High voltage power distribution, which switches inside and outside to do double power switching, the realization of double power grid access is feasible?
When the phase sequence and phase are the same, the 10KV distribution network can carry out the short circuit close loop load without interruption in principle, but the calculation and test should be carried out under certain conditions. To consider: two power supply from different power points, line protection coverage, two days of the line with the load (size and nature),
When the phase sequence and phase are the same, the 10KV distribution network can carry out the short circuit close loop load without interruption in principle, but the calculation and test should be carried out under certain conditions.
The voltage at both ends and the power flow after the closing of the loop will cause tripping because of the excessive power transfer, and then the influence of the line failure on the power grid when the loop is closed. Our city network has carried on the 10KV short-term dumping experiment, is quite successful, to the limited condition many, usually usually uses the short-time power failure to deliver the load. High voltage power grids above 110KV are generally used for short loop closing.
Considering the two power supply power supply from different point, the scope of protection of transmission line protection, the two day line load conditions (size and nature), both ends of the voltage loop, the power flow transfer, whether due to excessive flow transfer trip, then in closing the ring line influence failure on the grid.
Dual power supply switching principle must be a power supply after removal of another power to input, can not let the two power in parallel operation, this will make the system short circuit capacity increased, once the short circuit fault, power circuit breaker may have some water breaking capacity is not enough, causing the accident to expand.
