## 2 Smart Grids System
### Power Supply
#### 2.2.2 Renewable Energy (RE)  
Integrating RE with other power sources is considered to achieve many objectives: (1) reduce the carbon footprint; (2) reduce costs of power consumption [91]. This selection must assure user safety, efficiency, and cost savings for a given application. As a result, criteria such as power consumption, application deployment area, cable size, and line transmission losses are considered. This method was used to create a 48 V DC bus in a small-scale laboratory system with minimal power usage [91]. Furthermore, an electric bus management system (EBMS) considers variables that may have an impact on distribution network or bus efficiency, such as the power tariff. To counteract the negative effects of opportunity charging systems, RE-based charging stations can be installed. The number of possibilities for configuring connections to be lowered during the hours of 22:00-23:00 h, encourages discussion about linked DC motor load with wind and solar power-based hybrid power systems based on a simulated outcome [92]. A battery-based energy storage system is used to control the excess power generation to maximize the utilization of these energy sources based on the required load [93]. The switching transients of renewable sources and batteries do not affect DC motor speed (load), and hence constant output power as per requirement is available. The adaptability of artificial neural networks (ANNs) allows the system to be tested in a different scenario. The controller can be trained for any change in the signal. The training accuracy is 94% [94]. It will also require city utility authorities combining novel grid elements on the Internet of RE domain in order to actualize a sustainable, transformed smart city. In the future, power business, pure renewable electricity grid structural assets, and Internet of RE technology will become increasingly valued [95]. The primary motivation for this expected paradigm shift toward renewable power grids on the Internet is to manage electricity storage [96]. The cross-cutting nature of solely renewable electricity grid architecture on the Internet of RE platforms and intelligent city elements will help shape future environmentally friendly towns [94]. Energy management systems (EMS) for various REs target small DC grids for remote rural communities with unstable load conditions [97].The technology can be used to electrify rural settlements with the greatest possible use of REs and storage devices. The power dissipates to the consumer through maximum RE penetration and batteries throughout the day without any divergence in the system, according to simulation and experimental investigations of the DC micro-grid with the suggested EMS [97]. Micro-grid implementation is a viable method for improving supply quality while lowering sustainable energy implementation costs. For a hybrid micro-grid (HMG), a control scheme presents a structure for ensuring continuous PS to consumers in fifteen different modes of operation. PV, fuel cells, wind, and battery storage with configurable characteristics that were all investigated. The supervisory controller sets the reference values for the generation subsystems using the state machine approach by following a predetermined path. The discrepancy between the generated and demanded power, as well as SoC, are considered by the fuzzy controller during charging and discharging battery banks. As a result, in order to obtain the best system configuration and component sizing by defining objective functions for energy cost and power loss probability, the multi-objective particle swarm optimization (MOPSO) methodology was utilized. The modeling findings show an increase in the price of electricity, which leads to a significant increase in the use of HMG based on renewable resources. As a result, harnessing renewable resources to create electric power in India's remote places is a viable option [98]. Based on the literature, algorithms of battery management, RE, and cloud computing are summarized in Tables 1 and 2.