ELECTRICAL SYSTEM ( HT ) PANEL 11KV FOR EQUIPMENTS AND SYSTEM (PART -I)- ABC OF THERMAL POWER

Till last dispatch basics electrical system discussed which are essential for the erection and commissioning of the Power system. Earthling rods and flats are laid at different places when civil works under progress. Riser are kept at different places to get it connected. Slowly it becomes like a grid. There value etc are precisely monitored time to time. After that main plant DC system are getting erected .As it was told no AC system will run without  the DC input.

Two more systems are coming after that one is HT ( 11kv/6.6 KV /3.3KV system ). It allows to distribute power in power plant as bulk and also the source running equipment like BFP , ID ,FD PA etc motors . Higher rating equipments are connected with HT ac voltage and this will reduce the cable size considerably and easy handle at site.

Here is brief description of panel in a 500 MW power station. There will be variation site to site but more or less these feeders will be there. This will give a good idea of number of HT panel to be commissioned. Viewers comments /value addition  will be appreciated.

11 KV Switchgear

Generally a few companies supplied these panels and they are BHEL . ABB , C&G ETC . these panels are installed in service bay near unit one side at an elevation of 8.5m .

1.         PLANT DETAILS :

       THIS SYSTEM CONSISTS OF  11 KV AND 3.3 KV HT SWITCHGEARS (UNIT SWITCH BOARD BA,BB,CA,CB FOR UNIT #1 AND UNIT #2 AND STATION SWITCH BOARD 0BA,OCA FOR 11 KV/3.3 KV  STANDBY SWITCHBOARD  SUPPLY IN CASE OF BOTH GENERATORS OUT OF SERVICE) .

MAKE: BHEL,BHOPAL

RATINGS VOLTAGE : 11 KV & 3.3 KV 3PHASE 50 HZ AC , CURRENT:2750 A

11 KV SWITCHGEARS

I.The 1BA Board consists of the following HT Panels :

1.Incomer Panel ( incomer from UT A )

2.PT PANELS ( line /feeder PT  and Bus PT )

3.         Tie breaker from standby switchboard (0BA)

4 .        OUTGOING FEEDERS    

            3240 KW Cooling Water Pumps 1 & 2

2450 KW Primary Air fan        A (Unit #1)

            16MVA Unit Aux. Transformer A

            16MVA Misc. service Transformer()

            2MVA  Unit service transformer A

            3MVA VFD transformer (ID Fan 1A Channel 1&2)

            1.25MVA Bunker area service transformer

            1.6 MVA ESP Service transformers

            1.25 MVA CHP transformer 1A

            0.75 MVA Track Hopper Service Transformer

            1.6MVA Fuel oil service transformer

            7.5 MVA Station  aux. Transformer.

            2 MVA Station Service Transformer

            6.3 MVA CHP Aux.

             5. Spare feeders

            a) 3240 KW Motor feeder

            b)2 MVA Transformer feeder

II.The 2BA Board consists of the following HT Panels :

1.         INCOMER PANEL

            Incomer Panel ( incomer from UT A ) (Unit #2)

2.         PT PANELS ( line /feeder PT  and Bus PT )

3.         Tie breaker from standby switchboard (0BA)

4.         OUTGOING FEEDERS    

            3240 KW Cooling Water Pump 4

            2450 KW Primary Air fan        A (Unit # 2)

16MVA Unit Aux. Transformer A

            16MVA Misc. service Transformer

            2MVA  Unit service transformer A

            3MVA VFD transformer (ID Fan 2A Channel 1&2)

            1.25MVA Bunker area service transformer

            1.6 MVA ESP Service transformers

            1.25 MVA CHP transformer 1B

            0.75 MVA Track Hopper Service Transformer

            1.6MVA Fuel oil service transformer

            7.5 MVA Station  aux. Transformer.

            2 MVA Station Service Transformer

            6.3 MVA CHP Aux.

            5.  Spare feeders

            3240 KW Motor feeder

            2 MVA Transformer feeder

III. The 1BB Board consists of the following HT Panels :

1.         INCOMER PANEL

            Incomer Panel ( incomer from UT B ) (Unit #1)

2.         PT PANELS ( line /feeder PT  and Bus PT )

3.        Tie breaker from standby switchboard (0BA)

4. OUTGOING FEEDERS    

            10000 KW MD BFP (Unit # 1)

            3240 KW Cooling Water Pump 3

            2450 KW Primary Air fanB (Unit # 1)

16MVA Unit Aux. Transformer B

            2MVA  Unit service transformer A

            3MVA VFD transformer (ID Fan 1B Channel 1&2)

            1.6 MVA ESP Service transformers

            1 MVA Switchyard Service Transformer

            2 MVA Ash Sys Compressor Plant Transformer

            1 MVA Ash Water Power House Service Transformer

            2 MVA Off Side Plant Service Transformer

            2 MVA WTP Area Service  Transformer

            2 MVA Station Service Transformer

            0.5 MVA Raw Water Pump House Service Transformer

            1.6 MVA Administration Building Service Transformer

5. Spare feeders

            2450 KW Motor feeder

            1 MVA Transformer feeder

IV.The 2BB Board consists of the following HT Panels :

1. INCOMER PANEL   

            Incomer Panel ( incomer from UT B )  (Unit #2)

2. PT PANELS ( line /feeder PT  and Bus PT )

3. Tie breaker from standby switchboard (0BA)

4. OUTGOING FEEDERS    

            10000 KW MD BFP (Unit # 2)

            3240 KW Cooling Water Pump 5

            2450 KW Primary Air fanB (Unit # 2)

16MVA Unit Aux. Transformer B

            2MVA  Unit service transformer A

            3MVA VFD transformer (ID Fan 2B Channel 1&2)

            1.6 MVA ESP Service transformer

            1 MVA Switchyard Service Transformer

            2 MVA Ash Sys Compressor Plant Transformer

            1 MVA Ash Water Power House Service Transformer

            2 MVA Off Side Plant Service Transformer

            2 MVA WTP Area Service  Transformer

            2 MVA Station Service Transformer

            0.5 MVA Raw Water Pump House Service Transformer

            1.6 MVA Administration Building Service Transformer

5. Spare feeders

            2450 KW Motor feeder

            1 MVA Transformer feeder

Above description is typical of coal based super thermal power station feeder list. There may be variation site to site and of uses. But this will given an idea of HT drives and transformer required for HT drives.

Recently i was visiting a super thermal power station and there HT panel erection is going on. Some other picture on this will be on next dispatch.

continued to pat -ii