the case of ground faults close to neutral through a separate ground fault differential protection
• Differential protection synchronization via IEEE1588 PTP 2 (Powerprofile)

• Ruggedized design and conformal coated electronical boards for high electric strength and installations in harsh environments - as standard

• Redundant power supply optional
• High density of inputs and outputs using expansion modules for up to 2x19” rack device

• Optional arc protection with a tripping time of 3-4 ms for protection of assets and personal – Safety first
• Easy integration and retrofit of arc protection, transient ground-fault detection, transformer control, PMU and process bus for efficient network operation
• 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
• Optional communication module with further 3 slots plug-in modules for serial and/or Ethernet-based protocols and full availability of the communication ring when the switchgear is enabled for servicing operations by means of separate auxiliary power supply of the communication module
• 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 process bus and 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 IEEE 1558v2/PTP, 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
• Environmental product declaration according to ISO 14021, based on a life cycle assessment/life cycle analysis according to ISO 14040/44
• 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 inches to 2/1 x 19 inches with large, small or without display. Flexible adjustable and expandable I/O quantity structure within the scope of the system with 1/6 expansion modules.

Type of housing:

X Flush mounting

O Surface mounting

Power Supply:

X Standard

O Redundant

Operation panel:

X Integrated

O Detached HMI, only for surface mounting housing

Type of display:

O No display

X Small Display

O Large Display

Key switch:

X without

O with, only for flush mounting housing

LEDs/Push buttons:

X 16 LEDs

O 32 LED

O 48 LED

O 64 LED

O 80 LED

O 8 Push buttons + LEDs

Binary inputs and outputs / measuring inputs

The number of inputs and outputs is flexible and expandable with 1/6 expansion modules plugged on the 1/3 base unit of a modular system.

X 7 BI, 7 BO, 8 CT, 1/3 x 19 inches(2 winding)

O 19 BI, 23 BO, 8 CT, ½ x 19 inches(2 winding)

O 11 BI, 18 BO, 12 CT, 4 VT, 1/2 x 19 inches(3 winding)

O 23 BI, 34 BO, 12 CT, 4 VT, 2/3 x 19 inches(3 winding)

O 15 BI, 22 BO, 20 CT, 4 VT, 2/3 x 19 inches(multi winding)

O 27 BI, 38 BO, 20 CT, 4 VT, 5/6 x 19 inches(multi winding)

Rated auxiliary voltage

O DC 60 to 125 V DC

X DC 110 V-250 V, AC 100V - 230 V

Communication

The base unit has two free slots on the rear for plug-in modules for communication or special applications. The base unit is expandable with a communication module with up to three further slots for plug-in modules.

• 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
• Communication module, max 1 for each device with additional 3 slots plug-in modules for serial and/or Ethernet-based protocols and full availability of the communication ring when the switchgear is enabled for servicing operations by means of separate auxiliary power supply of the communication module
  X without
  O with one communication module for up to three additional plug-in modules
• 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 interfaces

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 interfaces

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

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

• 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 interfaces)

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 interfaces)

• 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.

O 2x optical for process bus, 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 for up to 2 km.

O 2x optical for process bus, 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 for up to 24 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 61850-9-2 Merging Unit
  IEC 61850-9-2 Process-Bus Client
  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
  IEEE 1588v2 PTP protocol via Ethernet

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, up to max. 15 sensors for modular devices
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 differntial protection (87M)
• Teleprotection for distance protection (85/21)
• Weak or no infeed echo and tripping (85/27)
• O Reverse-power protection (32R)
• Temperature supervision (38)
• Thermal overload protection (49)
• Overcurrent protection, phase (50/51 TD)
• High speed instantaneous overcurrent protection (50Hs)
• Overcurrent protection with positive sequence current I1 (50/51TD)
• 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 Differential protection for special transformers (87T)

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

O Restricted ground-fault protection (87N T)

O Generator differential protection (87G)

O Differential protection for lines with 2 ends for transformer protection (87L)

O Option for line differential protection charging current ccompnsation

O Stub-fault differential protection for breaker-and-a-half scheme (87 STUB)

O Automatic Voltage controller for transformer(90V)

O Automatic Voltage conttroller for grid coupling transformer (90V)

O Distance protection (21/21N)

O Impedance protection for transformers (21T)

O Overexcitation protection (24)

O Synchrocheck, synchronization function (25)

O Undertvoltage protection "3-phase" or "positive-sequence system V1" or "universal Vx"

O Rate-of-voltage-change protection (27R,59R)

O Undervoltage-controlled reactive power protection

O Power prtection active/reactive power (32,37)

O Power plant disconnection protection (37)

O Negative-sequence system overcurrent protection (46)

O Unbalanced-load protection (thermal)(46)

O Overvoltage protection, negative sequence system (47)

O Overvoltage protection, negative sequence/positive-sequence system (47)

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 Voltage dependent overcurrent protection (51V)

O Overvoltage protection "3-phase" or "zero-sequence system V0" or
"universal Vx"(59/59N)

O Overvoltage protection "3-phase" or "positive-sequence system V1" or "universal Vx"(59)

O Voltage-comparison supervision (60)

O Directional overcurrent protection (67)

O Directional overcurrent protection for ground faults in grounded systems(67N)

O Directional sensitive ground-fault detection for systems with resonant or
isolated neutral incl. a) 3I0>, b) V0>, c) Cos-/SinPhi,
d) Transient ground fault fct, e)Phi(V,I), f)admittance (67Ns)

O Directional stage with a harmonic
Note: This stage additionally requires the function 50Ns/71Ns or 67Ns
"Sensitive ground-fault detection for systems with resonant or isolated neutral"

O Direct Intermittent ground-fault protection

O Power-swing blocking (68)

O Automatic reclosing, 3-pole (79)

O Frequency protection "f>" or "f<" or "df/dt" (81)

O Abnormal frequency protection (81AF)

O Under Frequency Load Shedding (81U)

O Vector-jump protection

O Fault locator

O Synchrophaser measurement PMU

O Point-on-Wave Switching PoW

O Process Bus Client Protocol (PB Client)
Note: Dedicated Ethernet plug-in module for process bus required

O Additional IEC 61850-9-2 Merging Unit stream (1x) (MU)
Note: Dedicated Ethernet plug-in module for process bus required

O Circuit breaker wear monitoring

O Cyber Security: Role Base Access Control (RBAC)

O Cyber Security: IEEE 802.1x based network authentication