PCS-931

Read more on the web

www.nrelect.com 35read more on www.nrelect.com

Optionally, the PCS-931 incorporates two sets of CT input for dual-breaker application. The dual-breaker failure protection, dual-breaker auto-reclosing and stub protection are integrated for one-and-a-half breaker and ring breaker arrangements. To enhance the accuracy of data sampling, the frequency-tracking function is used to trace the real-time current/voltage value. The PCS-931 adopts the advanced UAPC multi-processor platform which is fully complied with IEC 61850. It provides the interfaces for station bus and process bus respectively and supports IEC 61850-8-1 MMS, GOOSE, IEC 61850-9-2 Sampling Value. And it provides the RJ-45 front port for testing and setting to make commissioning and maintenance easier.

FunctionsProtection and Control

Phase-segregated current differential protection. (87)Dynamic charging current compensation technology and CT saturation detection are integrated to realize a combination of both sensitivity and security of current differential protec-tion.

Zero sequence current differential protection. (87)Zero sequence current differential protection integrates the dynamic charging current compensation technology and CT saturation detection, aiming at quickly detecting and clearing the ground fault.

DPFC differential protection. (87)

Functional Block Diagram

The PCS-931 relay provides a full-scheme numerical line protection with phase-segregated current differential protection, zero sequence current differential protection, stepped distance protection, current protection and voltage protection with single and/or three pole tripping and auto-reclosing. It introduces an extensive functional library, programmable logic and configurable I/O, intending for the use on overhead lines and underground cables of all voltage levels, including series compensated lines, double-circuit lines, three-terminal lines, heavily loaded lines, weak infeed (WI), short lines and extremely long lines. An extra communication port is optional to provide dual protection channels for three-terminal application and redundant application. The PCS-931 adopts a wide range of innovative patented technologies, such as DPFC (Deviation Power Frequency Component) distance protection and unique power swing blocking logic, to guarantee accurate and reliable operations.

Line Differential Relay

Deviation of Power Frequency Component (DPFC) differen-tial current protection is sensitive to high resistance fault and is immune to load current variation.

DPFC distance protection. (21D)Innovative Deviation of Power Frequency Component(DPFC) distance protection can quickly clear faults.

Four zones of phase-to-phase distance protection. (21P)Four zones of phase-to-phase distance protection integrates the memorized positive sequence voltage polarization, di-rection characteristic, load blinder and unique low-voltage distance element. The fourth zone is the reversal directional protection. Mho and quadrilateral characteristics are pro-vided for selection.

Four zones of phase-to-ground distance protection. (21G)Four zones of phase-to-ground distance protection inte-grates the memorized positive sequence voltage polariza-tion, reactance characteristic, direction characteristic, load blinder and unique low-voltage distance element. The fourth zone is the reversal directional protection. Mho and quadri-lateral characteristics are provided for selection.

Four stages of directional phase overcurrent protection. (67P, 50/51P)Overcurrent protection can be supervised by voltage ele-ment and directional element. IDMT curves complied with IEC and ANSI standard are present for selection.

Four stages of directional zero sequence overcurrent protec-tion. (67N, 50/51N)

PCS-931


www.nrelect.com36 read more on www.nrelect.com

Overcurrent protection can be supervised by voltage ele-ment and directional element. IDMT curves complied with IEC and ANSI standard are present for selection.

Breaker failure protection for one or two breakers (50BF)Breaker failure protection can be applied to one breaker and two breakers.

Two stages of under voltage protection and two stages of over voltage protection (27/59)Under/over phase voltage protection and under/over (positive sequence, negative sequence or zero sequence) voltage protection are provided.

Four stages of underfrequency protection and four stages of over frequency protection (81)Frequency is calculated reference to the positive sequence voltage. The protection can be supervised by the df/dt ele-ment and the undervoltage element.

Stub protection for T-Zone in 3/2 breaker arrangement. (50S)Stub protection is introduced to protect T-zone in a one-and-a-half breaker scheme or a ring breaker scheme.

Time phase overcurrent protection during VT failure. (51P VT)Time phase overcurrent protection will be enabled if phase-to-phase distance protection is blocked by VT failure.

Time zero sequence overcurrent protection during VT failure. (51N VT)Time zero sequence overcurrent protection will be enabled if phase-to-ground distance protection is blocked by VT failure.

Broken conductor protection (46BC)The ratio of negative to positive phase sequence current (2/1) is adopted to detect the broken conduct.

Switch-onto-fault (SOTF) logic.Switch-onto-fault logic is used to clear fault during manually-closing and auto-reclosing.

Out-of-step tripping (78)The out-of-step status is detected in the relay and it can be used to trip the transmission line.

Unique power swing blocking logic. (68)The power swing blocking logic can prevent mal-operation during external fault a power swing and clear the internal fault in power swing.

Thermal overload protection. (49)The output of thermal overload protection can be set to trip-ping or alarm.

Dead zone protection (50DZ)It is provided to clear the dead zone fault between CT and breaker.

Synchronism check. (25)Synchronism check and dead bus or dead line check are both provided for auto-reclosing.

Auto-reclosing (single and/or three-pole for one or two breakers). (79)

Single/three pole auto-reclosing is applicable to one or two breakers. Priority logic is integrated for use on one-and-a-half breaker application and ring breaker application.

