基于PLC的直驱永磁风电机组机械谐振自动控制方法

Automatic Control Method of Mechanical Resonance for Direct-Driven Permanent Magnet Wind Turbine Based on PLC

为降低变流器的滤波器滤波电容扩大引起的电力系统谐振恶化情况,提出了基于可编程逻辑控制器(PLC)的直驱永磁风电机组机械谐振自动控制方法。首先,基于直驱永磁风电机组结构,构建风力机空气动力模型,分析全功率变流器的功率特性,研究直驱永磁风电机组机械谐振特性;其次,结合研究结果采用PLC编制相关控制程序,应用参数自整定模糊PID控制方法在PLC的中央处理器内保存、处理所编制的程序以及风电机组相关设置;最后,经由中央处理器调动相关指令信息后,以信号形式返回至执行机构完成指令,实现直驱永磁风电机组机械谐振控制。实验结果表明:该方法可较好地抑制直驱永磁风电机组机械谐波电流;全功率变流器并网三相输出侧的电压、电流可在0.10 s内恢复稳定,滤波器三相、单相输出侧的输出电压分别在约0.02、0.12 s接近稳定;同时可有效抑制非线性负载对直驱永磁风电机组电流的扰动。

In order to reduce the deterioration of power system resonance caused by the expansion of filter capacitance of converter filter,an automatic control method of mechanical resonance of direct drive permanent magnet wind turbine based on programmable logic controller(PLC)is proposed.Based on the structure of direct drive permanent magnet wind turbine,the aerodynamic model of wind turbine is constructed.By analyzing the power characteristics of full power converter,the mechanical resonance characteristics of direct drive permanent magnet wind turbine are studied.Combined with the research results,the relevant control program is compiled by PLC,and the parameter self-tuning fuzzy PID control method is applied to save and process the compiled program and relevant settings of wind turbine in the central processor of PLC.After the relevant command information is transferred through the central processing unit,it returns to the actuator in the form of signal to complete the command,so as to realize the mechanical resonance control of direct drive permanent magnet wind turbine.The experimental results show that this method can suppress the mechanical harmonic current of direct drive permanent magnet wind turbine.The voltage and current at the three-phase output side of the grid connected full power converter quickly recover and stabilize within 0.10 s,and the output voltage at the three-phase and single-phase output sides of the filter is nearly stable at about 0.02 s and 0.12 s respectively.It can effectively suppress the disturbance of nonlinear load to the current of direct drive permanent magnet wind turbine.