Section 15 in Tamil Nadu Electricity Regulatory Commission Tamil Nadu Electricity Distribution Code
15.
The procedures and practices to be followed by the Licensees and consumers whose electric lines and electrical plants are connected to the Licensee's distribution system for safe and efficient operation of then-respective systems are -,(1)Demand Estimation: The Licensee shall provide to the SLDC / SSLDC, its projection of demand on a year ahead, month ahead and day ahead basis. The time frames for such submission, as set out in the TNEGC shall be adhered to by the Licensee. The SLDC or SSLDC shall be the agency to receive the details from the licensees or issue directions to the Licensees as the case may be in line with the requirements prescribed in this chapter on Operational Guidelines and as per the provisions of the relevant Code. On demand, the [consumers concerned] [Substituted for the expression 'concerned consumer' as per Commission's Notification No.TNERC/DC/8-8 dated 8.2.2008 (w.e.f. 27.2.2008)] shall furnish these data to the Licensees. The Licensee shall estimate its hourly and daily demand on the basis of relevant load curves drawn on a day ahead basis, subject to modification depending upon information received from any specific consumer or caused by any untoward incident/contingency.(2)Scheduled Shutdown Programs: The Licensee shall furnish the proposed (planned) outage (scheduled shutdown) programs to the STU/ SLDC as specified in TNEGC. Planned outage programs shall furnish clearly the details of the electric lines/cables and the equipments of the distribution system that will be taken out of service, and other details of the planned interruption namely the date, duration and quantum of load that may be limited/restricted at any interconnection during this planned interruption.(3)Contingency Planning: The contingencies in the distribution system are mainly due to:(a)Total or partial blackout of intra transmission or inter transmission network. (Loss of generating sources)(b)[Failure of network components like Breakers, Power Transformers, Current Transformers, Potential Transformers and lines in the transmission system. [[Substituted as per Commission's Notification No. TNERC/DC/8-8 dated 8.2.2008 (w.e.f. 27.2.2008) which before substitution stood as under:'b. Failure of network components like breakers, lines and UG cables in the transmission system, c. Breakdown of components in the distribution system']](c)Breakdown of components like Distribution Transformers, lines, etc. in the distribution system].The procedure to be followed during such contingencies for the restoration of supply is detailed in the sections to follow(4)Intra / Inter Transmission System outage: In regard to the restoration of supply during the total black out at any point of interconnection, the Licensee shall abide by the black start procedures framed by the STU / SLDC. Likewise, the Licensee shall follow the guidelines provided by the STU during the outage of the apparatus or lines/cables in the above networks. The licensees may also follow an approved Demand Side Management, Load shedding, rolling blackouts and other measures.(5)Distribution System Outage: The interruption of the power supply to any part of the distribution system lasting more than an hour, due to the breakdown of any part of the distribution system/its components, may be termed as distribution system failure and the Licensee shall evolve a suitable supply restoration procedure for such distribution system failures under intimation to the Commission.(6)Demand Management / Load Shedding: On getting directions from the SLDC rolling blackouts for short duration shall be carried out by the Licensees to maintain the load generation balance and security of the network. This may also be necessary due to the loss of any circuit, equipment or any other operational contingency that may occur in their Distribution Networks also. The Licensee shall estimate the loads that may be shed in discrete blocks at each interconnection point after consultation with the consumers if possible and submit the same to the SLDC. The consumers shall cooperate with the Licensee in this regard. The Licensee shall work out the modalities of the load shedding. A detailed procedure shall also be furnished to the SLDC and other officials in charge of the downstream substations of the Licensee, where such load shedding / rolling blackout are to be carried out. When provisions are available for the automatic load shedding with the aid of under frequency relays, the circuits involved and the quantum of load to be shed shall be intimated to the SLDC and [officials] [Substituted for the expression 'officials persons ' as per Commission's Notification No. TNERC/DC/8-8 dated 8.2.2008 (w.e.f. 27.2.2008)] in charge of downstream substations of the Licensee. The settings adopted for the UF relays shall also be furnished. If any constraint or bottleneck in the transmission system and/or distribution system, warrants rotational load shedding then it shall be resorted to by the Licensees in their distribution system. On such occasions, the public shall be promptly informed of such arrangements through the media. [Consumers] [Substituted for the expression 'Large consumers' as per Commission's Notification No. TNERC[DC/8-8 dated 8.2.2008 (w.e.f. 27.2.2008)] with [contracted demand] [Substituted for the expression 'contract demands' as per Commission's Notification No. TNERC/DC/8-8 dated 8.2.2008 (w.e.f. 27.2.2008)] of 1 MW and above and essential services such as hospital, public water works etc, shall be notified through telephone/ fax/ e-mail or any other communication systems.
