Power systems are going through a paradigm change from centralized generation, to distributed generation, and further on to smart grids. In order to make power systems more secure, more efficient, more resilient to threats and friendlier to the environment, a huge number of heterogeneous players, including renewable energy sources, electric vehicles, and storage systems etc. on the supply side and different types of smart loads on the demand side, are being connected to power systems to form smart grids. Because of the heterogeneous nature and the huge number of players involved, it is a great challenge to find a system architecture so that all heterogeneous players could work together to maintain system stability and achieve desired performance. In this talk, an autonomous distributed control architecture will be presented from the systems perspective for the next-generation smart grid, after homogenizing the heterogeneous players with the synchronization mechanism of synchronous machines. Enabling technologies will be presented to implement this architecture via operating power electronic converters as virtual synchronous machines. All the distributed controllers require only the information available locally and communicate with each other through the dynamics of power systems, rather than through an additional communication network. They equally and actively take part in the system regulation via independent individual actions to achieve the same control objective, leading to synchronized and democratized (SYNDEM) smart grids. This holistic solution could considerably enhance the stability, scalability, operability and reliability of the next-generation smart grid.