A new multifunctional inverter control structure is proposed in this paper by embedding the harmonic and unbalance regulators into the virtual synchronous machine (VSM). While including the harmonic and unbalance regulators, inverters can provide support to the grid not only as VSMs, but also as active power filters (APFs) and unbalance conditioners. Different from the traditional multifunctional inverter in the stationary frame, the proposed method is implemented in the synchronous reference frame using the vector proportional-integral controllers without high pass filter for APF. Moreover, with VSM for power control and frequency tracking, harmonic and unbalance regulators can use the phase tracked by VSM so that the adaptive control is achieved regardless of the frequency variations. As a result, the simplified control structure with more operation modes is available without phase-locked loop (PLL) and unbalance regulators can reuse the voltage/current control of positive sequence. Furthermore, control decoupling condition of different functions is analysed to ensure the independent design of each function. Finally, the proposed structure is verified by MATLAB/Simulink and experiments.

通过将谐波和不平衡调节器嵌入虚拟同步机（VSM）中，提出了一种新型的多功能逆变器控制结构。在包括谐波和不平衡调节器的同时，逆变器不仅可以作为VSM，而且可以作为有源功率滤波器（APF）和不平衡调节器，为电网提供支持。与传统的多功能逆变器在固定框架中不同，该方法是在同步参考框架中使用矢量比例积分控制器实现的，而无需使用用于APF的高通滤波器。此外，借助VSM进行功率控制和频率跟踪，谐波和不平衡调节器可以使用VSM跟踪的相位，从而无论频率如何变化都可以实现自适应控制。作为结果，无需锁相环（PLL）即可使用具有更多操作模式的简化控制结构，并且不平衡调节器可以重复使用正序的电压/电流控制。此外，分析了不同功能的控制解耦条件，以确保每个功能的独立设计。最后，通过MATLAB / Simulink和实验对提出的结构进行了验证。