DC-link Voltage Control of a Full Power Converter for Wind Generator Operating in Weak-Grid Systems
DC-link Voltage Control of a Full Power Converter for Wind Generator Operating in Weak-Grid Systems
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DOI：
10.1109/apec.2008.4522807
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发表时间：
2008-05
影响因子：
6.7
通讯作者：
Xibo Yuan;Fei Wang;D. Boroyevich;Yongdong Li;R. Burgos
中科院分区：
文献类型：
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作者：
Xibo Yuan;Fei Wang;D. Boroyevich;Yongdong Li;R. Burgos
当风电在电网电能中占很大比例时，可能需要帮助电网进行电压和频率调节。本文研究了一种采用全功率电压型变流器的永磁风力发电机组在弱网模式下，直流侧电压需要从发电机侧而不是电网侧进行控制。建立了风力发电机、直流环节储能和负荷的能量关系。右半平面固有零点、风电特性、机械系统惯量和直流环节储能被确定为控制的物理极限。在了解系统能量关系和局限性的基础上，提出了一种混合自适应控制算法，该算法搜索最优的发电机加速度，以获得与负荷功率变化匹配的最大风电功率变化率。通过对1.5 MW风电系统的仿真和基于1kW、DSP-/field-programmable-gate-array-controlled，永磁发电机试验台的实验，验证了所提出的控制方案。结果表明，发电机侧变流器通过对发电机转速的控制来调节直流环节是可行的。文中还研究了一些重要的应用问题，包括直流环节储能要求、风速变化的影响以及弱网和强网模式之间的控制过渡。
When the wind power accounts for a large portion of the grid power, it may need to help the grid voltage and frequency regulation. This paper investigates a permanent-magnet wind generator with a full power voltage-source converter in weak-grid mode, where the DC-link voltage needs to be controlled from the generator side instead of the grid side. The energy relationship of the wind generator, DC-link energy storage, and load is established. An intrinsic right-half-plane zero, together with the wind power characteristics, the mechanical system inertia, and the DC-link energy storage, is identified as the physical limitations for the control. With the understanding of the system energy relationship and limitations, a hybrid adaptive control algorithm is proposed that searches for the optimal generator acceleration to achieve the maximum wind generator power change rate to match the load power variation. The proposed control scheme is verified through simulation of a 1.5-MW wind system as well as through the experiment of a scaled 1-kW, DSP-/field-programmable-gate-array-controlled, permanent-magnet-generator-based test bed. The results show that it is feasible to regulate DC link by the generator-side converter through the generator speed control. Some important applications issues are also investigated, including the DC-link energy storage requirement, wind speed change impact, and control transition between the weak-grid and strong-grid modes.