电网频率偏差下虚拟同步发电机改进控制研究

虚拟同步发电机(VSG)由于模拟了同步发电机(SG)的调频调压特性和惯性阻尼作用而得到广泛关注。传统的VSG特性分析一般针对电网频率为额定频率的情况,当电网频率不等于额定频率时,仍然采用传统VSG控制将会使VSG动态特性发生变化以及输出有功功率稳态值出现偏差,现有文献对电网频率偏差下的VSG动态特性缺乏分析且现有方案不能完全解决有功功率偏差问题。文章首先分析了电网频率偏差对VSG有功功率和频率特性造成的影响,进而提出一种改进有功频率控制策略,并对改进控制策略进行分析。最后通过matlab/simulink仿真验证所提控制策略在改善动态特性和消除稳态偏差方面的有效性。

Improved control strategy of virtual synchronous generator under grid frequency deviation

The virtual synchronous generator (VSG) has been widely concerned because of imitating the voltage and frequency regulation characteristics and inertial damping of synchronous generator(SG).The traditional VSG characteristic analysis generally aims at the condition that the grid frequency is rated frequency,when the grid frequency is not equal to the rated frequency,the traditional VSG control will change the dynamic characteristics of VSG and lead to the deviation of the output active power steady-state value.The existing literatures pay no attention to the analysis of the dynamic characteristics of VSG under the grid frequency deviation and the existing scheme can not completely solve the power deviation problem.Firstly,the influence of grid frequency deviation on the active power and frequency characteristic of VSG was analyzed in this paper,then,an improved active power control strategy was proposed and analyzed.Finally,the effectiveness of the proposed control strategy was verified by matlab/simulink simulation.