How to compensate for low power factor when the load is not running, and how to solve the problem of low power factor in long-distance cable lines. In response to the problems of increased power loss, decreased power factor, and inability of isolation switches to close the no-load line caused by capacitive current in long-distance cable lines, through power flow analysis of cable lines, it is concluded that the root cause of the above problems is excessive capacitive reactive power due to excessive capacitive current in no-load and light load lines.
When the capacitance current of the no-load line exceeds 5A, parallel reactors can be used on the circuit breaker side to limit it. When the capacitance current of the no-load line does not exceed 5A, but reactive power is fed back to the grid during light load operation, parallel reactors can be installed on the high-voltage bus to limit or static reactive power generators (SVG) on the low-voltage side of the main transformer can be used to limit.