集中式多电平调制策略的状态机型脉冲分配器设计与实现  

Design and Implementation of a State Machine Based Pulse Distributor for Integrated Multilevel Modulation Strategies

作　　者：孙毅超[1] 季振东[2] 李东野[1] 乐越 赵剑锋[1] 黄允凯[1] 

机构地区：[1]东南大学电气工程学院,江苏省南京市210096 [2]南京理工大学自动化学院,江苏省南京市210094

出　　处：《中国电机工程学报》2017年第16期4758-4768,共11页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51477030)~~

摘　　要：脉冲分配方式是实现如载波层叠调制、最近电平逼近调制等集中式多电平调制策略的主要难点。针对含冗余状态的模块组合型多电平变换器,提出一种应用于集中式调制策略的状态机型脉冲分配器设计与实现方法。该脉冲分配器致力于使电平化后的调制信号遍历状态机中的所有路径,从而各个模块的开关次数在各个电平等级都得到均匀的分配,实现了模块电容电压的自然平衡特性。同时,针对低频类调制策略无法自动遍历状态机的情形,该状态机具有状态强制切换功能,在最大限度维持模块开关频率低频特性的条件下,使其能够在合理的时间范围内遍历状态机。通过基于模块化多电平变换器平台的仿真与实验验证了状态机型脉冲分配器的有效性。The way of pulse distribution is widely considered as one of the research challenges of integrated multilevel modulation strategies. This paper proposed a state machine based pulse distributor for such strategies focusing on evenly distributing the pulse transients among all the modules. By appropriately selecting the redundant states for every given level, the total turn-on and turn-off periods of each module were controlled to be approximately identical which guarantees the natural balance of the DC-link capacitor voltages. Moreover, a state change enforcement mechanism was designed for lower frequency scenarios where only part of the state machine can be travelled through. By following this mechanism, the states and pathways in the state machine were able to be fully selected within an appropriate period. In the meantime, minima/ extra switch transitions were assured. Therefore, the natural balance of the DC-link voltages in lower frequency conditions was achieved with almost the same module switching frequencies. Simulation and experimental results obtained from a MMC platform validate the effectiveness of this pulse distributor.

关 键 词：模块组合多电平变换器 载波层叠调制 最近电平逼近调制 混合调制 脉冲分配 状态机 电压平衡 

分 类 号：TM46[电气工程—电器]