Measures to limit short-circuit current in power systems include

Measures:

1. Use FCL to limit short-circuit current, which has the following advantages: 1. Under normal circumstances, the size of the fault current will change with the change of the voltage level. , when the voltage is very high and a fault occurs, it is difficult to disconnect the current, and FCL can directly reduce the pressure on the circuit breaker and help it operate normally. Under normal circumstances, FCL remains closed. When a short circuit occurs, FCL will automatically sense and quickly transmit power to the circuit breaker to ensure that it normally cuts off current.

2. Rapidly limiting the short-circuit current can reduce the voltage loss of the line and the out-of-step probability of the generator. If an appropriate current limiter can be configured, the system's power angle stability, voltage stability and frequency stability can be achieved. With effective improvements, power grid and equipment accidents can be effectively controlled

3. At present, the actual transmission capacity of transmission lines is below the stability limit. If the current limiter can function before the short-circuit current reaches its peak value, As a result, the thermal stability limit and dynamic stability limit required in the design and selection of most equipment can be reduced, and the thermal limit and stability limit ratio of the power grid can also be reduced accordingly, thereby greatly improving the utilization rate of the transmission line and reducing the overall The FCL achieved by investment in current-limiting fuses in the power grid,

Second, taking measures from the system structure combined with system planning, taking measures from the system structure can be considered: developing a higher voltage power grid; using white current Networking; new large-capacity power plants should try to connect to the highest voltage network; when building new transmission lines, pay attention to reducing the density of the network; partition power supply, low-voltage power grid operation in slices, multi-busbar operation in series or busbar segmentation operation The various ideas and methods mentioned above should be researched and formulated based on the actual network conditions and technical and economic perspectives to ensure the reliability of power supply to the greatest extent.

3. Use a current-limiting transformer and connect a reactor in series to numerically increase the resistance value of the system. This is very effective in limiting short-circuit current.