• Members enter buy or sell bids of power for delivery on the next day.
• Bids can be entered for each 15 minutes block for 96-time blocks.
• Bidding session: 1000 hrs. - 1100 hrs.
• Type of bids can be entered as Single Bid, Block Bid, Linked Bid, Profile Block Bid, Minimum Qty. Block Bid.
• The bids entered during the bidding session can be modify or cancelled till end of bid call period

• At the end of the bidding session, the matching of bids for each 15 minutes time blocks shall be governed by the principle of Social Welfare Maximization.
• All purchase bids and sale offers will be aggregated in the unconstrained scenario. The aggregate supply and demand curves will be drawn on Price-Quantity axes. The intersection point of the two curves will give the market clearing price (MCP) and market clearing volume (MCV) corresponding to price and quantity of the intersection point.
• MCP and MCV will be determined for each block of 15 minutes for both segments i.e. GDAM, DAM & HPDAM.
• Selected members are intimated about their partially or fully executed bids and other trade related information.
• By 1145 hrs, combined transmission corridor required to fulfill successful transactions are sent to NLDC
• The example below illustrates price calculation. Assume the price tick as below:
  

Portfolio 1, 2,3, and 4 for the specific price tick has quoted quantity in MW as shown below:

Price (INR/MWh) 0 5000 5001 6000 6001 8000 8001 8499 8500 8501 9000 9001 10000 Portfolio 1 200 200 100 100 50 50 25 25 25 0 0 0 0 Portfolio 2 100 100 100 100 100 100 75 75 75 75 75 0 0 Portfolio 3 0 0 -50 -50 -50 -50 -50 -50 -50 -50 -50 -50 -50 Portfolio 4 0 0 0 0 -25 -25 -25 -25 -50 -100 -100 -100 -100

System will look for a solution where the net transaction is zero i.e. buy quantum is equal to the sell quantum.

Price (INR/MWh) 0 5000 5001 6000 6001 8000 8001 8499 8500 8501 9000 9001 10000 Total Buy (MW) 300 300 200 200 150 150 100 100 100 75 75 0 0 Total Sell (MW) 0 0 -50 -50 -75 -75 -75 -75 -100 -150 -150 -150 -150 Difference 300 300 150 150 75 75 25 25 0 -75 -75 -150 -150

In case similar block bids has been received, selection criteria shall be based on below priority:

• I. Price: Most favorable price shall have priority (Economic Dispatch).
• II. Volume: Block bid, which maximizes the market volume, is favored.
• III.Time: Block bids submitted earlier attracts priority.

Paradoxical rejection in Block Bids: System may reject a Block bid even though it would appear to be a valid bid for selection. This happens in a situation when inclusion of such a Block bid may result in the change in MCP at which the bid cannot be accepted.

• By 1215 Hrs, NLDC reverts with actual transmission corridor availability during all 15-minute time blocks across congestion prone bid areas.
• HPX process GDAM final matching based on corridor availability and then unselected orders (for which orders user selected OCF facility) shall be carried forward to DAM for ACP matching based on corridor availability. And then, the unselected orders (for which orders user selected OCF facility) shall be carried forward to HPDAM final matching(only for Buy Bids).

• Based on the transmission capacity intimated by NLDC, HPX recalculates area clearing price (ACP) and area clearing volume (ACV) for GDAM, DAM & HPDAM separately.
• ACP is used for the settlement of the contracts.
• Deviations from schedules are dealt under Deviation Settlement Mechanism regulations. The Regional Entities (those connected at ISTS networks) are governed by CERC regulations and Embedded Entities (those connected to state transmission or distribution network) are governed by respective State Commission’s regulations.

• Fund validation while bidding over PX.
• Obligation will be generated after final matching for Clearing and settlement purpose.
• Initial and additional margin fulfillment after trade
• Payin/Payout settlement as per HPX business rules

• Final Results and Application for scheduling of GDAM, DAM & HPDAM will be sent to NLDC collectively.
• NLDC sends the details of the schedule to respective RLDC/SLDCs.

• RLDCs /SLDCs incorporate Collective Transactions in their Daily schedule.
• A scheduled transaction is considered for deemed delivery.
• Deviations from schedules are dealt under Deviation Settlement Mechanism regulations. The Regional Entities (those connected at ISTS networks) are governed by CERC regulations and Embedded Entities (those connected to state transmission or distribution network) are governed by respective State Commission’s regulations.