Power Supply Restoration (Hudhud Cyclone) - Part 6 1. The cyclone has devastated everything and is going to take time for revival. Its true to some extent but after the initial derbies are cleared and dumped in alternate dumping grounds, this may not hold good. Section of the administration will be trying to restore power supply and the other sections will be involved in the restoration of the water supply network and supply of essential items. Transport and communication network should be back on line with in 5 days and should be fully functional from 7th day onwards. Any major damage to road and rail bridges may take time for full restoration but movement can be facilitated with the help of heavy machinery of armed forces and NDRF. Once rail and road network starts operating, there will be no dearth of essential supplies in the entire disaster zone. An experienced and highly proactive disaster management team with supported from the apex level can advance normalcy by a day or two. This will help the people to start forgetting the negative effect that the cyclone to some extent. Remember, every challenge that we face without the problem being created by ourselves, is nothing but a opportunity for us to learn how to survive and deliver results under most difficult situations. 2. Coordinated effort must be initiated for power supply restoration. Due care must be taken to avoid any electrolution in the process of power supply restoration. Section wise responsibly/accountability must be ensured and all sections must be isolated from each other electrically to avoid any danger and inter connectivity should be done under the command of high ranking electrical engineers, section wise. Only skilled and authorized persons should be allowed to carryout the restoration under central command. More precaution has to be taken after the the initial phase of power charging. The electrical network restoration work must be divided into five levels. a. Grid level. b. Sector level HT. c. Sector level LT. d. Area level. e. Individual houses. 3. Non linear approach must be followed for electricity restoration with dedicated teams working in five different areas as mentioned above. This will help to simultaneously restore powers supply to larger areas, once city grids are made available with power. Generally it should take around 7 to 8 days to fix the HT towers with the help of temporary structures. Restoration of electricity network needs erection of poles, straightening of poles, relaying of cables,replacement of transformers etc. Every component of the system such as mounting brackets,insulators and holding clamps and any other items must be made available in ready to install conditions as during normal time power supply is required to make these items ready for installation. Due care must be taken to provide portable gen sets and gas welding/cutting items to restoration teams to make these factory dispatched items suitable for field use right away 4. Sufficient new cables both HT and LT must be supplied as part of the restoration process. Service wires for individual houses also should be provided by the distribution companies as an one time measure. The users can be charged a nominal amount after the restoration process is over for the same. Once supply is restored in an area, mobile teams must be deployed to charge individual houses and mobile team augmentations must be done based on field requirements. Manpower should not be an issue after 7 days of the cyclone, as only few square kilometers are affected as compared to a few lakh square kilometer area of the state with larger quantity of people available at the disposal of the state Govt. 5. The area and individual house restoration must be supervised by officers of one step higher than that used in normal situations. In addition to that radio broadcast must be done to request people to launch complaint at a central location to avoided any infield inefficiency or local factor problems. In case restoration is delayed in some cases a central mobile team must be sent to the field for rectification and identifying on field requirements to augment the mobile teams. 6. It is preferable to relay new Aerial Bunch (AB) cables in the effected areas and dump the old aluminum open wire cables as they will speed up the restoration work and will be futuristic for next ten years and will prevent theft of electricity in long term. Further every part of the discarded electricity network has a disposal value allowing cost recovery to up to 50% or more. So due care must be taken by a dedicated team to manage the discarded electrical inventory to prevent theft by both insiders and outsiders. Police administration must be strictly advised to keep tracking potential buyers of disposed items. 7. During restoration pole spacing must be kept large for speed of work and later intermediate poles can be erected to straighten the AB cables/HT cables. The initial pole span must be decided based on the future planning of intermediate poles. 8. Power supply restoration should be commanded by high ranking Electrical engineers present at restoration command center and current managerial staff must be withdrawn till normalcy is restored. This is a must to avoid inefficiency and negative bias. Further restoration needs informed technical decision making necessitating a technical subject expert at the helm of the affairs. 9. The perception regarding power supply restoration time period after a cyclone is a relative issue and the current situation should not be compared with any other cyclone happened at any part of the world. The most difficult part of the supply restoration is erection of gigantic HV distribution towers so that power can be fed to the city supply distribution points. In case, power is made available through multiple routes to the city, effort must be made to restore the lowest damaged route with a dedicated and professional team guided by on site and off site experts to mitigate any on field challenge arising in the restoration process. Generally temporary towers can reach to sites once the road route is clear. Erection of portable towers for HV lines (132KV or higher) is a skilled job,executed by the Grid Corporations or their authorized contractors and a single team can erect a tower in less than two days. Normally during cyclone, all towers do not fall as once the HT line loses its line tension due to one breakage the other towers do not tumble on their own. But this is totally an unpredictable condition. Under these conditions, Grid restoration work should be over by 7th day and power should reach to the city supply distribution points after that. This needs deployment of multiple teams in strategic routes so that alternate power line routes are created with minimum resources. In case underground power supply network is available, power should be available right at the city distribution points within 48 hours of the cyclone. 