基于PLECS的直驱永磁风电系统直接功率控制研究

在研究风力机特性和永磁同步发电机运行机理的基础上,建立了直驱式永磁风力发电系统数学模型,在实现最大风能捕获的同时,分析了负载变化对发电机侧电能转换单元控制参数的影响。对于网侧逆变器控制,采用基于直轴虚拟电网磁链定向的直接功率控制,避免了对电网电压的检测和电流闭环控制,有效简化了系统结构,提高了工作可靠性。通过在Matlab/Simulink环境下嵌入PLECS工具箱进行仿真研究,结果表明该系统具有较好的控制鲁棒性和低电压穿越能力,进一步验证了基于PLECS工具箱进行风电系统建模与仿真的可行性。

Direct Power Control of Direct-driven Wind Energy Conversion System Based on PLECS

Based on the mechanism of wind turbine and characteristics of permanent magnet synchronous generator(PMSG),the mathematic models of direct-driven wind power generation system with PMSG were established.The relations between booster chopper modulation and load impedance variation were analyzed so as to estimate the optimal rotor speed of the wind turbine and implement the maximum power point tracking(MPPT).A virtual grid flux based direct power control(DPC) with space vector modulation for grid-connected converter was proposed.The active and reactive powers were used as the control variables instead of the currents applied in conventional voltage oriented control method.Moreover,grid voltage sensors were replaced by a virtual flux(VF) estimator.The complete model of the wind energy conversion system was established through the Matlab/Simulink PLECS Toolbox.The digital simulation results confirm that the low voltage ride through capability and control robustness,evaluating the feasibility of PLECS in modeling and simulation of wind energy conversion system.