Load Encroachment

Load Encroachment

·????????Impedance of Heavy load can actually be less than the impedance of some fault. Yet protection must be selective enough to discriminate between load and fault.

·????????Load encroachment occurs only when the impedance crosses the load ability limit of the operating characteristics

·????????Load encroachment is defined as the measured impedance due to load current & voltage exceeding the impedance determined by the load ability limit of the impedance relay at an specific factor.

·????????Load measured by the relay is a function of the direction of power and power factor of load.

·????????Load encroachment can cause an undesired operation of an impedance due to load condition.

·????????Load encroachment uses load blinder characteristics for blocking overreaching of distance elements.

·????????For better load rejection, the traditional lenticular or elliptical shape characteristics can be used. But these characteristics reduces the fault resistance coverage(excludes the load from tripping characteristics).

Usman Hamid

Manager Contracts || Substation || HV Cables || Smart Metering || Smart Cities || MEP || Renewable

3 年

Amir R. how much overloading provision is allowed for load encroachment function which restrains the relay from tripping ?

Muhammad Sabtain

Senior Protection & Control Engineer @ Siemens Energy UK, MIET (UK)

3 年

I think that all zones of line protection must be mentioned and then load encroachment impedance or load blinders must be in between extreme two zones and restrain the relay to operate on overload condition But here question is that for how much time we can overload our transmission line and what would be the impact of transmission transformer

回复
Vamshi Krishna

Principal Consultant in TNEI, Manchester

3 年

Yes. It is because of enabling the load encroachment function in the relay which restrains the relay from operating.

Davron Sharipov

Project Manager. The Commonwealth of Independent States Project PV Solar power plants in Uzbekistan.

3 年

Karthikeyan Sandhanam An excellent article keep it up. It is very relevant for the upcoming Demand Side Response. I love it when someone lays out things in the simplest fashion. Thank you

回复

要查看或添加评论,请登录

Karthikeyan Sandhana Krishnan的更多文章

  • Transformer Tap Setting calculation details

    Transformer Tap Setting calculation details

    5 条评论
  • Voltage Transformer - 2

    Voltage Transformer - 2

    Inductive Voltage Transformer(IEC 61869-3) The standard values of rated output at a power factor of 0.8 lagging are:…

    1 条评论
  • Voltage Transformer - 1

    Voltage Transformer - 1

    A Voltage Transformer is mostly connected between phase and earth. The IEC standards covering the voltage transformers…

    4 条评论
  • Indication Lamp & Push Button Color

    Indication Lamp & Push Button Color

    Red color – Assigned for Emergency / Danger / Faulty / Stop Action Amber/Orange/Yellow Color – Warning / Abnormal /…

  • Current Transformer - 3

    Current Transformer - 3

    Protection Core Current Transformer As per IEC 61889-2: 1) Current Transformer – Composite Error Requirement · Class P…

  • Current Transformer - 2

    Current Transformer - 2

    Over Dimensioning Of Current Transformer: The over dimensioning factor of CT depends on 3 factors. They are 1.

    5 条评论
  • Current Transformer - 1

    Current Transformer - 1

    Function of Instrument Transformer: As meters and relay cannot be connected directly to high voltage and high current…

  • Carrier Aided Protection Scheme

    Carrier Aided Protection Scheme

    PUTT (Permissive Underreach Transfer Trip): Carrier Send = Zone 1 pickup Carrier Receive + Zone 2 Pickup =…

    3 条评论
  • Line Protection( Basics )

    Line Protection( Basics )

    Reach: It is the impedance of the transmission line upto which the distance relay protects the line from fault. ·…

    10 条评论

社区洞察

其他会员也浏览了