<p style="text-align:justify"><span style="font-size:14px">Busbar is a node to which feeders or transmission lines are connected. Busbar is an ACSR conductor of suitable cross-section to meet the total load of all feeders connected to it.</span></p>

<p>&nbsp;</p>

<ul>
	<li style="text-align:justify">
	<p style="text-align:left"><span style="font-size:14px"><strong>Busbar Arrangements: </strong></span></p>
	</li>
</ul>

<p style="text-align:justify">&nbsp;</p>

<p style="text-align:justify"><span style="font-size:14px">Different busbar arrangements used in practice are as follows:</span></p>

<p style="text-align:justify">&nbsp;</p>

<ol>
	<li style="text-align:justify">
	<p><span style="font-size:14px"><strong><u>Single Busbar Arrangement:</u> </strong>Refer figure 5.3.</span></p>
	</li>
</ol>

<p style="margin-left:48px; text-align:justify"><span style="font-size:14px"><img alt="" src="https://edupmquestionhelp.s3.ap-south-1.amazonaws.com/hint/uploads/images/16164847331616484733.jpg" style="height:694px; width:800px" /></span></p>

<p style="margin-left:48px; text-align:justify"><span style="font-size:14px"><strong><u>Advantages: </u></strong></span></p>

<ul>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Most economical arrangement.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">The arrangement occupies less floor space.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Simple arrangement</span></p>
	</li>
</ul>

<h1 style="margin-left:48px; text-align:justify">&nbsp;</h1>

<p style="margin-left:48px; text-align:justify"><span style="font-size:14px"><strong><u>Disadvantages: </u></strong></span></p>

<ul>
	<li style="text-align:justify">
	<p><span style="font-size:14px">There is no flexibility offered. If there is a bus fault, there will be complete dark out for the substation. No power can be fed to any consumer from that substation where there is a bus fault.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">In case of bus fault, fault current will be fed to the fault by all transmission lines connected to that bus. This situation may lead to wide-spread instability of the power system if bus fault is not cleared fast. In the worst case, there can be cascaded tripping resulting in complete dark out of the grid.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Long down time (interruption time) in case of bus fault and related repairs.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">In case of maintenance of a circuit breaker, the concerned transmission line is required to be interrupted.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">In case of busbar maintenance, complete shut-down of substation is required.</span></p>
	</li>
</ul>

<p>&nbsp;</p>

<ol start="2">
	<li style="text-align:justify">
	<p><span style="font-size:14px"><strong><u>Single Bus Arrangement with Sectionalizing Isolator:</u></strong></span></p>
	</li>
</ol>

<p style="margin-left:48px; text-align:justify"><span style="font-size:14px">Such an arrangement is used for 11 kV busbars. Sectionalizing isolator is normally closed. Refer figure 5.4.</span></p>

<p style="margin-left:48px; text-align:justify"><span style="font-size:14px"><img alt="" src="https://edupmquestionhelp.s3.ap-south-1.amazonaws.com/hint/uploads/images/16163221321616322132.jpg" style="height:695px; width:800px" /></span></p>

<p style="margin-left:44px; text-align:justify"><span style="font-size:14px"><strong>&nbsp;<u>&nbsp;Advantages: </u></strong></span></p>

<ul>
	<li style="text-align:justify">
	<p><span style="font-size:14px">The arrangement occupies less floor space.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Yet a simple scheme.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Some flexibility added w. r. t. the preceding arrangement. If there is a bus fault on the left side of the sectionalizing isolator, initially all the breakers of the bus will trip; but immediately afterwards, the sectionalizing isolator is opened and power feed from right side of the bus can be resumed by manually closing the breakers on that side.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">In case of busbar maintenance, all the breakers are required to be opened; but following this operation, sectionalizing isolator can be opened. Then, power feed can be resumed for half of the bus. Bus maintenance can be carried out on remnant half. If it is properly planned, the bus maintenance of the whole bus can be done.</span></p>
	</li>
</ul>

<p style="margin-left:44px; text-align:justify"><span style="font-size:14px">&nbsp;</span></p>

<p style="margin-left:44px; text-align:justify"><span style="font-size:14px"><strong>&nbsp;<u>Disadvantages:</u></strong> </span></p>

