Model predictive control (MPC) methods are popularly employed in modular multilevel converters (MMCs) due to their fast dynamic response and multiobjective control capability. However, they present some inherent problems, such as computational complexity, variable switching frequency, poor steady-state performance, and tedious weighting factor selection. This article develops a deadbeat predictive current control method for MMCs. This method can realize the reference tracking of ac current and circulating current in one sampling period without error, and thus provide a fast dynamic response as conventional MPC methods. Besides, switching state or voltage level evaluation, cost function calculation as well as weighting factor selection are not required. Therefore, it has a very low calculation burden, which is independent of the number of submodules (SMs). Since a modulation stage is utilized, a fixed switching frequency and consequently a satisfactory steady-state performance are obtained. The effects of time delay, parameter mismatch, and SM capacitor voltage ripple on the control algorithm are discussed. Also, the corresponding improvement measures are provided to further enhance the steady-state performance and system stability of MMCs. The effectiveness and performance of the developed control algorithm are verified by experimental results.

中文翻译：

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具有增强的稳态性能和稳定性的模块化多电平转换器的无差拍预测电流控制

模型预测控制 (MPC) 方法因其快速动态响应和多目标控制能力而广泛用于模块化多电平转换器 (MMC)。然而，它们存在一些固有问题，例如计算复杂性、可变开关频率、稳态性能差以及繁琐的加权因子选择。本文开发了一种用于 MMC 的无差拍预测电流控制方法。该方法可以在一个采样周期内无误差地实现交流电流和环流的参考跟踪，从而提供与传统MPC方法一样的快速动态响应。此外，不需要开关状态或电压电平评估、成本函数计算以及加权因子选择。因此，它的计算负担非常低，这与子模块 (SM) 的数量无关。由于使用了调制级，因此获得了固定的开关频率并因此获得了令人满意的稳态性能。讨论了时间延迟、参数失配和 SM 电容器电压纹波对控制算法的影响。此外，还提供了相应的改进措施，以进一步提高 MMC 的稳态性能和系统稳定性。实验结果验证了所开发控制算法的有效性和性能。提供了相应的改进措施，以进一步提高MMC的稳态性能和系统稳定性。实验结果验证了所开发控制算法的有效性和性能。提供了相应的改进措施，以进一步提高MMC的稳态性能和系统稳定性。实验结果验证了所开发控制算法的有效性和性能。