<p style="text-align:justify"><span style="font-size:14px">As already discussed, voltage of transmission is a function of the amount of power to be transmitted and the distance to which this power is required to be transmitted. This voltage is &nbsp;optimum and is an economical choice. Hence, there will be different voltages of transmission and distribution used from source to final consumer. Hence at source, voltage is stepped up and further towards distribution end, stepped down. This requires power transformers to be installed at many locations from source to load. This requires substations. Also, a power system is an interconnected network in which there are many nodes. These nodes are known as substations. </span></p>

<p style="text-align:justify"><span style="font-size:14px">In this substation, many (two or more than two) transmission lines are incoming and many lines are outgoing. Voltage is stepped up or stepped down. Measurement of current, voltage, power and other electrical quantities is required. The equipment protections require protective gear. Hence there are many equipments in the substation. Substation design and project engineering is a subject by itself and shall be offered as a separate module, but we will have a bird&#39;s eye view of a substation. </span></p>

<p style="text-align:justify"><span style="font-size:14px">The equipment in a substation and their functions in brief are enlisted below. The relative locations of these equipment can be well appreciated in the single line diagram of figure 5.1.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </span><span style="font-size:16px">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;<img alt="" src="https://edupmquestionhelp.s3.ap-south-1.amazonaws.com/hint/uploads/images/16163216051616321605.jpg" style="float:left; height:1102px; width:600px" /></span></p>