Method and device for determining the occurrence time of transient voltage disturbance in AC system
A technology of occurrence time and transient voltage, applied in the direction of measuring current/voltage, measuring device, power transmission AC network, etc., can solve problems such as difficulty and complex structure of AC power grid
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Embodiment 1
[0058] Transient voltage disturbances of the same amplitude have different phases and have different effects on the operating state of the DC system. Therefore, determining the phase of the transient voltage disturbance of the AC system is one of the important parameters for analyzing the influence of the transient disturbance of the AC system on the operating state of the DC system. When the power grid structure is constant, the operating phase difference of each site in the power grid depends on the power flow of the power grid, and when a fault occurs in a certain position of the power grid, according to the principle of refraction and reflection of waves, the phase of the disturbance at a specific node is directly related to the position of the node and the fault point. relevant. The voltage disturbance phase on a grid node is not consistent with the fault phase of the fault point. Therefore, the fault phase of the fault point cannot be used to represent the voltage distu...
Embodiment 2
[0076] refer to figure 1 As shown, the method provided in this embodiment also includes steps:
[0077] 108. Introduce the phase reference time to convert the disturbance occurrence time into the disturbance occurrence phase, specifically,
[0078]
[0079] In the formula, is the disturbance generation phase, t f is the disturbance occurrence time, t a Disturbance time t f The first zero-crossing time before.
[0080] This embodiment collects the fault recording data of converter station 1# and converter station 2# in a certain place in recent years. The calculation results of AC disturbance phase of phase failure are as follows: Figure 4 shown. According to the calculation results, the disturbance phases of the commutation failure cases of the 1# DC project are mainly concentrated at 90°-126°, accounting for 70.7% in total, while the disturbance phases of the commutation failure cases of the 2# DC project are mainly concentrated at 72°-108° , accounting for a tot...
Embodiment 3
[0082] In the method provided in this embodiment, in step 108, it is distinguished whether the disturbance occurs in the positive half-cycle phase or the negative half-cycle phase, specifically, t f with t a Choose any point between them, and judge the position where the disturbance occurs according to the positive or negative value of the point. Specifically, if the value of this point is positive, the disturbance occurs in the positive half-cycle phase; if the value of this point is negative, the disturbance occurs in the negative half-cycle phase.
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