基于降阶矢量比例积分器的MMC-HVDC不平衡控制策略

发布时间：2018-05-13 10:42

本文选题：模块化多电平换流器 + 不平衡控制　；参考：《中国电机工程学报》2016年13期

【摘要】：为提高模块化多电平高压直流输电系统在电网电压不平衡时的运行能力,提出一种新型不平衡控制策略。该策略在正向同步旋转坐标系下电流比例积分(proportional integral,PI)闭环控制的基础上引入以抑制负序电流、抑制有功波动或抑制无功波动为控制目标的辅助控制器,避免了电压、电流正负序分解和繁琐的指令电流计算。为实现上述3种控制目标,对二阶广义积分器(second order generalized integrator,SOGI)、降阶广义积分器(reduced order generalized integrator,ROGI)和降阶矢量比例积分器(reduced order vector proportional integrator,ROVPI)这3种控制器进行了研究对比。研究发现,SOGI作为辅助控制器将产生3次正序谐波,导致电流畸变;与ROGI相比,ROVPI具有更好的控制精度和相位裕度,因此选择ROVPI作为辅助控制器。仿真结果验证所提不平衡控制策略的正确性和有效性。
[Abstract]:In order to improve the operation capability of modularized multilevel HVDC transmission system when the voltage of power network is unbalanced, a new unbalanced control strategy is proposed. Based on the proportional integral PI-based closed-loop control in the forward synchronous coordinate system, this strategy introduces an auxiliary controller which can suppress the negative sequence current, suppress the active power fluctuation or the reactive power fluctuation, and avoid the voltage. Current positive and negative sequence decomposition and tedious instruction current calculation. In order to realize the above three control objectives, three kinds of controllers, namely, second order generalized integrator, reduced order generalized integrator, and reduced vector proportional integrator, are studied and compared. It is found that the third positive sequence harmonics will be generated as the auxiliary controller and the ROGI has better control precision and phase margin. Therefore, ROVPI is chosen as the auxiliary controller. Simulation results verify the correctness and effectiveness of the proposed unbalanced control strategy.
【作者单位】：新能源电力系统国家重点实验室(华北电力大学);北京四方继保自动化股份有限公司;电力系统及发电设备控制和仿真国家重点实验室(清华大学);
【分类号】：TM46

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