A multi-terminal flexible DC network longitudinal protection method and system based on current limiting inductor voltage polarity

[0045] In some implementations, a method for longitudinal protection of DC lines in a multi-terminal flexible DC grid based on the voltage polarity of a current-limiting inductor is disclosed, such as Figure 13 shown, including the following steps:

[0046] (1) Let the two ends of the line be the M terminal and the N terminal respectively, and collect the voltage value v of the current-limiting inductor at both ends of the DC line in real time Li(i represents the positive pole p or negative pole n at one end of the DC line);

[0047] (2) Using the voltage gradient algorithm to v Li To process, and then detect whether there is a fault;

[0048] The fault detection criterion and calculation expression are shown in the following formula,

[0049] |▽v L (k)|>Δ 1 (1)

[0050]

[0051] In the formula, v L (k),▽v L (k) are the voltage value and voltage gradient value of the kth sampling point on the current-limiting inductor; Δ 1 is the starting threshold; k and j are samp

[0130] In some embodiments, a multi-terminal flexible direct current grid pilot protection system based on the voltage polarity of the current-limiting inductor is disclosed, including a server, the server includes a memory, a processor, and a memory stored on the memory and can run on the processor A computer program, the processor implements the multi-terminal flexible DC grid longitudinal protection method based on the voltage polarity of the current-limiting inductor described in Embodiment 1 when executing the program.

[0132]In some embodiments, a computer-readable storage medium is disclosed, on which a computer program is stored. When the program is executed by a processor, the multi-terminal flexible DC grid based on the voltage polarity of the current-limiting inductor described in Embodiment 1 is implemented. Pilot protection method.