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SIPROTEC 7SD87 Combined line differential and distance protection

SIPROTEC 7SD87 Combined line differential and distance protection
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SIPROTEC 7SD87 Combined line differential and distance protection - 1

Description The SIPROTEC 7SD87 differential protection device is suitable for the selective protection of overhead lines and cables with singleended and multi-ended infeed of all lengths with up to 6 ends. Transformers and compensating coils in the protection range are also possible. With its modular structure, flexibility and the high-performance DIGSI 5 engineering tool, the SIPROTEC 7SD87 device offers future-oriented solutions for protection, control, automation, monitoring, and Power Quality - Basic. Main function Differential protection Interoperability of SIPROTEC 4 and SIPROTEC 5 line protection devices Tripping 1-pole and 3-pole, minimum tripping time: 9 ms Inputs and out- 12 predefined standard variants with puts 4/4 or 8/8 current/voltage transformers, 5 to 31 binary inputs, 8 to 46 binary outputs Hardware flexibi- Flexibly adjustable I/O quantity structure lity within the scope of the SIPROTEC 5 modular system Housing width 1/3 x 19 inches to 2/1 x 19 inches Applications • Line protection for all voltage levels with 1 -pole and 3-pole tripping • Phase-selective protection of overhead lines and cables with single-ended and multi-ended infeed of all lengths with up to 6 line ends • Also used in switchgear with breaker-and-a-half layout • Transformers and compensating coils in the protection zone • Detection of ground faults in isolated or arc-suppres-sion-coilground power systems in star, ring, or meshed arrangement • Serial protection communication with SIPROTEC 5 and SIPROTEC 4 devices over different distances and SIPROTEC 5 Device with Expansion Module physical media, such as optical fiber, two-wire connections, and communication networks • Phasor Measurement Unit (PMU) • Detection and recording of power-quality data in the mediumvoltage and subordinate low-voltage power system Functions DIGSI 5 permits all functions to be configured and combined as required. • Minimum tripping time: 9 ms • Main protection function is differential protection with adaptive algorithm for maximum sensitivity and stability even with the most different transformer errors, current-transformer saturation, and capacitive charging currents • Directional backup protection and various additional functions • Ground-fault detection using the pulse detection method • Detection of ground faults of any type in compensated or isolated electrical power systems using the following functions: 3I0>, V0>, transient ground fault, cos 0, sin 0, dir. detection of intermittent ground faults, harmonic detection, and admittance measurement • Detection of current-transformer saturatio

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SIPROTEC 7SD87 Combined line differential and distance protection - 2

• Fault locator plus for accurate fault location with in-homogenous line sections and targeted automatic overhead-line section reclosing (AREC) • Arc protection • Automatic frequency relief for underfrequency load shedding, taking changed infeed conditions due to decentralized power generation into consideration • Power protection, configurable as active or reactive-power 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 thermal...

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