High-precision control method of island npc power supply with fast dynamic response

Abstract

The invention discloses a high-accuracy island NPC type power supply control method capable of realizing rapid dynamic response. The dynamic response speed of a system is effectively improved through feedforward of medium / high-frequency components of load current, severe disturbance of output voltage of a power supply under impact load is reduced, and the disturbance rejection performance of an NPC type power supply is enhanced; besides, the outer voltage loop adopts QPR control and repeated control, and no static error control of output voltage at the fundamental frequency and the primary subharmonic frequency is realized, so that the control accuracy of output voltage of the island NPC type power supply is improved; the dynamic response performance of the system and the control accuracy of output voltage of the system can be effectively improved, the system stability is enhanced, and the reliable power supply difficulty of defense facilities and civil equipment on the island is solved.

Description

technical field [0001] The invention relates to the field of power supply for special loads in sea islands, in particular to a high-precision control method for NPC power supplies in sea islands with fast dynamic response. Background technique [0002] With the development of society and economy, human beings' demand for electric power is increasing day by day, and the regional scope of electric power application is expanding. big. Among them, the natural environment of the island is particularly harsh, making it difficult for the power system to operate reliably for a long time, and frequent failures occur at high temperatures above 70 degrees. At the same time, metal facilities are severely corroded in the "natural corrosion box" environment. At the same time, the island power supply often works in a weak grid or independent power supply mode, which easily affects the robustness and anti-interference performance of the power supply, and makes the power supply unreliable. ...

AI Technical Summary

Problems solved by technology

Among them, the natural environment of the island is particularly harsh, which makes it difficult for the power system to operate with high reliability for a long time, and frequent failures occur at high temperatures above 70 degrees. At the same time, metal facilities are severely corroded in the "natural corrosion box" environment.

At the same time, the island power supply often works in a weak grid or independent power supply mode, which can easily affect the robustness and anti-interference performance of the power supply, and cause unreliable power supply

On the other hand, the impact load of the island will not only affect the safety and stability of the power grid environment, but also have an impact on related power equipment

For system voltage fluctuations caused by impulsive reactive loads, static dynamic var compensation devices (SVC devices) are generally installed in each workshop, but this method is not economically applicable and is not suitable for islands with changing environments; Large disturbances will aggravate the impact of impact loads on transient stability

In the research example, when large disturbances occur in the power grid in this area, such as unit tripping, line disconnection, etc., the stability of the system can be maintained by quickly removing part of the large-capacity impact load, but for the user, this method caused great inconvenience

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