1) Single busbar connection. Single busbar connection has the advantages of being simple and clear, requiring less equipment, requiring less investment, being easy to operate and convenient for expansion, but it has poor reliability and flexibility. When the busbar or busbar disconnector fails or is under maintenance, all power supply to the busbar must be disconnected. (2) Double busbar connection. Double busbar connection has the advantages of reliable power supply, convenient maintenance, flexible dispatching and easy expansion. However, this type of connection uses more equipment (especially disconnectors), the power distribution device is complex, and the economy is poor. During operation, the disconnector is used as an operating electrical appliance, which is prone to misoperation and is inconvenient for automation. Especially when the busbar system fails, a large number of power supplies and lines must be cut off in a short time, which is not allowed for particularly important large power plants and substations. (3) Single or double busbar or busbar section with bypass. It has high power supply reliability and is flexible and convenient to operate, but the investment is increased and the economy is slightly worse. Especially when the bypass circuit breaker is used to drive the circuit, the operation is complicated and the chance of misoperation is increased. Meanwhile, the addition of bypass circuit breakers complicates the corresponding protection and automation systems. (4) 3/2 and 4/3 wiring. It has high power supply reliability and operational flexibility. No power outage will occur if any busbar fails or is under maintenance; except for the short-term power outage of the two circuits connected to it when the tie circuit breaker fails, no power supply will be interrupted by any other circuit breaker failure or maintenance; even in the extreme case of two sets of busbars failing at the same time (or one set failing when the other is under maintenance), the power can still be transmitted. However, this wiring uses more equipment, especially circuit breakers and current transformers, which requires a large investment, and the secondary control wiring and relay protection are relatively complex. (5) Busbar-transformer-generator unit wiring. It has the characteristics of simple wiring, fewer switching equipment, easy operation, easy expansion, and reduced short-circuit current on the low-voltage side of the generator and main transformer because no generator outlet voltage busbar is set.