24-12-2012, 05:53 PM
Grid Connectivity Standards,Grid standards
Grid Connectivity.ppt (Size: 388 KB / Downloads: 188)
Transmission system Planning & Design
i. The transmission licensee shall plan and design the inter state/ intra state transmission system based on the following
CEA “Manual on Transmission Planning Criteria: 1994”
CEA “Report of the Committee for Updating the Best Practices in Transmission System for the Country: 2002”.
Latest Issue of CBIP Manuals on: Layout of Substations, Transmission Towers
Grid code
State Grid code
The integrity of the regional grid is not affected under various operating conditions including stipulated system contingencies
all elements of the transmission system shall be designed taking into account the specified factors of safety in regard to electrical, mechanical and civil aspects in the respective standards
optimal system to be chosen after performing load flow, short circuit, stability studies of the various transmission alternative
The system designed shall not impinge on the rating of the substation equipment in any other sub station in the vicinity.
Overhead Transmission Lines
The transmission line proposed to be connected shall be comply with the following
Tower design shall be based on the technical standards for the construction of electrical lines specified by the authority under section 73(b) of the Act
Foundation design for the tower to be developed by the transmission licensee for various soil categories.
Use of multi circuit and narrow based towers wherever ROW constraints exist
Each type of tower to be type tested for mechanical strength
ii. Clearance from PTCC shall be obtained
EHV/HV Underground Cables
i. Cables proposed to be connected to the system, shall comply with the following
Shall be of XLPE type corresponding to IS 7098
Cable conductor to be of adequate size considering continuous current, short circuit current, voltage drop etc, & shall correspond to IS-8130
Cables to be provided with proper sheathing, armoring & screening
Prior permission from appropriate authority to be obtained for digging trenches, precautions to be taken
Route maps to be kept at Substation & markers shall be fixed to trace the cables
Road crossing to be carried out by providing Hume pipes or GI pipes
Jointing & termination to be carried out as per relevant standards
ii. Clearance from PTCC shall be obtained
Substations
Planning and design of substations to be based on the following
All EHV circuit breakers to be of SF6 type
Isolators to be pneumatic or motor operated
ICTs to be provided with OLTCs
Surge arrestors to be of metal oxide type (as per IEC 60099)
Control room to be extensible
All substation structures to be of lattice steel. Structures to conform to IEC 865, IS-875, IS-802, IS-800
Electrical, mechanical and civil designs to be standardised to the extent possible
Insulation coordination
For new connections, the CTU/ STU/ transmission licensee, shall inform the transmission users seeking connectivity, the BIL and important parameters of the equipment and ratings of the surge arresters in its system adjacent to the connection point.
The transmission users and licensees seeking connectivity shall furnish to the CTU/ STU, the BIL of the proposed system/ important items of the equipment and the rating of the surge arresters adjacent to the connection point
The CTU/ STU/ transmission licensee shall determine the ratings of the surge arresters to be installed at the connection point
Requisite insulation coordination to be done by the CTU/ STU/ transmission licensee.