A power grid fault simulation device and its control method

Abstract

The invention provides a grid fault simulation device and a control method thereof. The power grid fault simulation device adopts the four-arm voltage source main circuit topology; based on the symmetrical component method, the positive sequence, negative sequence and zero sequence voltage commands are respectively obtained; the voltage + current double closed-loop control and the command voltage feedforward control are adopted to realize the output voltage. Accurate and fast control of frequency and frequency; by setting the depth of voltage drop and frequency value, the simulation of common grid faults such as three-phase symmetry, two-phase asymmetry, single-phase asymmetry and abnormal frequency can be realized, which can meet the requirements of photovoltaic power plants and wind farms. Fault ride through and grid adaptability test requirements. Each part of the invention has clear functions, is simple and effective, and is beneficial to engineering application.

Description

Technical field[0001]The invention belongs to the field of electrical engineering, and specifically relates to a power grid fault simulation device and a control method thereof.Background technique[0002]As the penetration rate of photovoltaic power generation and wind power generation in the power system continues to increase, their impact on the grid can no longer be ignored. Especially in China, photovoltaic and wind power use large-scale centralized access to the grid. When the grid fails, the grid connection point During a voltage drop, if photovoltaic power plants and wind turbines still adopt passive protection and unloading methods, it will result in a significant reduction in active power output, which will not only increase the difficulty of recovery of the entire system, but may even exacerbate failures, leading to the collapse of grid voltage and frequency, and serious impacts The safe and stable operation of the power grid also greatly limits the large-scale utilization ...

AI Technical Summary

Problems solved by technology

[0003] At present, domestic power grid fault ride-through simulation devices mainly adopt impedance divider type and power electronic type. Because of the use of reactors, the former is not only large in size, unable to realize continuous and smooth adjustment of voltage drop amplitude, but also difficult to simulate high-voltage ride-through and Abnormal frequency; although the latter can make up for the inherent defects of the impedance divider device, it mainly depends on imports and is expensive

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