Virtual synchronous generator (VSG) simulates the first-order motion equation of a synchronous generator (SG) with the algorithm. VSG can improve the system voltage and frequency support capabilities of a microgrid or a weak grid. It is now widely applied at a high penetration level of distributed generation (DG) systems. However, because there is a contradiction between active power steady-state deviation of VSG and dynamic impact regulation, the VSG running in grid-connected mode with existing strategies cannot meet the steady and dynamic control requirements. Thus, an improved virtual inertial control strategy of VSG is proposed in this paper. The active power impact is reduced effectively under the circumstance of damping coefficient D ω equal to 0 and a large inertia, thus the dynamic characteristic of active power is improved and its steady-state characteristic is maintained. Firstly, based on the analysis of the damping coefficient effect on the system dynamic process, two forms of improved virtual inertia algorithms are put forward by cascading a differential link into different positions of the first-order virtual inertia forward channel. Then, by comparing the characteristics of the system with the two improved algorithms, the improved virtual inertial strategy based on differential compensation is proven to be better, and the design of its parameters is analyzed. Finally, simulation and experimental results verify the effectiveness of the proposed algorithm.

中文翻译：

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虚拟同步发电机的一种改进的虚拟惯量算法

虚拟同步发电机（VSG）使用该算法模拟了同步发电机（SG）的一阶运动方程。VSG可以提高微电网或弱电网的系统电压和频率支持能力。现在，它已广泛应用于分布式发电（DG）系统的高渗透级别。然而，由于VSG的有功功率稳态偏差与动态影响调节之间存在矛盾，因此采用现有策略并网运行的VSG无法满足稳态和动态控制的要求。因此，本文提出了一种改进的VSG虚拟惯性控制策略。在阻尼系数D的情况下有效降低了有功功率的影响 ω等于0且惯性较大，因此改善了有功功率的动态特性，并保持了其稳态特性。首先，在分析阻尼系数对系统动力学过程的影响的基础上，通过将差分链路级联到一阶虚拟惯性正向通道的不同位置，提出了两种形式的改进的虚拟惯性算法。然后，通过将系统特性与两种改进算法进行比较，证明了基于差分补偿的改进虚拟惯性策略是更好的，并对其参数设计进行了分析。最后，仿真和实验结果验证了该算法的有效性。