A hybrid HVDC converter based on M2C and diode rectifiers without DC capacitors for offshore wind farm integration
A hybrid HVDC converter based on M2C and diode rectifiers without DC capacitors for offshore wind farm integration
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DOI：
10.1016/j.ijepes.2021.107260
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发表时间：
2021
影响因子：
5.2
通讯作者：
T. Nguyen;N. Quach
中科院分区：
文献类型：
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作者：
T. Nguyen;N. Quach
提出了一种将海上风电场的电能传输到大陆电网的高压直流换流器系统的新拓扑结构。高压直流换流器由基于模块化多电平换流器（M2 C）的电压源换流器（VSC）和无直流电容器的12脉冲二极管整流器（12 PD）的混合串联方案与海上站的WF和陆上站的全尺寸M2 C集成而成。在该方案中，HVDC链路电压由陆上站中的M2 C控制，而海上侧的M2 C作为受控电压源操作以维持海上AC电压。反馈线性化技术应用于海上电站的M2 C，用于调节海上交流电压，与基于线性控制理论的方案相比，该方法为电压控制VSC的非线性模型提供了更好的性能。此外，通过利用二极管并消除12 PD的输出端子处的DC电容器，所提出的HVDC转换器拓扑在效率、资本投资成本、维护和占地面积方面提供优于全尺寸M2 C HVDC系统的优点。通过525-kV 600-MW HVDC系统与风力涡轮机发电机集成的仿真试验，证明了所提出的拓扑。该换流器的基本操作也证明了在实验室中的一个缩小规模的HVDC系统的实验结果。
In this paper, a new topology of high-voltage direct current (HVDC) converter system for transmitting the power from offshore wind farms (OWF) to the mainland grid is proposed. The presented HVDC converter is composed of a hybrid series connection scheme of voltage-source converters (VSC) based on M2C (modular multilevel converter) and twelve-pulse diode rectifiers (12PD) without DC capacitors integrating with the WFs in the offshore station and a full-scaled M2C in an onshore station. In this scheme, the HVDC-link voltage is controlled by the M2C in the onshore station, while the M2C in the offshore side is operated as controlled-voltage source to maintain the offshore AC voltages. A feedback linearization technique is applied to the M2C in the offshore station for regulating the offshore AC voltages, which offers a better performance for a nonlinear model of the voltage-controlled VSC when compared to schemes based on the linear control theory. Furthermore, with the utilization of the diodes and elimination of DC capacitors at the output terminal of the 12PD, the proposed HVDC converter topology offers advantages over the full-scaled M2C HVDC systems in terms of efficiency, capital investment costs, maintenance, and footprint. The proposed topology is proved through the simulation tests for a 525-kV 600-MW HVDC system integrating with wind turbine generators. Fundamental operation of the converter is also demonstrated by the experimental results for a reduced-scale HVDC system in laboratory.