虚拟同步储能变换器的功率环双模式控制

Power Loop Based Dual Mode Control of Virtual Synchronous Energy Storage Converter

根据虚拟同步储能变换器功率环主要参数的相互影响进行了小信号建模分析,为功率环参数设计和选取范围提供了参考。据此,针对虚拟储能变换器并网运行时存在的稳态功率偏差和功率限额问题,提出一种适用于并网工况的储能变换器虚拟同步机PQ模式控制策略,并在必要时将PQ模式与VSG下垂模式进行切换。虚拟同步发电机(VSG)的PQ模式并网除了能实现稳态时恒功率运行外,暂态过程中还具有一定的惯性和阻尼,并网状态下能够自同步,无需锁相环。仿真和实验结果表明,所提双模式控制策略稳定可靠且切换平滑。

The mutual influence of the key parameters for the power loop of virtual synchronous storage converter is analyzed in small signal model,which provides a reference for the design and selection of the power loop parameters.According to the deficiency of power deviation and limit under grid-connected operation for virtual synchronous storage converter,a PQ mode control strategy of virtual synchronous machine which is suitable for grid-connected operation is presented,and the switching between PQ mode and the virtual synchronous generator(VSG)mode which is operated when it is necessary.The PQ mode control can not only realize constant power operation in steady state,but also have certain inertia and damping in transient process.It can realize self-synchronization in grid-connected state,and the phase-locked loop is not needed.Finally,the simulation and experimental results show that the proposed control strategy is stable,and smooth switch is also reliable.