This article presented a new structure for the grid-connected multilevel inverters (MLIs) circuit with the ability of the cascaded connection. The proposed inverter is capable of transformerless connection of distributed generation resources to the network. The control system manages the power injection to the grid by minimizing the output current harmonics as well as exchanging reactive power with the grid. The self-balancing state of the capacitors’ voltage is occurred only with the switching technique without any measurement sensors. An enhanced phase-locked loop (EPLL) and a proportional resonant (PR) controller are employed for the proposed asymmetric MLI. An important feature of the proposed inverter is the ability of stable performance and fast dynamics of the control system to the changes of the reference values. Simulation and experimental results are presented in order to validate the performance accuracy of the proposed MLI.

中文翻译：

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并网不对称级联多电平逆变器的运行与控制

本文介绍了具有级联连接能力的并网多电平逆变器（MLI）电路的新结构。所提出的逆变器能够将分布式发电资源与网络进行无变压器连接。控制系统通过最小化输出电流谐波以及与电网交换无功功率来管理对电网的功率注入。电容器电压的自平衡状态仅在不使用任何测量传感器的开关技术下才会发生。所提出的非对称MLI采用了增强型锁相环（EPLL）和比例谐振（PR）控制器。所提出的逆变器的一个重要特征是控制系统具有稳定的性能和快速的动态能力，能够随参考值的变化而变化。