Modelling determines the Optimum Generation and Distribution Voltage for planting a Medium Voltage (MV) Prime Powered Diesel Generators to supply entire yard for its long term power requirement. PowerQ was contracted as consultant to perform feasibility and design studies. PowerQ had created a model of power system which included 10 no. Generators and 28 no. Substations. Ultimately, the system was required to operate in parallel with 20kV local grid.
The challenge was:
If lower voltage was selected then the grid or distribution need step-up transformer. PowerQ modelled the system using PTW software.
Following options were considered:
Voltage drop, load flow and short circuit studies were carried out for various options. Cost analysis was performed for the various options.
The general approach for this study includes a discussion of the following key issues related to the installation of the generators and required auxiliary equipment:
The cost involved is the supply cost of MV generation and system installed which assumes no contingency, operational fuel cost and all associated engineering costs for the project. The majority of the cost for each option was the capital cost to install the generator permanently as generator's cost is governed by speed and voltage for same capacity. There was significant component of fuel cost based on the option exercised that was considered for decision-making.
It was found that 20kV distribution system was very costly, while 400V generator was cost-effective than 6.6kV generator.
With the basis of our knowledge on Voltage Drop Calculation and Life Cycle Cost Analysis Study, it was found that option 3 was less costly by more than USD1million. Based on data such as voltage drop, fuel consumption and cost of switchgear and cables at various voltages, as recommended by PowerQ the company adopted Option 3 for the project.