Description
A numerical differential protection relay presented in an educational format. It connects to Protection and Relay Test Set and other modules in the Power System range. It allows investigations into protection of transformers, autotransformers, generators and other electrical apparatus with two windings. The relay shows clearly the characteristics of three-phase differential protection. This includes high stability during ‘out-of-zone’ faults, zero sequence current filtering for each winding, high-speed operation, magnetising inrush restraint, amplitude and vector matching. The relay is housed in a robust enclosure with carrying handle. The unit mounts on the desk area of the Protection and Relay Test Set or other Power System product. It connects using a multi-core cable from the back of the relay to the Power System products. A Micom industrial relay forms the main part of the unit. The lecturer or student sets up different fault circuits on the Protection and Relay Test Set or other Power System product. They then use the keypad and display on the relay module to program it to the settings needed for the tests. They can also use the Micom S1 software (supplied) and a suitable computer (computer not included) to program the relay module. The user then connects the 4 mm shrouded sockets from the relay to the test circuits on the Power System product. Most tests need only one relay. However, the Protection and Relay Test Set has two sockets to test two relay modules at the same time if needed. The relay connects to the test circuits through the voltage and current transformers (VTs and CTs) built into the Power System products. This helps to show standard electrical engineering practice and the importance of CT ratio, connection and rating.
Learning Outcomes
Investigations into the performance and characteristics of an industrial differential protection relay.
Operating Conditions
Operating environment:
Laboratory environment
Storage temperature range:
–25°C to +55°C (when packed for transport)
Operating temperature range:
+5°C to +40°C
Operating relative humidity range:
30% to 95% (non-condensing)
Specifications
Dimensions:
• 300 mm x 550 mm x 278 mm
• Packed 0.16 m3
Weight:
• Net 13.5 kg
• Packed 30 kg
Maximum inputing rating : 1 A (a.c.) current input 110 VAC Line to line voltage input Supply:
Relay operating supply is 110 VAC from Power System product through a multi-core interconnecting cable.
Frequency: 50 or 60 Hz
Accuracy: ±5%
Operating time:
Typically 10 ms to 25 ms
Protection Functions:
• Diff erential protection (ANSI 87, 87T)
• Restricted Earth Fault (ANSI 64)
• Defi nite time overcurrent protection (ANSI 50P, ANSI 50Q and ANSI 50N/G)
• Inverse time overcurrent protection (ANSI 51P, ANSI 51Q and ANSI 51N/G)
• Negative Sequence Overcurrent (ANSI 46)
• Standby Earth Fault (ANSI 50N/51N)
• Thermal overload protection (ANSI 49)
Operating Conditions
Operating Environment: Laboratory Environment
Storage Temprature Range : –25°C to +55°C (when packed for transport)
Operating Temprature range: +5°C to +40°C
Operating relative humidity range: 30% to 95% (non-condensing)
