Low-frequency oscillation suppression method and system for multi-port AC/DC hybrid power distribution network

Abstract

The invention relates to the technical field of power system stability, in particular to a low-frequency oscillation suppression method and system for a multi-port AC / DC hybrid power distribution network. The method comprises the steps: configuring an oscillation suppression additional controller on a controller of a three-phase Buck circuit link of the alternating-current and direct-current power distribution network; determining configuration parameters of a phase compensation link; determining a time constant of a signal filtering link, and determining a gain coefficient of the signal; and superimposing the oscillating signal on the Buck controller current inner loop through the additional controller so as to complete the suppression of the oscillating signal in the multi-port AC / DC hybrid distribution network. Compared with the prior art, no additional equipment is needed, operation is convenient, the method can effectively improve the damping of the AC / DC power distribution network, suppresses low-frequency oscillation, improves the stability of the system, and can be widely applied to suppression of low-frequency oscillation in an alternating-current and direct-current power distribution network containing a power electronic transformer.

Description

technical field [0001] The invention relates to the technical field of power system stability, in particular to a low-frequency oscillation suppression method and system for a multi-port AC-DC hybrid distribution network. Background technique [0002] As an important part of the power system, the distribution network plays a key role in distributing electric energy to the majority of power users. The traditional AC power distribution system faces a series of problems such as high line loss, power quality disturbance, and voltage drop, and it is difficult to meet the growing power demand of power users; there is no synchronization problem in the DC part of the AC-DC hybrid distribution network, which can effectively isolate the AC side. Disturbances and faults, ensuring high reliability power supply. Building an AC-DC hybrid distribution network on the basis of the AC distribution network is the development trend of the future distribution network. [0003] However, the cur...

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Problems solved by technology

However, these methods are often aimed at large-scale interconnected power systems and are used to suppress low-frequency oscillations between regions. However, there are fewer suppression methods based on low-frequency oscillations in multi-port AC-DC hybrid distribution networks. It is complex and has a lot of equipment, including power electronic transformers, inverters, DC-DC converters and other equipment, with various control methods. It is difficult to select input and output when designing additional controllers, and it is challenging to determine the form of additional controllers

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