DOCUMENT COVER SHEETDirect Stroke Lightning Protection Calculation 400 / 220 / 33kV Indrapuram Substation 0 27.11.12 Rev. Date Description PREPARED BY Checked By Approved By S-3, 2nd Floor, Western Uttar Pradesh Power Aditya Mega Mall, Indirapuram, Transmission Corporation Limited Ghaziabad 201010, 7th floor Tower c Building No. Megha Engineering and Infrastructure 10 DLF Cyber city phase-II Gurgaon India Limited PROJECT : 765/400 kV Intra - State Transmission Project. NAME DATE DOCUMENT STATUS DOCUMENT TITLE SHEET SIZE PREPARED VIK 27.11.12 For Direct Stroke Lightning A4 BY Approval Protection Calculation CHECKED For Construction BY APPROVED As Built DOCUMENT NO. NO. OF SHEETS BY COVER + 06 400/220/33kV Indrapuram Direct stroke lightning protection Substation Calculations Substation Name Document Name Document No. TABLE OF CONTENTS CLAUSE NO. DESCRIPTION SHEET NO. 1.0 PURPOSE 2 2.0 CODES & STANDARDS 2 3.0 SIZING CRITERIA 2 4.0 FORMULAE USED FOR CALCULATIONS 3 5.0 CALCULATION 4 6.0 CONCLUSION 6 Sheet No. 1 of 6 400/220/33 KV Direct stroke lightning protection Indrapuram Substation Calculations Substation Name Document Name Document No. 1.0 PURPOSE: The purpose of this calculation is to determine the height of Lightning Masts for 400/220/33 kV Indrapuram Substation. 2.0 CODES & STANDARDS: a) High Voltage Engineering by " Prof.Razevig" 3.0 SIZING CRITERIA: 3.1 The height of Lightning Masts depend on the a) Height of the equipment to be protected. b) Area to be protected. 3.2 Data for 400KV Switchyard: a) Height of Lightning mast h 40 m b) Height of the livepart to be protected: hx 10 m All the heights has taken from the plinth level. 3.2 Data for 220KV Switchyard: a) Height of Lightning mast h 40 m b) Height of the livepart to be protected: hx 6m All the heights has taken from the plinth level. 3.2 Data for 33KV Switchyard: a) Height of Lightning mast h 40 m b) Height of the livepart to be protected: hx 4m All the heights has taken from the plinth level. SHEET NO. 2 OF 6 400/220/33 KV Direct stroke lightning protection Indrapuram Substation Calculations Substation Name Document Name Document No. 4.0 Formulae Used: A Protective radius (rx) : æ ç h ö÷ rx = 1.5h ´ çç1 - x ÷´P m ÷ 1 If , hx <= (2/3)h and h > 30m:- ç ç 0.8h ÷÷ø è æ ç h ö÷ rx = 1.5h ´ çç1 - x ÷ m ÷ 2 If , hx <= (2/3)h and h <= 30m:- ç ç 0.8h ÷÷ø è 3 Co-efficient for the Lightning Mast Height P 5.5/ h m 4 Allowable distance between two LMs S 7 x ha x P m m 5 Allowable diagonal distance between two LMs D 8 x ha x P m m Where ha= h - hx m B Midway point protective Height (ho) and Midway Point Protective Distance (bx) æ S ö h0 = h - ç ÷ m 1 è 7´ Pø æ hx ö 2 If hx < (2/3)ho and ho > 30 m :- bx = 1.5ho ´ çç1 - ÷÷ ´ P m è 0.8ho ø æ hx ö bx = 1.5ho ´ çç1 - ÷÷ 3 If hx < (2/3)ho and ho < 30 m :- è 0.8ho ø m æ h ö bx = 0.75ho ´ çç1 - x ÷÷ 4 If hx > (2/3)ho and ho < 30 m :- m è ho ø SHEET NO. 3 OF 6 400/220/33 KV Direct stroke lightning protection Indrapuram Substation Calculations Substation Name Document Name Document No. 5.0 Calculation a) For LM1 Height of the LM h 40 m Height to be protected hx 10 m æ ç h ö÷ rx = 1.5h ´ çç1 - x ÷´P m Protective radius ÷ ç ç è 0.8h ÷÷ø P = 5.5 /h 5.5/ 0.870 æ ç h ö÷ rx = 1.5h ´ çç1 - x ÷´P m ÷ Protective radius ç ç 0.8h ÷÷ø è = 1.5 X 40((1-(10/0.8 x 40))x0.870 35.8875 m Hence protection area of LM1 covers the 400 kV Substation area which have to be protected. b) For LM2 & LM3 Height of the LM h 40 m Height to be protected hx 6 m æ ç h ö÷ rx = 1.5h ´ çç1 - x ÷´P m Protective radius ÷ ç ç è 0.8h ÷÷ø P = 5.5 /h 5.5/ 0.870 SHEET NO. 4 OF 6 400/220/33 KV Direct stroke lightning protection Indrapuram Substation Calculations Substation Name Document Name Document No. æ ç h ö÷ rx = 1.5h ´ çç1 - x ÷´P m ÷ Protective radius ç ç 0.8h ÷÷ø è = 1.5 X 40((1-(6/0.8 x 40))x0.870 42.4125 m Hence protection area of LM1 & LM2 covers the 220 kV Substation area which have to be protected. c) For LM4 Height of the LM h 40 m Height to be protected hx 5 m æ ç h ö÷ rx = 1.5h ´ çç1 - x ÷´P m Protective radius ÷ ç ç è 0.8h ÷÷ø P = 5.5 /h 5.5/ 0.870 æ ç h ö÷ rx = 1.5h ´ çç1 - x ÷´P m ÷ Protective radius ç ç 0.8h ÷÷ø è = 1.5 X 40((1-(5/0.8 x 40))x0.870 44.04375 m Hence protection area of LM4 covers the 33 kV Substation area which have to be protected. SHEET NO. 5 OF 6 400/220/33 KV Direct stroke lightning protection Indrapuram Substation Calculations Substation Name Document Name Document No. Table Height of LM Height of the equipment Radius of LM S.No. LM Protection area (m) to be protected.(m) (m) 1 LM1 40 10 35.8875 400 kV Switchyard area 2 LM2 40 6 42.4125 220 kV Switchyard area 3 LM3 40 6 42.4125 220 kV Switchyard area 4 LM4 40 5 44.04375 33 kV Switchyard area Conclusion Hence from the above calculated protection area of LM1,LM2,LM3 and LM4 we can protect the indrapuram switch yard area from the direct lightning. SHEET NO. 6 OF 6