6.2.2母线保护变电所的母线是电力系统的-个重要组成元件，当母线上发

6.2.2 The busbar of the bus protection <br>substation is an important component of the power system. When a fault occurs on the busbar, it will cause all the components connected to the faulty busbar to be transferred to another group during the repair of the busbar fault The failed bus was forced to power off before running. In addition, the failure of the busbar of the substation of the hub of the power system may also cause the destruction of the system stability and cause serious consequences. <br>The short-circuit faults occurring on the bus may be various types of grounding and phase-to-phase short-circuit faults. The proportion of bus short-circuit fault types is different from that of transmission lines. Among the short-circuit faults of transmission lines, single-phase ground faults account for more than 80% of the total. In bus faults, most of the faults are caused by insulator-to-ground discharges. The initial phase of bus faults mostly manifests as a single-phase ground fault, and as the short-circuit arc moves, the fault often develops into two-phase or three-phase ground. Short circuit. <br>In general, no special busbar protection is used, but the protection of the power supply components can eliminate the busbar fault. For example: the low-voltage side bus of the step-down substation is normally operated separately. If it is connected to the low-voltage side bus as the feeder line, the fault of the low-voltage bus can be caused by the overcurrent protection of the corresponding transformer to make the transformer circuit breaker The trip is removed. <br><br>①.35 kV is a single bus section with side bus connection, no special protection is used. When the bus is faulty, the fault can be removed by the 35kV side circuit breaker of the transformer. <br>②.10 kV is a single bus section wiring without special protection. When the bus fails, the 10kV side circuit breaker of the transformer can be tripped to remove the fault.

6.2.2 Bus protection<br>The busofe of the substation is the power system - an important component that, when the bus failed, will force a power outage before all components connected to the fault bus line are repaired during the fault, or converted to a fault-free bus. In addition, in the power system, the hub substation bus failure, may also cause the stability of the system damage, causing serious consequences.<br>Short-circuit faults that occur on the bus may be of various types of ground and interphase short-circuit faults. The proportion of bus short-circuit fault type is different from that of a transmission line. In the short circuit fault of transmission line, single-phase ground fault accounts for about 80% of the total. In the bus fault, most of the fault is caused by the insulator-to-ground discharge, the start of the bus fault is mostly a single-phase ground fault, and with the movement of the short-circuit arc, the fault often develops into a two-phase or three-phase ground short circuit.<br>In general, without special bus protection, the use of the power supply element protection device can be removed. For example: the low-voltage side bus line of the buck substation operates separately when normal, if connected with the feed line on the low-voltage side bus, the fault on the low-voltage bus can be protected by the overcurrent of the corresponding transformer so that the transformer circuit breaker tripped to be removed.<br><br>(1.35 kV) is a single-female segment with side-mother wiring, without special protection, when the bus failure, the transformer 35 kV side circuit breaker can jump-off cut the cut fault.<br>(2. 10 kV is a single-parent segmented wiring, without special protection, when the bus fault, the transformer 10 kV side circuit breaker can jump off the cut fault.)

6.2.2 bus protection<br>The bus of the substation is an important component of the power system. When there is a fault on the bus, all the components connected to the fault bus will be forced to cut off power before repairing the bus fault or switching to another group of fault free buses. In addition, when the bus bar of the hub substation in the power system breaks down, it may also cause the system stability damage, resulting in serious consequences.<br>The short circuit fault on the bus may be various types of ground and phase to phase short circuit fault. The proportion of bus short circuit fault types is different from that of transmission lines. In the short-circuit fault of transmission lines, single-phase ground fault accounts for more than 80% of the total. In the bus fault, most of the faults are caused by insulator to ground discharge. At the beginning of bus fault, most of them are single-phase ground fault. With the movement of short-circuit arc, the fault often develops into two-phase or three-phase ground fault.<br>Generally speaking, the bus fault can be removed by using the protection device of power supply elements instead of special bus protection. For example, the line of the low-voltage side bus of the step-down substation operates separately when it is normal. If the line connected to the low-voltage side bus is the feeder line, the fault on the low-voltage bus can be removed by the over-current protection of the corresponding transformer to trip the transformer breaker.<br>① . 35kV is a single bus section with side bus connection, without special protection. When the bus fails, the breaker at 35kV side of the transformer can jump open and cut off the fault.<br>② . 10kV is a single bus section connection, without special protection. When the bus fails, the 10kV side breaker of the transformer can jump open to cut off the fault.<br>