三相光伏并网逆变器状态空间模型与矢量控制

随着分布式发电的发展,分布式发电系统成为旋转设备发电机和逆变器接口发电机构成的混合电力系统.系统稳定性分析需要研究状态空间模型,以及合适的逆变器模型,从而对已经成熟的旋转电机模型进行必要的补充.电机模型包括自动电压控制器AVR(automatic voltage regulator)和功率补偿功能,逆变器模型包括锁相环功能和内部控制功能等.基于三相光伏并网电压源型逆变器模型,进一步分析内部电流控制环,外部功率控制环,平均功率测量以及PLL技术.所有模型采用状态向量技术进行详细推导,类似于旋转电机的数学模型分析.模型包含非线性项,但能在运行点上线性化,基于MATLAB SIMULINK/PLECS仿真平台,对状态空间模型的并网系统进行数字仿真,仿真结果表明基于状态空间的数学模型和空间矢量控制,能有效改善并网电流的电能质量,实现并网要求.

The State Space Model and Vector Control of Three-phase Photovoltaic Grid-connected Inverter

with the development of distributed generation, distributed power system is becoming the hybrid power system of rotating generator and inverter interfaced generator. The stability of such power network needs to be studied through the analysis of space state model and suitable inverter model, which is very necessary complement for the well established rotating machine. The motor model include automatic voltage regulator and power compensation function, the inverter model include phase lock loop, internal control loop etc. based on the model of three phase grid-connected voltage source inverter, the internal current loop, outer power control loop, average power measurement and phase locked loop were further analyzed. All the models were derived from state space technique, which is very similar to the analysis of rotating machine. The model contains non-linear terms but can be linearized at the operating point. Based on the simulation environment of Matlab Simulink/Plecs, the grid-connected inverter system based on state space model was analyzed, the simulation result show that the mathematical model and state space control can effectively improve the power quality of grid current, thus the requirement of inverter connected to power grid is thus accomplished.