一种基于虚拟同步机的背靠背系统控制策略

本文将虚拟同步机控制策略应用至背靠背变换器系统中，提出一种直流母线电压平衡的控制策略，在模拟同步电机外部特性的同时，实现功率双向流动。通过仿真表明，与dq旋转坐标系下的传统控制策略相比，虚拟同步机控制功率切换更为平滑，谐波含量更低。本文在对背靠背系统进行建模分析的基础上，根据三种不同的性能指标分析两种控制策略的优劣。在此基础上将背靠背系统作为能量平衡系统，平衡两个电网之间的功率负载分配。在没有锁相环和dq解耦模块的基础上，简化控制设计，实现能量平衡。

A Back-to-back System Control Strategy Based on Virtual Synchronous Generator

This paper applies the virtual synchronous generator to the back-to-back converter system, and proposes a control strategy to ensure the voltage of DC bus balanced, which both simulates the characteristics of the synchronous generator and realizes the power bidirectional flow. Compared with the traditional control strategy in dq rotating coordinate system, power switching of the virtual synchronous generator is smoother and the harmonic content is lower. Based on the modeling of the back-to-back system, this paper analyzes the advantages and disadvantages of the two control strategies according to three different performance indicators. The back-to-back system is used as an energy balance system to balance the power load distribution between two grids. Without the phase-locked loop and the dq decoupling module, the control design is simplified while the energy balance is achieved.