Multifunction Protection Relay with Synchronization Block 7SJ640

The following functions are available

1. Protection functions :-                                                                                                                                                              •Time-overcurrent protection
   • Directional time-overcurrent protection
   • Sensitive dir./non-dir. earth-fault detection
   • Displacement voltage
   • Intermittent earth-fault protection
   • High-impedance restricted earth fault
   • Inrush restraint
   • Motor protection
   • Overload protection
   • Temperature monitoring
   • Under-/overvoltage protection
   • Under-/overfrequency protection
   • Rate-of-frequency-change protection
   • Power protection (e.g. reverse, factor)
   • Breaker failure protection
   • Negative-sequence protection
   • Phase-sequence monitoring
   • Synchronization
   • Auto-reclosure
   • Fault locator
   • Lockout
2. Control functions/programmable logic :-
   • Flexible number of switching devices
   • Position of switching elements is shown on the graphic display
   • Local/remote switching via key operated switch
   • Control via keyboard, binary inputs, DIGSI 4 or SCADA system
   • Extended user-defined logic with CFC (e.g. interlocking)
3. Monitoring functions :-
   • Operational measured values V, I, f,…
   • Energy metering values Wp, Wq
   • Circuit-breaker wear monitoring
   • Slave pointer
   • Trip circuit supervision
   • Fuse failure monitor
   • 8 oscillographic fault records
   • Motor statistics

This Multifunction Protection Relay with Synchronization Block is easily insert in your schematic diagram and connect as you like way.

The SIPROTEC 4 7SJ64 unit is a numerical protection relay that also performs control and monitoring functions and therefore supports
the user in cost-effective power system management, and ensures reliable supply of electric power to the customers. Local operation has been designed according to ergonomic criteria. A large, easy-to-read graphic display was a major design aim. The relay is suited for networks
that are radial or looped, and for lines with single or multi-terminal feeds. The SIPROTEC 4 7SJ64 is equipped with a synchronization function which provides the operation modes ‘synchronization check’ (classical) and ‘synchronous/asynchronous switching’ (which takes the CB mechanical delay into consideration). Motor protection comprises undercurrent monitoring, starting time supervision, restart inhibit, locked rotor, load jam protection as well as motor statistics. The 7SJ64 is featuring the “flexible protection functions”. Up to 20 protection functions can be added according to individual requirements. Thus, for example, rate-of-frequency-change protection or reverse power protection can be implemented. The relay provides easy-to-use local control and automation functions. The number of controllable switch gear depends only on the number of available inputs and outputs. The integrated programmable logic (CFC) allows the user to implement their own functions, e.g. for the automation of switch gear (interlocking). CFC capacity is much larger compared to 7SJ63 due to extended CPU power. The user is able to generate user-defined messages as well. The flexible communication interfaces are open for modern communication architectures with control systems. This function is based on the phase-selective measurement of the three phase currents andv the earth current (four transformers). Three definite-time over current protection elements (DMT) exist both for the phases and for the earth. The current threshold and the delay time can be set in a wide range. In addition, inverse-time over current protection characteristics (IDMTL) can be activated. The inverse-time function provides – as an option – voltage-restraint or voltage-controlled operating modes. With the “flexible protection functions”, further definite-time over current stages can be implemented in the 7SJ64 unit.

1. Control :-
   The integrated control function permits control of disconnect devices (electrically operated/motorized switches) or circuit-breakers
   via the integrated operator panel, binary inputs, DIGSI 4 or the control and protection system (e.g. SICAM). The present status (or
   position) of the primary equipment can be displayed. 7SJ64 supports substations with single and duplicate busbars. The number of
   elements that can be controlled (usually 1 to 5) is only restricted by the number of inputs and outputs available. A full range of command processing functions is provided.
2. Programmable logic :-
   The integrated logic characteristics (CFC) allow users to implement their own functions for automation of switch gear (interlocking)
   or a substation via a graphic user interface. Due to extended CPU power, the programmable logic capacity is much larger compared to 7SJ63. The user can also generate user-defined messages.
3. Line protection :-
   The 7SJ64 units can be used for line protection of high and medium-voltage networks with earthed, low-resistance earthed, isolated or compensated neutral point.
4. Synchronization :-
   In order to connect two components of a powersystem, the relay provides a synchronization function which verifies that switching
   ON does not endanger the stability of the power system. The synchronization function provides the operation modes ‘synchro-check’ (classical) and ‘synchronous/asynchronous switching’ (which takes the c.-b. mechanical delay into consideration).
5. Motor protection :-
   When protecting motors, the relays are suitable for asynchronous machines of all sizes.
6. Transformer protection :-
   The 7SJ64 units perform all functions of backup protection supplementary to transformer differential protection. The inrush
   suppression effectively prevents tripping by inrush currents. The high-impedance restricted earth-fault protection detects short-circuits and insulation faults of the transformer.
7. Backup protection :-
   The relays can be used universally for backup protection.
8. Flexible protection functions :-
   By configuring a connection between a standard protection logic and any measured or derived quantity, the functional scope of the relays can be easily expanded by up to 20 protection stages or protection functions.
9. Metering values :-
   Extensive measured values, limit values and metered values permit improved system management.