Siemens Siprotec Compact Numerical Relay

The following low-power current transformer ratios are suitable for the following primary current operating ranges:

• 100 A/225 mV for a primary operating current range of 40 A 600 A
• 50 A/22.5 mV for a primary operating current range of 200 A 3000 A
• 400 A/225 mV for a primary operating current range of 200 A 2500 A
• 100 A/22.5mV for a primary operating current range of 400A 5000 A

SIPROTEC 7SJ81 is a multi-functional motor protection relay. It is designed for protection of asynchronous motors of all sizes. The relays have all the functionality to be applied as a backup relay to a transformer differential relay.

The relay provides numerous functions to respond flexibly to the system requirements and to deploy the invested capital economically. Examples for this are: exchangeable interfaces, flexible protection functions and the integrated automation level (CFC). Freely assignable LEDs and a six-line display ensure a unique and clear display of the process states. In combination with up to 9 function keys, the operating personnel can react quickly and safely in any situation. This guarantees a high operational reliability.

Highlights:

• Inputs for Low power CTs and VTs according IEC 61869-6 (formerly IEC 60044-7 and IEC 60044-8)
• Removable terminal blocks
• Binary input thresholds settable using DIGSI (3 stages)
• 9 programmable function keys
• 6-line display
• Buffer battery exchangeable from the front
• USB front port
• 2 additional communication ports
• integrated switch for low-cost and redundant optical Ethernet rings
• Ethernet redundancy protocols RSTP, PRP and HSR for highest availability
• Relay-to-relay communication through Ethernet with IEC 61850 GOOSE
• Millisecond-accurate time synchronization through Ethernet with SNTP

Details:

• The SIPROTEC Compact 7SJ81 relays can be used for line/feeder protection of high and medium-voltage networks with grounded, low-resistance grounded isolated or a compensated neutral point. The relays have all the functionality to be applied as a backup relay to a transformer differential relay.
• The SIPROTEC Compact 7SJ81 offers highest reliability at major functionality by the synergy of reliable algorithms with newly developed hardware. The reliability is proven by the experience in the field of almost 1,000,000 SIPROTEC devices. The relay provides numerous functions to respond flexibly to the system requirements and to deploy the invested capital economically. Examples for this are: exchangeable interfaces, flexible protection functions and the integrated automation level (CFC). Freely assignable LEDs and a six-line display ensure a unique and clear display of the process states. In combination with up to 9 function keys, the operating personnel can react quickly and safely in any situation. This guarantees a high operational reliability.

The SIPROTEC Compact 7RW80 is a numerical, multi function relay for connection to voltage transformers. It can be used in distribution systems, on transformers and for electrical machines. If the SIPROTEC Compact 7RW80 detects any deviation from the permitted voltage, frequency or over excitation values, it will respond according to the values set. The relay can also be applied for the purposes of system decoupling and for load shedding if ever there is a risk of a system collapse as a result of inadmissibly large frequency drops.

An integrated load restoration function allows the re-establishment of the power system after recovery of the system frequency. The 7RW80 features “flexible protection functionsâ€Â. 20 additional protection functions can be created by the user. For example, a rate-of-frequency change or a rate of- voltage change function can be created. The relay provides circuit-breaker control, additional primary switching devices (grounding switches, transfer switches and isolating switches) can also be controlled from the relay.

Automation or PLC logic functionality is also implemented in the relay. The integrated programmable logic (CFC) allows the user to add own functions, e.g. for the automation of switchgear (including: interlocking, transfer and load shedding schemes). The user is also allowed to generate user-defined messages.

The communication module is independent from the protection. It can easily be exchanged or upgraded to future communication protocols.

Highlights:

• Pluggable current and voltage terminals
• Binary input thresholds settable using DIGSI (3 stages)
• 9 programmable function keys
• 6-line display
• Buffer battery exchangeable from the front
• USB front port
• 2 additional communication ports
• Integrated switch for low-cost and redundant optical Ethernet rings
• Ethernet redundancy protocols RSTP, PRP and HSR for highest availability
• Relay-to-relay communication through Ethernet with IEC 61850 GOOSE
• Millisecond-accurate time synchronization through Ethernet with SNTP

The line differential protection SIPROTEC 7SD80 has been conceived for selective line protection of power cables and overhead lines up to 24km for all kind of starpoint configurations. The implemented phase comparison algorithm is a fast and stable method for line protection in industry and distribution grids. The protection interface communication is carried out directly without external equipment over copper wires, optical fibers or both in redundancy. The wide scope of non directional and directional functions can be applied miscellaneously as emergency functions as well as backup functions. For instance the 7SD80 enables simplified and cost saving concepts for meshed grids and busbar protection by means of reverse interlocking. Fast and selective tripping is guaranteed even if the communication fails between the relays. The scope of functions includes protection functions as well as functions for control and monitoring. The interoperable connectivity to substation control systems is give by standard protocols like IEC61850. The general concept of redundancy for protection and its communication gets completed by Ethernet redundancy protocols (PRP, HSR, RSTP) and thus increases the total system availability. Integrated functions for commissioning help and easy settings lead to short commissioning times.

Protection Interface Communication:

• Data exchange of the differential protection function takes place by means of digital communication via integrated two-wire interface and / or an integrated fiber-optic interface. By parallel use of both options communication redundancy can be realised therefore.
• Communication via the protection interface can further be used to send an intertripping command to the circuit-breaker at the opposite end, and to exchange at the same time up to 16 freely assignable binary signals between the 7SD80 relays.

Benefits:

• Pluggable current and voltage terminals
• Binary input thresholds settable using DIGSI (3 stages)
• Secondary current transformer values (1 A / 5 A) settable using DIGSI
• 9 programmable function keys
• 6-line display
• Buffer battery exchangeable from the front
• USB front port
• 2 additional communication ports
• Integrated switch for low-cost and redundant optical Ethernet rings
• Ethernet redundancy protocols RSTP, PRP and HSR for highest availability
• Relay-to-relay communication through Ethernet with IEC 61850 GOOSE
• Millisecond-accurate time synchronization through Ethernet with SNTP
• Short commissioning times by an easy parameterization and integrated commissioning help for protection and communication
• Integrated interfaces for exchanging differential protection data (fiber-optic up to 24 km/ 15 miles and/or two-wire copper cables up to 20 km/ 12 miles)
• Integrated monitoring function of the protection interface, both in the commissioning phase and in running operation
• Address ability of the protection devices for the differential protection communication in order to detect an accidental interchange of the communication cables in case of parallel cables
• Integrated non-directional and directional time-overcurrent protection
• Transmission of a circuit-breaker intertripping signal and 16 further binary signals to the opposite end
• Result: The 7DS80 is ideal for distances to 24 km/15 miles, for ring systems and as an application for differential protection.