In this chapter, the author presents the operation and power management of the hydrogen storage-based smart DC microgrid (DCMG). In this microgrid, several renewable distributed generations (DGs) such as wind turbine, solar photovoltaic system, solid oxide fuel cell (SOFC), and battery energy storage system are interconnected together and to the various DC and AC loads to form a ring-type low voltage distribution network. An additional storage as Hydrogen storage system has been connected to the dc microgrid for balancing the power at all times in the DCMG, under islanded mode operation, for all practical cases. An architecture of the hydrogen storage-based DC microgrid is suggested mainly for the remote rural area. For the regeneration of the electricity from the stored hydrogen, a SOFC DG system is also used in the proposed DCMG. A control technique is also developed for the operation of the hydrogen storage-based DCMG. The proposed DCMG system provides a reliable and high-quality power supply and will supply the power to all loads (both DC and AC) simultaneously.
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For under-developed and developing countries, the remote rural areas may not have access to the electric power supply from the main grid. The Renewable Energy Sources (RESs), such as Wind Turbine (WT), solar Photovoltaic (PV), and fuel cells Distributed Generations (DGs) are available in the range of 1kW-10MW, which play an important role for the remote rural areas, discussed by Kumars (2014). During the last few years, the RESs are being fast developed, and attracted increased interests of the researchers and utilities due to various environmental, economical, and technical advantages offered by them, presented by Kumars (2015) and Xu (2011). Due to having the intermittent nature of the renewable sources, the direct connection of the renewable sources to the main grid (if it is available in the remote area) would create several problems such as; voltage fluctuations, frequency variation, and protection and stability issues, discussed by Vidal (2013), Wang (2012), Kumars (2015), and Kumar (2020). However, the utility grid may not be available in the remote rural areas. Therefore, the microgrid, which can be AC or DC, provides the facility for the connections of various renewable DGs and Energy Storage Systems (ESSs), discussed by Chen (2012), Aggarwal (2016), and Kumars (2021). The microgrid also provides an opportunity of electrification of remote rural areas, where the grid is not available. The DC Microgrid (DCMG) offers several advantages over ac microgrid as following: better reliability, ease control of each DG by controlling as only DCMG voltage, higher efficiency due to lower losses, no synchronization required for interconnecting many DGs, high power quality, and better controllability due to absence of reactive power, phase and frequency control, discussed by Kumars (2012), Radwan (2012), and Balog (2012).
The work of Kumars (2012) discusses that the Pulse Width Modulation (PWM) based Voltage Source Converters (VSCs) provide several functions as; maintain rated voltage, high quality power conversion, power flow control, fault protection, system balancing, and maximum power point tracking of various DGs. The work of Kumar (2020) discusses that, a control strategy of 3-phase back-to-back PWM VSC is presented for doubly fed induction generator for controlling the power generation in the WT DG. The same control strategy is implemented in the WT DG integrated to the proposed DCMG, in this work.