Surinder Kumar Negi, Managing Director, Gujarat Energy Transmission Corporation (GETCO) says that the company has already enhanced transmission lines with an investment of Rs 4,350 crore during the first two years of the 12th Plan period.
Your company has tied up with IIT-Bombay to develop a Dynamic Stability Analysis for ensuring grid stability; can you give us more details on this initiative?
Phasor Measurement Unit (PMU) is a state-of-the-art grid parameter capturing and transmitting device, calibrated in milliseconds. It is a superior technology over the SCADA system. It is important that these grid parameter data are analysed for the status of grid and provide pre-warning /alarm and anticipated disturbances during real time operations of the grid. To do so, we need to develop analytics which are supported by core engine and software. We are installing the Phasor Measurement Unit at 29 strategic locations of Gujarat transmission network with Phasor Data Concentrator (PDC) at SLDC, Vadodara and IIT-Bombay.
Hybrid State Estimator: When PMU data is used in the state estimator, the accuracy improves considerably. We plan to develop State estimator with the available PMU data initially, remaining data will be used from the existing system.
The State estimator will give output of the State in graphical and tabular form with alarm for violations with possible remedies.
Online Power System Oscillation Mode Identification: The power system oscillations are seen in most of the measured variables like bus voltage, transmission line currents and frequency etc. The aim of this module is to identify oscillation modes and analyse them for severity for ambient and event scenarios.
Dynamic Security Assessment with voltage stability: GETCO has planned to provide DSA for system operation, which identifies the system capability against any contingency, possibility of contingency, and possible remedies. The major advantage is the availability of these security tools in real time with a dynamically changing system.
GETCO has registered 60 per cent growth in setting up transmission networks in the 220 kV voltage segment over the past decade. What are the reasons for this robust performance?
In a State transmission utility (STU), the sub-transmission system at 220 kV, 132 kV and 66 kV has to be robust with penetration in every nook and corner of the State. When the bulk power is received through main-transmission network of 400 kV, it is cost effective to have 220 kV system matching with the power requirement of load centres. In a State with spread over load centres, it is obvious to have more of a 220 kV transmission network.
How much do you plan to invest in transmission lines during the 12th Five-Year Plan? Which voltage segments will you focus on for this period?
We have planned to invest around Rs 10,000 crores in network development during the 12th Five-Year Plan by adding more than 450 substations and 10,000 ckm of transmission lines. In the first two years of the 12th FYP, we have enhanced transmission capacity by adding 200 substations and 5,187 ckm of transmission lines with a total investment of about Rs 4,350 crore.
As such, network development is purely on the basis of load growth of particular location (urbanisation), industrial pockets, metro and infrastructure projects, therefore, it is very hard to identify a particular voltage class to focus on and hence transmission system at main and sub-transmission level shall be balanced between these two as per system study output.
Have all the issues pertaining to differential compensation in Right of Way (RoW) for transmission lines been solved?
Right of Way (RoW) for transmission lines remains a sensitive issue looking into the devaluation of owner's land. However, transmission utilities are quite liberal in the matter of compensation. It may not be to the satisfaction of the affected party, but a procedure has been laid down to obtain the consent or seek the intervention of local authorities. How has your plan to release optical fibre network to telecom operators progressed? The optical fibre network project is still in a stage of infancy. We have planned to lay a large quantum of OPGW before releasing the same to telecom operators. Moreover, we would first like our discoms and State Government to make full use of it, especially for the rural areas. GETCO has disallowed a few industrial units from buying cheap power in open access from outside Gujarat. Why has this issue cropped up? SLDC has restricted short term open access (STOA) only in the South Gujarat area, looking into grid constraints and security of the grid in real time operation, when demand had gone up. STOA is the last priority when there is question of grid security without having any effect on Long Term Open Access consumers. We have explained the constraints in the upstream network to all the stakeholders in the Southern Gujarat intrastate network in the absence of huge quantum of costly fuel (gas) generation at 220 kV and 132 kV voltage level. The entire topology of the network has been in operation with these gas generation plants and now the sudden absence will have to be fed from the upstream network through adequate 400/ 220/ 66 kV transformation capacity. Majority of STOA power comes through interstate CTU network and to serve these STOA consumers in South Gujarat, there is a need of transformation capacity in the network which cannot be created in advance to exclusively promote STOA. One of the prime conditions of STOA is that no new network shall be created and it has to serve within the available margin. For Gujarat SLDC, grid security is a prime objective for 24x7 power supply and therefore, rationale behind restriction only in South Gujarat area is according to the regulation. GETCO has been awarded the "Gold Shield" for the 220 kV Charanka Substation in the category of early completion of power transmission projects for the year 2011-12 and the 'Silver Shield' for the 220 kV Bhachau (Vondh) substation in the category of early completion of power transmission projects for the year 2012-13. What are the biggest reasons for your early completion of these power transmission projects? Our project cycle in GETCO starts from conceptualisation to closing of the project. This project cycle is further divided into milestones like management approval, budget, land acquisition, contract packages, award of contract and execution. All these milestones are structured in a project planning document and MS project. The key point for a successful project is control and monitoring, which is done through natural process of Plan-Do-Check-Act (PDCA) cycle as guided in our ISO documentation. There is no exclusive big reason for the early completion of 220 kV Charanka and Bhachau, but for the adoption of the project cycle in every project of GETCO. Devarajan Mahadevan