中文摘要：

电平数较多的模块化多电平换流器（MMC）系统含大量高频开断的开关器件,其多模块的拓扑结构和复杂的协调控制导致基于纯物理装置的仿真实验建模面临诸多困难。针对这一问题,设计了一种MMC控制器并开发出样机,建立了基于实时数字仿真器（RTDS）和物理控制装置的半实物混合仿真实验平台。其中,一次系统采用2.5μs小步长,能实现上百电平MMC系统的高精度仿真。控制器采用了多核技术,将并行的阀控部分分配在不同核之间,满足了实时控制的要求。通过多个稳态和暂态实验对平台实验能力和控制器的合理性进行验证,结果表明,此平台可灵活实现不同调制和控制策略,各项控制目标响应迅速且跟踪准确。所建立实验平台可以用于主电路设计论证、控制策略研究测试、控制器参数优化、柔性直流系统同大电网的交互研究等领域。

英文摘要：

Owing to a large number of power semiconductors in the modularized multilevel converter （MMC） and its complicated coordinated control, the physical verification for MMC faces many difficulties. To solve this problem, a hardware in-the-loop simulation platform for high level MMC is established between the real-time digital simulator （RTDS） and the physical MMC controller. On this platform, the converter valve is simulated with the small time step of 2.5 microsecond, which is quite qualified for high precision simulation of a hundred level MMC system. By adopting multicore technology and distributing the parallel valve control between different cores, the designed controller meets the requirements of real-time control. Several steady and transient state experiments are carried out to verify the functions of the designed platform and the rationality of the designed controller. The results show that different modulation and control strategies can be implemented on the simulation platform and each control objective has good tracking accuracy and quick dynamic response. The proposed platform can be used in many fields, such as the design of main circuit for MMC-high voltage direct current （HVDC）, the study and test of control strategies, the optimization of control parameters, the research on interaction between MMC-HVDC and large power grid and so on.