Power grid short-circuit current probability evaluation method containing distributed photovoltaic power generation system

Abstract

The invention discloses a power grid short-circuit current probability evaluation method containing a distributed photovoltaic power generation system. The method comprises the following steps: establishing a power grid fault event information model and a photovoltaic power generation low-voltage off-grid probability model; utilizing a Monte Carlo method to randomly simulate a fault event; acquiring related parameters from the simulation result of the fault event; calculating the off-grid probability of each photovoltaic power generation system; calculating an injection current expected valueof each photovoltaic power generation system; calculating fault point short-circuit current under the current fault event according to the injection current expected value of each photovoltaic power generation system; and counting the short-circuit current of the fault point to obtain the probability distribution of the short-circuit current of the fault point. According to the invention, a probability and statistical method is adopted to convert an uncertainty problem into a plurality of determined simulation fault events for solving, and objectivity of short-circuit current probability evaluation is reflected.

Description

technical field [0001] The invention relates to the technical field of photovoltaic power generation, in particular to a method for assessing the probability of short-circuit current in a power grid including a distributed photovoltaic power generation system. Background technique [0002] Distributed photovoltaic power generation has the advantages of clean and efficient, nearby utilization and local conditions. In recent years, the installed capacity of photovoltaic power generation in the distribution network has continued to expand. When the grid-connected point voltage of photovoltaic power generation drops, it must maintain non-off-grid operation according to the low-voltage ride-through requirements, and the injected short-circuit current is determined by the voltage drop of the grid-connected point and the low-voltage ride-through control; when the grid-connected voltage drops seriously, photovoltaic power generation is allowed to exit At this time, the photovoltaic ...

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Problems solved by technology

[0003] Aiming at the deficiencies of the above-mentioned prior art, the present invention provides a grid short-circuit current probability evaluation method including a distributed photovoltaic power generation system, which solves the technical problem in the prior art that the short-circuit current is difficult to determine due to the randomness of the voltage drop at the grid-connected point of photovoltaic power generation

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