<ul>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Cost of three sectionalizing isolators (for three phases) is added w. r. t. preceding arrangement. But isolators are not very costly.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">There is no guarantee of power system stability as in preceding case as sectionalizing isolators cannot interrupt fault current. Hence all breakers will trip threatening system stability.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Long down time in case of bus fault (obviously for half the bus).</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">In case of maintenance of a circuit breaker, the concerned transmission line is required to be interrupted.</span></p>
	</li>
</ul>

<p>&nbsp;</p>

<ol start="3">
	<li style="text-align:justify">
	<p><span style="font-size:14px"><strong><u>Single Busbar Arrangement with Sectionalizing Breaker:</u></strong></span></p>
	</li>
</ol>

<p style="margin-left:48px; text-align:justify"><span style="font-size:14px">This is used for 66 kV buses and sometimes (in the old installations) for 132 kV buses too. The sectionalizing breaker is normally closed. The arrangement is shown in single line diagram of figure 5.5.<u> </u></span></p>

<p style="margin-left:48px; text-align:justify"><span style="font-size:14px"><img alt="" src="https://edupmquestionhelp.s3.ap-south-1.amazonaws.com/hint/uploads/images/16163230751616323075.jpg" style="height:685px; width:800px" /></span></p>

<p style="text-align:justify"><span style="font-size:14px">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<strong> <u>Features of the scheme:</u></strong> </span></p>

<ul>
	<li style="text-align:justify">
	<p><span style="font-size:14px">More flexibility than arrangement number 2. In case of bus fault (say, left half), breakers 1, 3, 4 and sectionalizing breaker will trip. Breakers 2, 5 and 6 will not trip. Hence, there will be no interruption of power feed from other half of the bus even for a moment. Hence power system stability is also partially guaranteed.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Busbar maintenance can be done in a scheduled mode as in case of earlier arrangement. For maintenance, sectionalizing breaker and other breakers in the portion to be maintained can be made off. The remnant half will remain live without any interruption of power.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Cost of six isolating switches and one h. v. circuit breaker results in more costly arrangement than preceding scheme.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">One bay (that for sectionalizing breaker as shown in figure 5.5) is added, hence the arrangement occupies little more space than single bus scheme.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">The arrangement is not so simple as it looks because the bus protection scheme is little complicated.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Long down time in case of bus fault (for partial bus).</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">In case of maintenance of a circuit breaker, the concerned transmission line is required to be interrupted.</span></p>
	</li>
</ul>

<p style="margin-left:48px; text-align:justify"><span style="font-size:14px">However, it seems that there are more demerits than merits, the arrangement is superior to the earlier ones as the improved flexibility and partial guarantee of power system stability are much more important. The chief demerit is only little more cost of equipment, land and protection.</span></p>

<p style="margin-left:48px; text-align:justify">&nbsp;</p>

<ol start="4">
	<li style="text-align:justify">
	<p><span style="font-size:14px"><strong><u>Double Bus Arrangement: </u></strong></span></p>
	</li>
</ol>

<p style="margin-left:48px; text-align:justify"><span style="font-size:14px">In this scheme, two sets of busbars are used (main bus I and main bus II). Both are usually identical. Also, it is a general practice that approximately half the power is transferred through bus I and the other half through bus II. New installations of 132 kV bus and exclusively all 220 kV bus installations use double bus arrangement. The single line diagram of this kind of bus arrangement is shown in figure 5.6.</span></p>

<p style="margin-left:48px; text-align:justify"><span style="font-size:14px"><img alt="" src="https://edupmquestionhelp.s3.ap-south-1.amazonaws.com/hint/uploads/images/16163222131616322213.jpg" style="height:938px; width:800px" /></span></p>

<p style="margin-left:48px; text-align:justify"><span style="font-size:14px"><strong><u>The Status of Breakers and Isolating Switches under Normal Operating Conditions:</u></strong></span></p>

