Transmission Lines Protective Device NSR-302

NSR-302, computer-based digital HV line protective device series, can serve as the main/backup protection of 110kV and above voltage level transmission lines. When the longitudinal differential protection serves as the fast main protection, special fiber channel or multiplex one can be used as the longitudinal channel and the device supports 2048kbit/s E1 interface. When the longitudinal distance protection serves as the fast main protection, PLC or fiber channel can be used as the longitudinal channel.

  • Overview
  • Application
  • Features
  • Apecification

NSR-302 device consists of the backup protection package composed of 3-stage phase-to-phase and earth fault distance as well as 4-stage zero-sequence (directional) overcurrent protection. It is designed with auto-reclosing function and thus 3-phase auto-reclosing is available.

ANSI

FUNCTION

21P/G

Distance protection[Phase, Ground]

25

Synchronism check

67G

Zero-sequence direction overcurrent protection

68

Power swing blocking

50G

Zero-sequence instantaneous time overcurrent  protection

51P/G

Definite/Inverse time overcurrent protection[Phase, Ground]

79

Auto-reclosing

81

Low-frequency protection

SOTF

Distance acceleration break/zero-sequence acceleration break

FR

Fault records

FL

Fault location

NSR-302, computer-based digital HV line protective device series, can serve as the main/backup protection of 110kV and above voltage level transmission lines. When the longitudinal differential protection serves as the fast main protection, special fiber channel or multiplex one can be used as the longitudinal channel and the device supports 2048kbit/s E1 interface. When the longitudinal distance protection serves as the fast main protection, PLC or fiber channel can be used as the longitudinal channel.

The device supports both traditional and electronic transformer sampling as well as the combination of them on both sides of the line. For electronic transformer sampling, the digital quantity of AC current/voltage is directly connected to the protective device via the merging unit (MU). The digital input interfaces are subject to the protocols defined in IEC60044-8 or IEC61850-9-2 with the quantity meeting the demand to direct connection with several MUs. The device tripping/closing commands and other signals can be output in traditional cabling modes or in GOOSE. The diagram of the protection system is showed below:

  • Hardware design platform of high performance, modular design of CPU (central processing unit) and DSP (digital signal processor): The device is provided with main start element and protection start element.
  • The positive power of the output relay can be released only after the main start element acts so that damage of any component cannot result in unwanted action of the protection;
  • High-speed 24-point sampling, real-time parallel computation: The device can perform all the protection logic measurement and computation as well as real-time sorting of fault reports and event records at each point;
  • Whole panel, fully enclosed enclosure, separation of weak/strong current: The associated anti-disturbance measures are taken during software design, significantly improving the immunity; and the EM radiation can meet the associated codes and standards;
  • The measuring elements reflecting the power frequency variation are designed with adaptive floating thresholds so that they have strong preventative capacity of system imbalance and disturbance. Accordingly, the measuring elements can reach ultra-high speed while ensuring safety and the start elements will not start frequently thanks to the high sensitivity;
  • Advanced and reliable power swing blocking to realize reliable blocking in case of system swing and external fault(s) and reliable disconnection of the fault in case of system swing and internal fault(s);

l  AC current

1) Analog input (AI)

Rated frequency

50Hz,60Hz

Rated current (In)

1A

5A

Linear range

40A

200A





2) Digital input (DI)

IEC 60044-8 Rated current DI

463 (hexadecimal 01CFH)

IEC61850-9-2Current DI

In 1mA




l  AC voltage

1) Analog input (AI)

Rated voltage  (Un)

100V/√3

100V

 Linear range

130V

130V




2) DI

IEC 60044-8 Rated voltage DI

11585(hexadecimal 2D41H)

IEC61850-9-2Voltage DI

In 10mV




l  DC Power Supply

Rated voltage

110VDC, 220VDC

Input range

80%~120%




l  Binary Input(BI)

Rated voltage

48VDC

110VDC

125VDC

220VDC

Min. action voltage range

26.4VDC ~33.6VDC

60.5VDC~ 77VDC

68.5VDC~ 87.5VDC

121VDC ~154VDC

Max. permissive voltage

70VDC

150VDC

170VDC

300VDC

Voltage withstand level

2kVAC







l  Binary Input(BO)

Category of output contacts

Trip

Central signal

 Event record etc.

Type of output

Dry contact

Rated voltage

250VAC/DC

250VAC/DC

250VAC/DC

Overload capacity (200ms)

50A

Acting time (typical/max.)

5ms/10ms

10ms/15ms

5ms/10ms

Return time (typical/max.)

8ms/10ms

8ms/10ms

8ms/10ms

Time of contact chatter

<1ms

<1ms

<1ms









l  Mechanical Structure

Size of machine (W×H×D)

482.6mm×177mm×291mm(4U H/19" W standard enclosure)

Weight

About15kg

Protection Class (IP code) (IEC60529: 1989)

Front panel

IP40

Side

IP51

Rear panel

IP20 Designed with electric shock protection

Upper/lower bottom plates

IP40

Standards

IEC 60255-6:1988

 

Working temperature

-25°C~+55°C

 

Storage/transport temperature

-40°C~+70°C

 

Normal relative humidity

5%~95%, no condensation or icing inside

 

Atmospheric pressure

70kPa~106kPa

 

Altitude

<3000m