Synchronization aspects of single phase SPWM inverters for microgrid mode of operation

This paper deals with inverters which are to be synchronized to share the common load of microgrid. The microgrid under consideration is in OFF grid condition and hence one of the inverters is designed as master and the remaining are designed for slave mode of operation. A state-of-the-art synchronization strategy is developed for the initial synchronization of the inverter during startup period. The microgrid synchronism is then maintained with this master-slave configuration of inverters and the amount of load that can be fed to the microgrid, is adjusted or decided by the user. The control strategy is so designed that the load can always be fed at unity power factor. The SPWM technique and an output filter are utilized to reduce the voltage harmonics to a minimum level and thus produce an almost sinusoidal terminal voltage. The entire design is simulated with MATLAB Simulink and the desired output is achieved.