Section 12 in Madhya Pradesh Electricity Grid Code (Revision-II), 2019
12. Section 12
Contingency Planning12.1Introduction. - This section describes the steps in the recovery process to be followed by all Users in the event of State Transmission System or Regional System total or partial blackouts.12.2Objective. - The objective of this section is to define the responsibilities of all Users to achieve the fastest recovery in the event of a State Transmission System or Regional System blackout, taking into account essential loads, Generator capabilities and system constraints.12.3Contingency Planning Procedure12.3.1SLDC shall be prepared to face and efficiently handle the following two types of contingencies:(a)Partial system black out in the state due to multiple tripping of the transmission lines emanating from power stations/sub-station(b)Total black out in the state/region12.3.2In case of partial black out in the system/state, priority is to be given for early restoration of power station units, which are tripped. Start up power for the power station shall be extended through shortest possible line and within shortest possible time from adjoining sub-station/power station where the supply is available. Synchronising facility at all power stations and 400/220kV sub-station shall be available.12.3.3In case of total regional black out, SLDC In-charge shall co-ordinate and follow the instructions of WRLDC for early restoration of the entire grid. After total collapse, for each power station, to avoid damage to the turbine, survival power is required. To meet the survival power, the diesel generating (DG) sets of sufficient capacity shall be available at each power station. Start-up power to the thermal station shall be given by the hydel stations and interstate supply, if available. All possible efforts shall be made to extend the hydel supply to the thermal power stations through shortest transmission network so as to avoid high voltage problem due to low load condition. For safe and fast restoration of supply, STU shall formulate the proper sequence of operation for major generating units, lines, transformers and load within the state in consultations with WRPC. The sequence of operation, shall include closing/tripping of circuit breakers, isolators, on-load tap-changers etc. In emergency situations the licensee may approach to a near by captive power plant to get the start up power. The STU shall formulate the proper sequence of operations in this regard.12.3.4List of generating stations with black start facility, inter-State/inter- regional ties, synchronizing points and essential loads to be restored on priority, shall be prepared and be available with NLDC, RLDC and SLDC.12.4Restoration Procedure12.4.1The procedure for restoration of State Transmission System shall be prepared by the SLDC for the following contingency and shall be in conformity to the System Restoration Procedure of the Western Region prescribed under IEGC.(a)Total system black out(b)Partial System Blackout(c)Synchronisation of System Islands and System Split12.4.2The restoration process shall take into accounts the generator capabilities and the operational constraints of Regional and State Transmission System with the object of achieving normalcy in the shortest possible time. All Users must be aware of the steps to be taken during major Grid Disturbance and system restoration process.12.4.3The procedure will be reviewed, confirmed and/or revised once every subsequent year. Mock trial runs of the procedure for different sub-systems shall be carried out by the SLDC at least once every six months under intimation to the WRLDC. Diesel Generator sets for black start would be tested on weekly basis and test report shall be sent to WRLDC on quarterly basis under intimation to SLDC.12.5Special Considerations12.5.1During restoration process following State Transmission System or Regional system blackout conditions, normal standards of voltage and frequency shall not apply.12.5.2Distribution Companies with essential loads will separately identify non-essential components of such loads, which may be kept off during system contingencies. Distribution Companies shall draw up an appropriate schedule with corresponding load blocks in each case. The non-essential loads can be put on only when system normally is restored, as advised by SLDC.12.5.3All Users shall pay special attention in carrying out the procedures so that secondary collapse due to undue haste or inappropriate loading is avoided.12.5.4Despite the urgency of the situation, careful prompt and complete logging of all operations and operational messages shall be ensured by all Users to facilitate subsequent investigation into the incident and the efficiency of the restoration process. Such investigation shall be conducted promptly after the incident.12.5.5All communication channels required for restoration process shall be used for operational communication only, till grid normalcy is restored.
