A low-voltage ride-through control method and system for a photovoltaic-containing DC power distribution system

Abstract

The invention discloses a low-voltage ride-through control method and system of a photovoltaic-containing DC power distribution system, and relates to the field of relay protection of electric power systems. The method includes: Step 1, obtaining the voltage waveform and current waveform of a preset time window at the photovoltaic outlet, and performing Fourier transform processing on the voltage waveform and the current waveform; Step 2, performing Fourier transform processing on the The final data is calculated to obtain the characteristic energy value; step 3, judge whether the power distribution system is faulty according to the characteristic energy value; step 4, if there is the fault, change the control mode of the grid-connected AC station from constant DC voltage to The control is switched to the island mode, and the control mode of the photovoltaic converter station is switched from constant power control to maximum power tracking mode, so that the low voltage ride-through of the power distribution system is achieved. The invention is suitable for relay protection, can solve the problem of insufficient low-voltage ride-through ability, and achieve the effect of improving the system's non-off-grid operation ability.

Description

technical field [0001] The invention relates to the field of relay protection of power systems, in particular to a method and system for controlling low-voltage ride-through of a photovoltaic DC power distribution system. Background technique [0002] With the development of the DC distribution network, photovoltaic systems are widely used due to their distribution range. At the same time, there are some disadvantages. When the power grid fails, if the power generation system is suddenly disconnected from the power grid, the traditional power generation Machines are heavily burdened, which leads to severe power system problems and eventually blackouts. Contents of the invention [0003] The technical problem to be solved by the present invention is to provide a low-voltage ride-through control method and system for a photovoltaic-containing DC power distribution system in view of the deficiencies in the prior art. [0004] The technical solution of the present invention t...

AI Technical Summary

Problems solved by technology

[0002] With the development of the DC distribution network, photovoltaic systems are widely used due to their distribution range. At the same time, there are some disadvantages. When the power grid fails, if the power generation system is suddenly disconnected from the power grid, the traditional power generation caused a heavy load on the machine, which led to severe power system problems and eventually blackouts

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