An insight into Micro Grids By Engr. Sheikh Muhammad Ibraheem

Author Biography

Sheikh Muhammad Ibraheem is a student of electrical engineering, an author, and a researcher from Pakistan. He is an active member of NSPE and IEEE world’s largest engineering communities. His books are published across the globe and is currently studying in The University of Lahore.

A microgrid is a small, locally controlled electrical system with clearly defined electrical borders. It can run in both grid-connected and island modes. A “Stand-alone micro grid,” also known as a “isolated microgrid,” can only run off the grid and is not able to be connected to a larger electrical power network. Grid-connected micro grids typically operate synchronously and in connection with the conventional wide area synchronous grid (macrogrid), but they also have the flexibility to operate independently in “island mode” when necessary due to technical or practical considerations. By switching between linked and island modes, they increase the micro grid cell’s supply security and are able to provide emergency power. These grids are referred to as “islandable microgrids.” A standalone micro grid is equipped with an energy storage system in addition to its own power generation sources. When a significant centralised energy source is too far away or too expensive to run, these systems are employed for power transmission and distribution. They give distant communities and smaller geographical islands a choice for rural electricity. An independent micro grid may efficiently include several distributed generation (DG) sources, particularly renewable energy sources (RES). Micro grid Benefits When the utility fails, micro grids are intended to keep a company’s mission-critical loads operational. Many are capable of supporting all loads, or all but unnecessary and pending loads. Microgrids can reduce expenses. On-site power generation for micro grids is frequently incorporated into cogeneration and district energy systems. When compared to central utility stations that are not intended to take advantage of the heat produced as a byproduct of power generation, combined heat and power systems are frequently twice as efficient. Micro grids have the potential to develop as safe havens during local emergencies. Even a single micro grid can make a significant difference in a town if a major storm disrupts electricity service. Several Central Atlantic micro grid operators allowed first responders and locals access to their facilities after Hurricane Sandy so they could gather, dry off, and charge phones and radios. Community Grids Community micro grids can assist the uptake of local energy while providing services to thousands of clients (electricity, heating, and cooling). Some homes in a community micro grid might have renewable resources that can meet both their own and their neighbours’ needs for energy. The community micro grid could also include a single distributed energy storage system or a number of them. Such micro grids could take the shape of a bi-directional power electronic converter-coupled ac and dc micro grid. Micro grid Topologies 1. AC Micro grid: Through an AC/AC converter, power sources with AC output are connected to an AC bus. This converts the AC’s changeable frequency and voltage to an AC waveform with a different frequency and voltage. While DC/AC converters are used to connect power sources with a DC output to an AC bus. 2. Hybrid Micro grid: The hybrid micro grid has a topology for both AC and DC output power sources. Additionally, a bidirectional converter connects AC and DC buses to one another, enabling power to move between the two buses in both directions. 3. DC Micro grid: The DC micro grid topology connects power sources with DC output to the DC bus either directly or through DC/DC converters. However, power sources that provide an AC output are connected to the DC bus using an AC/DC converter.