<ul>
	<li style="text-align:justify">
	<p><span style="font-size:14px">B<sub>1</sub>, B<sub>2, </sub>B<sub>3, </sub>B<sub>4</sub> are closed.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">I<sub>1</sub> to I<sub>8</sub> are closed.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">BPI<sub>1</sub> to BPI<sub>4</sub> are open.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">BC is closed.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">BCI<sub>1</sub>, BCI<sub>2</sub> are closed.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">BSI<sub>1</sub>, BSI<sub>3</sub> are closed.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">BSI<sub>6</sub>, BSI<sub>8</sub> are closed.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">BSI<sub>2</sub>, BSI<sub>4</sub> are open.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">BSI<sub>5</sub>, BSI<sub>7</sub> are open.</span></p>
	</li>
</ul>

<p style="text-align:justify"><span style="font-size:14px">The direction of power(current) flow shown in figure 5.6 is typical. Such substations are a part of interconnected network. Hence direction of power flow depends upon generating conditions (how many generators are operating) and load conditions. On both sides (incomer as shown in figure 5.6 and outgoing feeders as shown) there are generators (may be far from the substation or just at the station) and load.</span></p>

<p style="text-align:justify"><span style="font-size:14px">Now, we will discuss the sequence of operation of the breakers and isolators in case of different conditions depicted below:</span></p>

<p style="margin-left:48px; text-align:justify">&nbsp;</p>

<ol start="1" style="list-style-type:upper-alpha">
	<li style="text-align:justify">
	<p><span style="font-size:14px"><strong><u>Maintenance of main breaker I:</u></strong></span></p>
	</li>
</ol>

<ul>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Close BSI<sub>2</sub>.</span></p>
	</li>
	<li>
	<p><span style="font-size:14px">Close BSI<sub>4</sub>.</span></p>
	</li>
	<li>
	<p><span style="font-size:14px">Open BSI<sub>1</sub> and BSI<sub>3</sub>.</span></p>
	</li>
</ul>

<p><span style="font-size:14px">These isolator operations could be carried out on-load because when closing (before closing) BSI<sub>2</sub> (and hence BSI<sub>4</sub> too), the potential difference across its poles was zero. If this potential difference is high (system voltage), only off-load operation is possible. This is because there is no arc-quenching facility in the isolators. Similarly, after closing BSI<sub>2</sub>, while opening (after opening) BSI<sub>1</sub> (and for that matter BSI<sub>3</sub> also), the potential difference across poles of BSI<sub>1</sub> is zero.</span></p>

<p>&nbsp;</p>

<ul>
	<li>
	<p><span style="font-size:14px">Make BC off.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Open isolators BCI<sub>1</sub> and BCI<sub>2</sub></span></p>
	</li>
</ul>

<p style="text-align:justify">&nbsp;</p>

<p style="text-align:justify"><span style="font-size:14px">Now bus I is evacuated and can be maintained. There will be no interruption or discontinuity of power fed to consumers. The procedure depicted at A above is a sequence and cannot be altered.</span></p>

<p style="text-align:justify">&nbsp;</p>

<ol start="2" style="list-style-type:upper-alpha">
	<li style="text-align:justify">
	<p><span style="font-size:14px"><strong><u>There is a bus fault on main bus I:</u> </strong></span></p>
	</li>
</ol>

<p style="text-align:justify"><span style="font-size:14px">All breakers B<sub>1</sub>, B<sub>2</sub>, B<sub>3</sub> and B<sub>4</sub> will trip due to operation of buszone protection. The power interruption will occur till the switching operation is done. However, it is not required to wait till the fault rectification is done on bus I if it is a sustained fault. Power flow can be shifted to bus II. But switching operations will take few (5 to 10) minutes and hence power system stability cannot be guaranteed.</span></p>

<p style="text-align:justify">&nbsp;</p>

<p style="text-align:justify"><span style="font-size:14px">Following switching operations (considering normal operation as original) are to be carried out.</span></p>

<ul style="list-style-type:disc">
	<li style="text-align:justify">
	<p><span style="font-size:14px">Close BSI<sub>2</sub> and BSI<sub>4</sub>.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Open BSI<sub>1</sub> and BSI<sub>3</sub>.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Make BC off.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Open BCI<sub>1</sub> and BCI<sub>2</sub>.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Now make B<sub>1</sub> to B<sub>4</sub> ON.</span></p>
	</li>
</ul>

<p style="text-align:justify">&nbsp;</p>

<p style="text-align:justify"><span style="font-size:14px">Now power is transferred to main bus II. Once the fault is rectified, original situation can be restored. If, during the time of rectification and repairs on bus I, bus II cannot handle total power, some load shedding is required.</span></p>

