Over-voltage protection relay PCS-985TI

phase asymmetryunder-frequencyover-frequency

Overview
PCS-985TI is a numerical transformer protection device that integrates main and backup protection within a single unit. It is designed to protect transformers at any voltage level and is typically applied to startup/standby transformers, auxiliary transformers in multi-feeder power plants, and main transformers. The device supports protection for a two-winding main transformer and one or two auxiliary transformers. PCS-985TI provides up to 80 analog input channels for current and voltage measurements. Protection functions are configurable to match site requirements, and the unit integrates fault diagnostics, disturbance and event recording, and multiple communication protocols for system integration.

Main Transformer Protection

• Current differential protection (87T)
• Transformer restricted earth fault protection (64REF)
• Negative-sequence overcurrent protection (50/51Q)
• Overexcitation protection (24)
• Phase overcurrent protection (50/51P)
• Phase overcurrent alarm elements (51PAlm)
• Ground overcurrent protection (50/51G)
• Phase overvoltage protection (59P)
• Phase undervoltage protection (27P)
• Residual overvoltage protection (59G)
• Overfrequency protection (81O)
• Underfrequency protection (81U)
• Rate-of-frequency-change protection (81R)
• Thermal overload protection (49)
• Impedance protection (21)
• Breaker failure protection (50BF)
• Pole disagreement protection (62PD)
• Breaker flashover protection (50F)
• Mechanical protection (MR)

Step-down Transformer Protection

• Current differential protection (87T)
• Transformer restricted earth fault protection (64REF)
• Phase overcurrent alarm elements (51PAlm)
• Residual overvoltage protection (59G)
• Step-down transformer HV side phase overcurrent protection (50/51P)
• Step-down transformer LV side phase overcurrent protection (50/51P)
• Step-down transformer LV side ground overcurrent protection (50/51G)

Miscellaneous

• Fault detector (FR)
• Voltage and current drift auto adjustment
• VT circuit supervision (VTS)
• CT circuit supervision (CTS)
• CT saturation detection (CTS)
• Self diagnostic
• GPS clock synchronization
• Fault recorder
• IEC61850 MMS & GOOSE for station bus
• IEC60870-5-103 protocol
• MODBUS protocol
• DNP 3.0 protocol

Technical specifications

• Model: PCS-985TI
• Device type: Numerical transformer protection relay integrating main and backup protection
• Application: Protection for transformers at any voltage level including startup/standby, auxiliary and main transformers
• Analog inputs: Up to 80 analog input channels (current and voltage)
• Configurable transformer protection functions (see protection lists above)
• Ancillary functions: fault diagnostic, disturbance recorder, event recorder
• Time synchronization: GPS clock synchronization supported
• VT/CT supervision and CT saturation detection
• Communication protocols supported: IEC61850 MMS & GOOSE, IEC60870-5-103, MODBUS, DNP 3.0
• Built-in fault recorder
• Self diagnostic and monitoring features