Power grid voltage regulation method of angle form cascade synchronous compensator

Abstract

The invention discloses a power grid voltage regulation method of an angle form cascade synchronous compensator. Unbalanced three-phase power grid voltage is independently subjected to positive and negative sequence voltage detection to obtain positive sequence voltage dq shaft components Vd[P] and Vq[P] and negative sequence voltage dq shaft components Vd[N] and Vq[N]; a difference value between the positive sequence voltage dq shaft components and a voltage control instruction as well as a difference between the negative sequence voltage dq shaft components and the voltage control instruction can be independently obtained, and a deviation is subjected to slip form PI control to obtain a STATCOM (Satellite Communications) line current positive and negative sequence dq shaft control instruction; after the STATCOM line current positive and negative sequence dq shaft control instruction is subjected to synchronous frame transform, zero sequence circulating current is combined to obtain a STATCOM phase current instruction; the STATCOM phase current instruction is subjected to current dead-beat control to obtain each-phase chain link modulating wave signal; carrier phase-shifting modulation is used for controlling each module switch to act, finally, positive sequence reactive current and negative sequence current are injected into a power grid, the positive sequence voltage of the power grid is supported, and the voltage fluctuation of a point of common coupling is reduced; and the negative sequence voltage of the point of common coupling is inhibited, and the unbalance of power grid voltage is improved. A slip form PI control method adopted by the invention can quickly support the positive sequence voltage of the power grid, control the positive sequence voltage of the power grid, inhibit short-time voltage leap and maintain the stability of the power grid voltage.

Description

technical field

[0001] The invention relates to a voltage support strategy of a static synchronous compensator, in particular to a grid voltage regulation method of an angular cascaded synchronous compensator (STATCOM). Background technique

[0002] With the continuous development of the electric power industry, the requirements of the power grid for reactive power supply are becoming increasingly strict, and the traditional reactive power compensation device has been difficult to meet the application requirements of some special occasions. Renewable energy sources such as photovoltaics and wind power are often affected by the natural environment, and have the characteristics of intermittent, randomness and uncertainty. Their output power will fluctuate, resulting in unqualified grid-connected power factors, large voltage deviations, and voltage fluctuations and flicker, which affect the power generation efficiency of new energy sources, and may cause large-scale disconnecti...

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