A hybrid modular multilevel converter (HMMC) topology based on a bidirectional diode clamp circuit is proposed in this paper. The proposed topology ensures that the voltages at the ends of the capacitance between the two leads of each sub-module in the same phase are clamped to be equal to each other through the diode clamp circuit. The balancing process through the diode clamp circuit is bidirectional, which is only achieved by the diode clamp circuit. This topology has two advantages when compared with the traditional voltage balance control method. First, the framework used for controlling the entire structure is simplified while the link controlling the voltage balance is eliminated. Second, the control schemes used for the voltage balance are simplified, and the number of the corresponding high-frequency voltage sensors is reduced. Hence, the complexity of the system control is decreased, and communication is realized more easily. When compared with other voltage balancing circuits, the proposed circuit achieves bidirectional equalization and reduces the usage of the inductors. Then, the hardware cost is reduced. Finally, the feasibility of the proposed converter is verified by simulation results given in MATLAB/Simulink.

本文提出了一种基于双向二极管钳位电路的混合模块化多电平转换器 (HMMC) 拓扑。所提出的拓扑结构确保通过二极管钳位电路将同相每个子模块的两条引线之间的电容两端的电压钳位为彼此相等。通过二极管钳位电路的平衡过程是双向的，只有通过二极管钳位电路才能实现。与传统的电压平衡控制方法相比，这种拓扑结构有两个优点。首先，简化了用于控制整个结构的框架，同时取消了控制电压平衡的环节。其次，简化了用于电压平衡的控制方案，减少了相应的高频电压传感器的数量。因此，降低了系统控制的复杂度，更容易实现通信。与其他电压均衡电路相比，该电路实现了双向均衡，减少了电感的使用。然后，降低了硬件成本。最后，通过MATLAB/Simulink 中给出的仿真结果验证了所提出的转换器的可行性。