10. Time should not be wasted in the initial 7 days waiting for grid to be restored. Power supply restoration is a non liner activity with dedicated teams working with different jurisdictions. In case of a severe damage by the cyclone, it is better to relay the power supply network than correcting the existing network. Insulated Aerial Bunch (AB) cables can be used to relay the distribution network in 440V level. As part of the cyclone preparation Govt might have reserved sufficient number of transformers and the same should start flowing into the disaster affected areas once the road network is open for movement. After initial damage assessment is over, more transformers from the adjourning areas and states must be requisitioned by the Govt. agencies. All these activities needs State Guarantee for payment, then only materiel can flow right into the disaster zone right from the factory gates. Apex level decision making authorities must facilitate this guarantee so that the restoration workers do not sit idle in the field due lake of materials. The temporary HV towers can not be erected in the original tower positions as they are temporary and has to be removed after a month or two by recasting permanent towers in the original positions. Hence District administration must facilitate availability of space in and around the existing towers without any resistance from the local persons on whose land the temporary towers will be erected. This may need compensation guarantee from the state in case farm productivity is effected in the selected area. Later permanent towers can be erected and these temporary structures has to be removed. Transformers in all important areas must be replaced beforehand as during absence of grid power, scope for knowing the serviceability of the existing transformers can not be guaranteed and power may not be available to users after grid power is restored. The removed transformers can be checked for their serviceability and can be connected at other places, as there will a continuous need of transformer in the disaster area. Generally open wire public distribution networks get entangled during the cyclone and with the first phase power supply restoration, the transformer fuses start blowing. So try to remove the jumbled electrical wires and where existing network is used with corrective measures, the fuse blown occurrence will be maximum. Deploy mobile teams to correct such small faults effecting large section of people. Always work non linearly during restoration with few crisis managers interlinking section works so that particular areas can be served once grid power is restored. In case the CBs do not stand due section problems keep distrusted sections out of circuit and deploy man power for correction and connection to main CB. Generally restoration workers inherently tend to be inefficient and manifest irritating behavior after the initial phase of supply is made available to people. A close guard must be maintained for non occurrence of such incidents through carrot and stick policy. Additional workers must be brought in at this time as replacement or as supervisory reinforcements to the existing teams. Erection of new poles needs mounting brackets and insulators. When the poles are delivered, they do not have the mounting arrangements. So do take special precaution to make necessary holes in the brackets and poles so that poles can be erected and later brackets can be mounted to them using nut and bolts. Due lack of power supply it is difficult to make holes in the field and without mounting holes the poles can not be erected. So arrange gas welding/cutting machines in mobile vehicles and make necessary holes in the poles and mounting brackets before hand either at central locations or at the site of erection. During Phailin cyclone, some contractors used innovative way of erecting poles using JCB machines to exert vertical pressure and press the poles right into the ground vertically in areas where no hard rock is found up to 3 meters. This process is speedy and one single team of 6 people can erects lots of poles in a single day. Take precautions as the job is a very skilled one with some kind of risk while the poles are shifted from horizontal to vertical positions using wrench wires due to a high unbalance holding position creating difficulties in balancing the poles. The only need is a small arrangement for putting vertical pressure by holding the pole at a reasonable high point and an extra hole in the pole for using the wrench wire. 11. After dedicated teams give clearance for normalization, start charging the lines right from the heart of the city and keep going outward. Generally public resent starts after power supply is restored to the first areas as there will be a delay of approximately 96 hours to make power available to larger section of the society. Reduce this time gape by employing more workers and manage this resent with sincere work as people generally tend to understand the real difficulties but agitate only when small works delayed due insincere persons. Always use dedicated mobile teams working round the clock under high quality supervisors for shorting out individual house issues. The mobile teams must carry service wires which will be required most so that the individual customers are not inconvenienced. 12. Power rationing is bound to happen till all the HT sections connected to the city grid are restored which is going to take minimum 3 weeks. Do not use heavy appliances and always try to restrict your household load to a near constant value through alternate switch on and off of appliance to keep the grid frequency stable. 13. Big generators must be sent to pump stations with mobile vehicles. Such generators are available in plenty with event management groups as they are used to manage events with their own power supply arrangements. Keep rotating the generators will skilled staff for maximum positive impact in water distribution network. When power supply is not available some pumps do not work resulting in low pressure in the pipe line. So always keep the underground reserves below the supply point so as to allow the dripping of water at low pressure so that the tanks can be filled slowly by the dripping of water. However water needs to be pumped regularly at the pumping station to create some kind of pressure in the water supply network. Generally people tend to fill their underground reservoirs from external tankers to an a level, where this dripping water stops flowing into the tanks. 14. Continuous supply of bottled water must be ensured for a reasonable period of time under strict monitoring of a dedicated high level team. Portable mobile water purifiers must be made available and installed at different places. 15. The command center should be assisted by a dedicated team for event logging in real time and restoration data generation. Fundamental event logging should be done so as to analyze the effectiveness of the restoration process at a later stage. Regards Bighnaraj Panigrahi
Posted on: Sun, 19 Oct 2014 16:46:47 +0000
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