三相Z源逆变器的模型预测控制

Model Predictive Control of Three-phase Z-source Inverter

模型预测控制因其本身具有快速跟踪响应能力而广泛应用于电力电子领域。本文提出一种基于模型预测控制的三相Z源永磁直驱风力发电系统并网控制方法。针对三相Z源逆变器的特点,在每个采样周期内,使用预测模型对Z源逆变器的9种开关状态进行滚动计算,根据最小化代价函数的原则,选择合适的开关状态,无须经过调制器直接将驱动脉冲输送到逆变桥,成功控制Z源网络电容电压和并网有功功率,实现系统单位功率因数并网。最后在Matlab/Simulink中搭建仿真模型,结果表明,采用模型预测控制的三相Z源逆变器可直接调控并网有功功率,且具有良好的动态性能。仿真验证了理论分析的正确性和有效性。

Model predictive control(MPC)has the capability of fast track response,thus it has been widely used in the field of power electronics.In this paper,a grid-connected control method based on MPC of a three-phase Z-source in verter is presented for the permanent magnet direct-drive wind power generation system.In consideration of the characteristics of the three-phase Z-source inverter,nine switch states of the Z-source inverter are rolling calculated by the pre dictive model in each sampling period.The appropriate switch states are selected according to the principle of minimiz ing the cost function,then they are directly delivered to the inverter bridge without a modulator.In this way,the capaci tor voltage of Z-source network and the grid-connected active power can be controlled successfully,and the unity power factor running can be realized.Finally,a simulation model is built up in Matlab/Simulink.Results show that the gridconnected active power can be directly controlled with good dynamic performance using the three-phase Z-source invert er under MPC.The correctness and validity of theoretical analysis are verified through simulations.