<p style="text-align:justify">&nbsp;</p>

<ol start="3" style="list-style-type:upper-alpha">
	<li style="text-align:justify">
	<p><span style="font-size:14px"><strong><u>Maintenance of Breaker (say, B<sub>1</sub>):</u></strong></span></p>
	</li>
</ol>

<p style="text-align:justify">&nbsp;</p>

<p style="text-align:justify"><span style="font-size:14px">Following is the sequence of operation:</span></p>

<ul>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Close BSI<sub>2</sub>.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Open BSI<sub>1</sub>.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Close BPI<sub>1</sub>.</span></p>
	</li>
</ul>

<p style="text-align:justify">&nbsp;</p>

<p style="text-align:justify"><span style="font-size:14px">This could be done as potential difference across poles of BPI<sub>1</sub> was zero.</span></p>

<ul>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Close BSI<sub>5</sub>, Open BSI<sub>6</sub>.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Close BSI<sub>7</sub>, Open BSI<sub>8</sub>.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Make B<sub>1</sub> off.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Open I<sub>1</sub>, I<sub>2</sub>.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Change the selector switch to position &ldquo;b&ldquo; in d. c. control circuit (figure 5.7).</span></p>
	</li>
</ul>

<p style="text-align:justify"><span style="font-size:14px">Now breaker B<sub>1</sub> can be maintained without interrupting power in incomer 1. Now if there is a fault in incomer 1, the fault current paths are as follows:</span></p>

<p style="text-align:justify">&nbsp;</p>

<ul>
	<li style="list-style-type:none">
	<ul>
		<li style="list-style-type:none">
		<ul>
			<li style="list-style-type:none">
			<ul>
				<li style="list-style-type:none">
				<ul>
					<li style="list-style-type:none">
					<ul>
						<li style="list-style-type:none">
						<p>&nbsp;</p>
						</li>
					</ul>
					</li>
				</ul>
				</li>
			</ul>
			</li>
		</ul>
		</li>
	</ul>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">From line 3:</span></p>
	</li>
</ul>

<p style="text-align:justify"><span style="font-size:14px">B<sub>3</sub>- BSI<sub>3</sub>- BC- BSI<sub>2</sub>- BPI<sub>1</sub>- Fault in incomer 1.</span></p>

<ul>
	<li style="list-style-type:none">
	<ul>
		<li style="list-style-type:none">
		<ul>
			<li style="list-style-type:none">
			<ul>
				<li style="list-style-type:none">
				<ul>
					<li style="list-style-type:none">
					<ul>
						<li style="list-style-type:none">
						<p>&nbsp;</p>
						</li>
					</ul>
					</li>
				</ul>
				</li>
			</ul>
			</li>
		</ul>
		</li>
	</ul>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">From line 4:</span></p>
	</li>
</ul>

<p style="text-align:justify"><span style="font-size:14px">B<sub>4</sub>- BSI<sub>7</sub>- BC- BSI<sub>2</sub> -BPI<sub>1</sub>- Fault in incomer 1.</span></p>

<p style="text-align:justify">&nbsp;</p>

<ul>
	<li style="text-align:justify">
	<p><span style="font-size:14px">From incomer 2:</span></p>
	</li>
</ul>

<p style="text-align:justify"><span style="font-size:14px">B<sub>2</sub>- BSI<sub>5</sub>- BC- BSI<sub>2</sub>- BPI<sub>1</sub>- Fault in incomer 1</span></p>

<p style="text-align:justify">&nbsp;</p>

<p style="text-align:justify"><span style="font-size:14px">Thus, fault current is passing through bus coupler. Also, referring to figure 5.7, closing of relay contact of protective relay for incomer 1, auxiliary tripping relay will operate which will trip bus coupler and not breaker 1 (breaker 1 is already under maintenance) as selector switch (which is located in control room) is at position &ldquo;b&rdquo; (which normally was at position &ldquo;a&rdquo;). Thus, function of breaker is done by bus coupler and protection (isolation of faulty part from healthy system) is taken care of. However, bus coupler can replace only one breaker and therefore breaker maintenance of only one breaker at a time can be done.</span></p>

