Microgrid as a Cost-Effective Alternative for Rural Network Underground Cabling for Adequate Reliability

Abstract

Microgrids can be used for securing power supply during network outages. Underground 42 storage system (BESS) usage on the frequency regulation market.43 Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 25According to [9] underground cabling of the network is an effective way for distribution system 44 operators (DSOs) to increase the reliability of power supply. However, underground cabling is 45 expensive. 46Today, farming is highly automated and electricity dependent [10] and even short power 47 interruptions are very detrimental. Farming is an energy intensive industry [11], and thus farmers 48 value reliability of electricity supply more than most of the other customer groups. 49Farms are located naturally in rural areas, possibly on the long distribution network radial 50 branches with low electricity customer density. The majority of farmers have back-up generators (e.g. 51[11]). Farmers having own power production to cover a portion of their electricity need is gaining 52 popularity. 53Several recent studies have focused on microgrid islanded mode operation, microgrid energy 54 management system, and power supply adequacy and forecast, e.g. [12][13][14]. Ref.[12] assessed power 55 supply capability in islanded mode operation within a couple of hours by using a simulation time 56 step of maximum 1 minute. Electro-technical aspects of an unexpected microgrid islanded operation 57 were also analyzed in [14] while considering optimal energy management of the microgrid and 58 anticipating an outage at any hour. Grid-connected microgrid economic operating strategy was 59 proposed in [15] to minimize the operating cost for the operating period of 24 hours-ahead. 60Characteristics of, e.g. the Finnish rural medium voltage (MV) networks are long distances and 61 low loads, and thus, underground cabling to increase reliability is not an economical option as-is for 62 the distribution network development. However, the legislation steers towards underground cabling 63 and cabling is incentivized by the regulation framework. 64 Ref. [16] posed a question, on which reliability indices the network development actions actually 65 should be based on, optimizing the number of faults, duration of faults, outages cost, or yet on some 66 other index. The indices in several Finnish studies considering the economics of cabling and 67 increasing reliability of power supply, are based on the results and data of a study from 2005, and the 68 regulation model framework, e.g., [16-19]. The studies evaluate the DSO investment profitability 69 only compared to the outage costs (or cost of energy not supplied, CENS). The customer-side and 70 possible co-operative technical and shared economic alternatives have not been considered. 71Studies have shown other alternatives' feasibility potential instead of underground cabling, e.g., 72BESS as back-up to cope with short interruptions up to a couple of hours, [19,20]. BESS sizing methods 73 in different microgrid application have been reviewed in [21], and [22] presented an a...

Reliability Assessment in Rural Distribution Systems With Microgrids: A Computational- Based Approach

“…Indeed, the effect on the quality of an RDS has been analyzed when microgeneration PV are introduced [28], and the effect on reliability when MGs are introduced in the RDS was evaluated from the sustainability point of view while considering social and cultural characteristics [29], [30]. Furthermore, MGs were compared to underground networks from cost point of view (i.e., profitability), showing that the former could be a more economical option [31], [32]. Likewise, energy management strategies have been discussed in RDS with MGs [33].…”