一种考虑累计调节量的虚拟同步机准同期方法

A Quasi Synchronization Method of Virtual Synchronous Generator Considering Cumulative Regulation

虚拟同步机(VSG)在新能源发电侧及配电微网中取得了广泛应用,在具体应用场景中,离网模式转为并网模式需要VSG进行同期调节,待满足同期条件后,方可并入电网。同时,中大规模微网通常由多台VSG并联而成,需保证微网中各台VSG在同期过程中均匀出力,而实际工程中部分VSG同期时会出现掉线恢复后出力不均的现象。为此提出了一种考虑累计调节量的VSG同期方法,VSG参考整个同期过程的累计调节量,计算得出此次调节步长并与当前的同期指令进行综合判断,最终得出调节方向及调节量。该方法可使各VSG满足当前时刻同期调节需求的同时补齐同期过程的出力差距,最终实现各VSG均匀出力,实现准同期并网。

The virtual synchronous generator(VSG) has been widely used in the new energy generation side and distribution micro-grid.In the specific application scenario,when the off grid mode is changed to the grid connected mode,the VSG is required to adjust in the same period,and can be incorporated into the power grid only after the same period conditions are met.At the same time,the medium and large-scale micro grid is usually composed of multiple VSG in parallel.It is necessary to ensure that each VSG in the micro grid has uniform output during the same period,while in the actual project,some VSG will have uneven output after line dropping recovery during the same period.A VSG synchronization method considering the cumulative regulation is proposed.By referring to the cumulative regulation of the whole synchronization process,the adjustment step size is calculated and judged comprehensively with the current synchronization instructions,and finally the adjustment direction is obtained.This method can make each VSG meet the current demand of synchronous regulation,and at the same time make up the output gap of the synchronous process,and finally realize the uniform output of each VSG,and realize the quasi synchronous grid connection.