Backup auto-switching logic testing method for checking changeover manner of power transmission line

The invention relates to the technical field of substation equipment inspection, and discloses a backup auto-switching logic testing method for checking the changeover manner of a power transmission line. The method comprises the following steps: connecting the testing line of a testing instrument; setting the closed state of simulated circuit breaker modules (1DL, 2DL, 4DL, and 5DL) as the initial test state; pushing a test switch (AN3) to a disconnection position in the test state to enable simulated transformation modules (3PT and 4PT) to work, with no alternated current in the circuit; and acting to disconnect the simulated circuit breaker modules (1DL and 3DL) and enabling the simulated transformation modules (3PT and 4PT) to work with alternated current in the circuit by a backup auto-switching device. The tested backup auto-switching device can be added in operation. The method can simulate the changeover and backup auto-switching function of a backup auto-switching power transmission line, and is convenient and reliable in testing the protection setting value of a backup auto-switching protection device. In addition, the method can meet the requirement for inspection of a bridge connection backup auto-switching device in the power system, thereby greatly improving the test flexibility and improving the production efficiency.