多通道三电平风力发电系统协同控制策略研究

Collaborative Control Strategies for Multi-channel Three-level Wind Energy Conversion System

该文研究多通道二极管钳位型三电平风力发电系统控制策略,包括系统正常运行时电机侧和电网侧协同控制及电机绕组、器件故障时的容错运行方法。电机侧采用多相永磁同步发电机,设计基于最优转矩控制和空间矢量解耦的发电机矢量控制策略,提出解耦分组型多相三电平变流器空间矢量调制策略,在转矩产生平面采用前馈补偿电压控制方法消除耦合项,在谐波平面采用闭环比例谐振控制器,补偿电机参数不对称和反电动势引起的谐波电流。电网侧采用多通道三电平变流器并联结构,设计基于无功功率控制、直流侧电容电压控制的控制策略及基于零序电压注入的并联变流器环流抑制策略。此外,论文讨论多通道三电平风力发电系统故障状态下的容错运行方法。通过实验对提出的控制策略的有效性进行验证。

The control strategies of multi-channel diode neutral-point-clamping three-level wind power generation system were investigated, including the control strategies on machine side and grid side under normal condition and fault-tolerant operation under faults in machine windings and devices. The multiphase permanent magnet generator was adopted on machine side. The vector control scheme was proposed based on optimum torque control and vector space decoupling(VSD) on machine side. In particular, a decoupled VSD switching strategy was proposed for multi-channel three-level inverter. Hence, the voltage control method with feedforward compensation was designed on torque-generating subspace, and the closed-loop proportional resonant controller was designed on harmonic subspace, which can suppress the harmonic current components caused by asymmetry in machine parameters and harmonics in back EMF. The configuration of paralleled three-level converters was used on grid side, where the control schemes of reactive power regulation, DC link voltage control and circulating current suppression using zero-sequence voltage injection were designed. Besides, fault-tolerant control strategies were discussed for faulty conditions of multi-channel three-level wind power generation system. Finally, the experiments were presented to verify the validity of the proposed control schemes.