基于VSG的永磁直驱风电机组惯量支撑控制策略

Inertia Support Control Strategy for Permanent Magnet Direct-Drive Wind Turbines Based on VSG

风电并网容量比重不断加大,减弱了系统的调频能力与惯量支撑能力,电网失稳日益严重。针对这些问题提出了基于虚拟同步机(VSG)的永磁直驱风电机组的控制方案。模仿同步机的功频控制特点,使系统具有惯量响应能力。风电机组经PWM变流器并网,在机侧变流器利用直流电压外环和电流内环控制,维持直流母线电压稳定,VSG从网侧变流器接入,通过设计有功频率和无功电压控制方案,对系统进行调频、调压。使用Matlab软件搭建模型,调整仿真参数,仿真结果表明,该控制方案使系统可以模拟同步发电机的惯量响应特性,能够有效地解决由于风速或者电网负荷改变引起的频率震荡问题。

In view of the increasing proportion of gridconnected wind power capacity,which weakens the system's frequency modulation ability and inertia support ability,and the increasingly serious problem of grid instability,a control scheme of the virtual synchronous generator(VSG)-based permanent magnet direct drive wind turbine is proposed in this paper.By simulating the power frequency control characteristics of the synchronous machine,the system has been enabled the inertia response capability.The wind turbines are connected to the grid through the PWM converter.On the generator-side,the converter uses the DC voltage outer loop and the current inner loop to maintain the DC bus voltage stability while the VSG is connected from the grid-side converter,and the frequency and voltage of the system can be adjusted by designing the active power frequency and reactive voltage control schemes.The Matlab software is used to build the model and adjust the simulation parameters,and the simulation results show that the control scheme enables the system to simulate the inertia response characteristics of the synchronous generator,and can effectively solve the frequency oscillation problem caused by changes in wind speed or grid load.