<p style="text-align:justify"><span style="font-size:14px"><img alt="" src="https://edupmquestionhelp.s3.ap-south-1.amazonaws.com/hint/uploads/images/16194394241619439424.jpg" style="height:1060px; width:800px" /></span></p>

<p style="text-align:justify">&nbsp;</p>

<p style="text-align:justify"><span style="font-size:14px">At many installations, failures of by-pass isolators were reported. Hence practice of providing such isolators is discontinued at many installations. In this case, maintenance of breaker cannot be done without power interruption in concerned line.</span></p>

<p style="text-align:justify">&nbsp;</p>

<p style="text-align:justify"><span style="font-size:14px">Now, let us summarize quickly, the features of this arrangement:</span></p>

<ul>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Very costly arrangement.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Large floor space required.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Sequence of operation of isolators and breakers and bus protection scheme are very complex.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Hundred percent flexibility. No discontinuity of power to consumers during bus maintenance. Power interruption only for few minutes in case of bus fault.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Power system stability is not guaranteed in case of bus fault.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Very short down time in case of bus fault.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Breaker can be maintained without interrupting power flowing in the transmission line.</span></p>
	</li>
</ul>

<p style="text-align:justify">&nbsp;</p>

<ol start="5">
	<li style="text-align:justify">
	<p><span style="font-size:14px"><strong><u>One and A Half Breaker Arrangement:</u></strong></span></p>
	</li>
</ol>

<p style="margin-left:48px; text-align:justify"><span style="font-size:14px">Figure 5.8 shows a single line diagram of the bus arrangement. There are two buses as in double bus scheme. There is no bus coupler. There are three breakers (say B<sub>1</sub>, B<sub>2</sub> and B<sub>3</sub>) for two lines (say line 1 and line 2). Thus, there are one and a half breaker for a line. That is the reason why the scheme is named as one and a half breaker scheme.</span></p>

<p style="margin-left:48px; text-align:justify"><span style="font-size:14px">Such an arrangement of bus is very costly and is used for all 400 kV busbar installations and bus installations beyond 400 kV (765 kV and 1200 kV).</span></p>

<p style="margin-left:48px; text-align:justify"><span style="font-size:14px">All breakers and isolators in figure 5.8 are ON under normal service conditions.</span></p>

<p style="margin-left:48px; text-align:justify"><span style="font-size:14px"><img alt="" src="https://edupmquestionhelp.s3.ap-south-1.amazonaws.com/hint/uploads/images/16163223351616322335.jpg" style="height:1135px; width:800px" /></span></p>

<p style="margin-left:48px; text-align:justify"><span style="font-size:14px"><strong><u>Features of the scheme: </u></strong></span></p>

<ul>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Very costly scheme.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">The horizontal clearance (due to many isolators) in 400 kV (and beyond) will be very large. This would require large floor space. Hence in such a system, pantograph type isolators (figure 5.9) are used where there are vertical clearances and hence smaller floor space.<img alt="" src="https://edupmquestionhelp.s3.ap-south-1.amazonaws.com/hint/uploads/images/16163231911616323191.jpg" style="height:478px; width:800px" /></span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">The arrangement is very complex and bus protection scheme is also very complex.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Highly flexible scheme. There are multiple routes of power flow. In case of bus maintenance of (say) bus I, just switch off breakers B<sub>1</sub>, B<sub>4</sub>, and B<sub>7</sub> and open isolators I<sub>1</sub>, I<sub>2</sub>, I<sub>7</sub>, I<sub>8</sub>, I<sub>13</sub>, I<sub>14</sub>. There is no discontinuity of power flow. There is neither any discontinuity of power due to fault on bus (say) I, as breakers B<sub>1</sub>, B<sub>4</sub> and B<sub>7</sub> will be tripped by buszone protection scheme.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Power system stability is fully guaranteed as the bus fault does not result in any power interruption. If a single bus cannot handle total power delivered, some load shedding may be required.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">There is no problem of down time due to fault rectification and repairs.</span></p>
	</li>
	<li style="text-align:justify">
	<p><span style="font-size:14px">Breakers can be maintained without interrupting power flowing in the transmission line. More than one breaker can be maintained simultaneously. </span></p>
	</li>
</ul>