Voltage and current drift auto adjustment.The relay continually and automatically traces the voltage and current drifts and adjusts the zero point to the normal value.

Frequency tracking.Frequency tracking is provided to accommodate the fre-quency shift in power system.

Monitoring and Metering

CT failure supervision.

VT failure supervision.

Tripping circuit supervision.

Self diagnostic.

Auxiliary power supervision.

Event recorder including 1024 disturbance records, 1024 binary events, 1024 supervision events and 1024 operating logs.

Counter of circuit breaker operation (single-pole tripping, three-pole tripping and reclosing).

Disturbance recorder including 64 disturbance records with waveforms (The file format of disturbance recorder is compatible with international COMTRADE file.)

Communications

Single- or double- pilot channel based on dedicated optical fiber or multiplex channel(C37.94 or G.703 with external converter).

Two 10Base-T/100Base-TX (RJ45) ports and two optional 100Base-FX ports with IEC 61850-8-1 MMS and GOOSE for non-time-critical message, IEC 60870-5-103 over TCP/IP or DNP 3.0.

Two RS-485 rear ports with IEC 60870-5-103.

Six or Eight 100Base-FX ports with IEC 61850-9-2 Sampling Value and GOOSE for time-critical message

One RS-485 rear port for clock synchronization

One RS-232 rear port for printer

One faceplate RJ45 port for testing and setting

Clock synchronization via Pulse-Per-Second, IRIG-B and SNTP

Features The PCS-931 can quickly clear the internal fault for the

whole line and the typical operation time is 10ms for a close-in fault and 25ms for a remote fault.

The relay is based on NRs well established and proven UAPC hardware platform with multi-processor architecture. The multi CPU technology supports parallel operation simultaneously.

The PCS-931 adopts high restraint factor and self-adaptive floating restraint threshold to realize both high reliability and sensitivity even in the CT saturation.



auto-reclosing is integrated.

Instantaneous, definite time and inverse time (IDMT) characteristics are available in phase overcurrent protection and the zero sequence overcurrent protection which can be controlled by directional protection and/or under voltage protection through logic setting.

Three zones of forward distance element and one zone of reverse distance element are provided.

Users can select either Mho or quadrangle with Mho characteristics for distance protection. The load blinder function is also integrated.

The independent phase selection element can select the faulty phase and make a phase trip correctly, even for a high resistance fault.

The two independent data acquisition paths can prevent any undesired trip caused by component failure. One works as a fault detector and the other is designed for protection and its logic. Tripping outputs are supervised by the fault detector to prevent any mal-operation.

Optional connector type: one is the plug in/out terminal connector and the other is the screw terminal connector. The unique plug in/out terminal connectors are used to connect the rear panel to the terminal blocks on the rack or cabinet, making on-site commissioning and replacement much easier than using traditional screw terminals.

The relay is compatible with IEC 61850-8-1 MMS, GOOSE and IEC 61850-9-2 Sampling Value and provides the independent interfaces for station bus and process bus respectively.

Technical dataPower Supply

Standard IEC 60255-11:2008

Voltage Range 88 to 300 Vdc or 88 to 264 Vac Permissible AC ripple voltage 15% of the nominal auxiliary voltage

BurdenQuiescent condition



Analog VoltageStandard IEC 60255-6, IEC60288 Phase rotation ABCNominal frequency (fn) 50Hz, 60HzNominal range fn5HzRated phase-to-phase voltage (Un) 100~130V 200V (Broken delta for residual voltage) linear to 1~170V 1~233V

Thermal withstand capabilitycontinuously 200V 220V10s 260V 380V1s 300V 420V

Burden < 0.20VA/phase @Un < 0.8VA/phase@Un

Binary InputsStandard IEC 60255-1:2009Rated voltage 24V 30V 48V 110V 125V 220V 250V Rated current 1.2mA 1.5mA 2.4mA 1.1mA 1.25mA 2.2mA 2.5mAPickup voltage 13V~17V 17V~21V 26V~34V 60.5V~77V 60.5V~77V 121V~154V 121V~154VDropout voltage 90% of pickup voltageMaximum permissive voltage 300VdcWithstand 2000VAC, 2800VDC(continuously)Resolving time for logic input



- Ethernet PortConnector type RJ-45Transmission rate 100Mbits/sTransmission standard 10Base-T/100Base-TXTransmission distance



Surge immunity test

Per IEC 60255-22-5:2008Power supply, AC input, I/O port: class IV, 1.2/50usCommon mode: 4kVDifferential mode: 2kV

Conducted RF Electromagnetic DisturbancePer IEC 60255-22-6:2001Power supply, AC, I/O, Comm. Terminal: Class III, 10Vrms, 150 kHz~80MHz

Power Frequency Magnetic Field ImmunityPer IEC 61000-4-8:2001class V, 100A/m for 1min, 1000A/m for 3s

Pulse Magnetic Field ImmunityPer IEC 61000-4-9:2001class V, 6.4/16s, 1000A/m for 3s

Damped oscillatory magnetic field immunityIEC 61000-4-10:2001class V, 100kHz & 1MHz100A/m

Auxiliary power supply performanceIEC60255-11: 2008Voltage dips: Up to 300ms for dips to 40% of rated voltage without resetVoltage short interruptions: 100ms for interruption without rebooting

PCS-931

Documents

Transcript of PCS-931