PCS-9671 is a compact numerical relay for two-winding transformers. It can be utilized for reactor or stub-bus current differential protection. It also can be used to protect reactors or implemented as a stub current differential protection in a oneand- a-half breaker arrangement. The restraint current differential protection, unrestraint differential protection and restricted earth fault protection are provided.
Comprehensive flexibility is provided via the modular hardware design, scalable function library, programmable logics, configurable I/Os and definable LEDs. This allows users to create customized schemes for specific projects. Two fixed LEDs and 18 configurable 3-color LEDs (Green/Yellow/Red) are provided. The relay is compatible with IEC 61850 station bus and process bus applications. It supports IEC 61850-8-1 MMS, GOOSE and IEC 61850-9-2 Sampling Value. The RJ-45 faceplate port is implemented in effort to make testing, setting, commissioning and maintenance easier.
Functons:
Protection and Control
Restraint current differential protection. (87T)
Unrestraint current differential protection. (87UT)
Restricted earth fault protection (64REF)
Inrush current blocking by 2nd and 3rd harmonic
Overexcitation blocking by 5th harmonic
CT saturation detection
Phase overcurrent protection (50/51P)
Zero sequence overcurrent protection (50/51G)
Negative sequence overcurrent protection (46)
Thermal protection (49)
Undervoltage and overvoltage protection (27/59)
Zero sequence overvoltage protection (59G)
Negative sequence overvoltage protection (47)
Overexcitation protection (24)
CT circuit supervision. (CTS)
Management
1024 supervision alarm records, 1024 control operation records and 1024 user operation records
64 fault and disturbance records
1024 SOE records
Up to four 10Base-T/100Base-TX (RJ45) ports or two 100Base-FX ports with IEC 61850-8-1 MMS, IEC 60870-5- 103 over TCP/IP
Two RS-485 rear ports with IEC 60870-5-103
Up to six 100Base-FX ports with IEC 61850-9-2 Sampling Value and GOOSE
One RS-485 rear port for clock synchronization
One RS-232 rear port for printer
One faceplate RJ-45 port for testing and setting
Clock synchronization via pulse, IRIG-B and SNTP
Auxiliary Testing Functions
Virtual tripping report generation and communication testing
Virtual self-supervision report generation and communication testing.
Virtual binary input state change report generation and communication testing.
Binary output testing.
Manual triggering fault recording.
Features:
The unique hardware design with two independent data acquisition paths can prevent the mal-operation due to hardware component failure. It significantly enhances the protection reliability.
Various methods of GPS time synchronization are supported in this relay, including SNTP, PPS (Pulse-Per-Second)and IRIG-B synchronization.
The device can communicate with SAS or RTU via different communication intermediates: Ethernet network, RS-485 serial ports. The communication protocol of this device is optional: IEC61850, IEC60870-5-103 or DNP3.0.
Complete event recording function is provided: 1024 supervision records, 1024 control operation records, 1024 user operation records and 1024 SOE records can be recorded.
Powerful fault and disturbance recording functions are supported: 64 fault or disturbance waves, the duration of a wave recording is configurable.
Y→Δ transfer method is used to compensate phase angle of secondary current, and correction coefficients are adopted to complete amplitude compensation.
Users may set the vector group in each side of the transformer. Furthermore,, 24 vector groups are available for two-winding transformer, and 288 vector groups are available for 3-winding transformer.
Three slopes biased differential protection is adopted in order to avoid mal-operation caused by unbalance current during external faults.
The 2nd, 3rd and 5th harmonic blocking functions for biased differential protection are available. The 2nd and 3rd harmonics are selectable to identify inrush current, and the 5th harmonic is used to detect possible overexcitation conditions. In addition, phase segregated blocking mode and crossing-blocking mode are provided for selection.
The CT transient detection element based on the ratio of residual current to positive current is adopted to eliminate the influence on REF due to the CT transient characteristic difference.