DISTRIBUTED ENERGY RESOURCES : ISSUES AND CHALLENGES

Deeksha Sanwal 1 , Disha Gusain 1 , Leena G. 1 and Mohit Verma 1,2 . 1. Department of Electrical and Electronics Engineering, Manav Rachna International University, Faridabad, Haryana, India. 2. Accendere KMS-CL Educate Ltd., New Delhi, India. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History


ISSN: 2320-5407
Int. J. Adv. Res. 6(3), 1127-1132 1128 Bring sources closer to the loads contributes in reduction the heat losses and transmission cost. Existing grid allows one way communication whereas micro grids allow two ways communication as shown in Fig 1 and 2 respectively.  The DER system is capable enough to enhance the safety of the bulk power system by confining overcrowding, loop flows, high losses and cascading effects. Specifically, due to the decentralized nature, the distributed resources enhanced the considerable consistency of the system as a whole by making power supply less dependent on the bulk transmission network.
Some DER sources such as micro-turbines, fuel cells are easily controllable, while others (wind and solar energy) having highly unpredictable power output. This necessitates highly and flexible automated distribution systems with quick responses. Advantages Of Der:-As compared to the traditional sources, the DER sources are more advantageous in terms of several features such as flexibility, cost etc. Various advantages of DER sources over traditional sources are given in below table (Table-1).  Economics Of Der:-Cost is one of the most important factors when considering any product or its installation. However, the cost estimation of a DER technology is highly complex, as it includes the equipment (or capital) cost and labour cost along 1131 with other expenditures such as installing the equipment. The cost of generated electricity by the DER technology is also determined and compared with the current price of the existing power grid electricity. Table 3 gives a comparison of cost of various DER technologies Issues And Challenges In Der:-As the usability of the DER increases, the distribution grids have to itself bear the responsibility of the transmission systems. However, this entire system contains huge numbers of small generation units on the distribution grid, which leads to some technical challenges such as: a) Interconnection or integration with grid -The microgrid provides a benchmark between island and interconnected grid [8,9]. Installing micro grid in remote locations is expensive than in normal location as remote location such as island and hilly areas which are far away from utility where transmission lines are unable to reach. At the starting independently a micro grid in island (working separately from the grid), the current producing by the system having highly fluctuations, which causes significant deviations in system parameters such as voltage and frequency, and necessitate the protection of the generator for to be tripped offline during start-up [10], b) Fixing of tariff-Traditional generation sources tariff is fixed in a particular way considering the initial cost as well as running cost. Individual micro grid installed at different locations would reduce the consumption of energy from the traditional grid which leads to loss for them. Hence a different tariff needs to be found out to balance the traditional grid and DER.
(c)The flow imposed by DER in between independent entities is bi-directional; this cannot be handled by today's existing distribution systems. Some modifications in the existing grid need to be done to accommodate the DER sources. With the increasing need of energy, a micro grid (DER) should be able to fulfill local increased load and robust communication between management system and individual source of energy.
(d) Protection-It is essential to redesign the system in order to familiarize the associated distributed generators with the distribution system. This will enhance the necessity of the distributed intelligence systems and its deeply relying on multi-party communications [3]. Hence one of the most significant threats on DER system is its safety [11].
(e) Balancing and stability of grid-The fundamental problem is that system becomes more complex and fails to control. Since there are number of microgrids or aggregated power sources in a system, it is very complex to handle the control among all the power sources. A solution to overcome this complexity is required. The DER system need to respond to all acute events separately using local information i.e. voltage, frequency and current [4] and hence should provide balance and stability of grid.