Voltage and current control of microgrid under unbalanced load

For the problem of the three-phase unbalanced load in the microgrid, a control strategy based on the delta-connected static synchronous compensator (SSC) is adopted to achieve both reactive power compensation and unbalanced load compensation at the same time. Firstly, the mathematical model of the delta-connected SSC is established to analyze the principle of SSC to compensate the unbalanced loads. Secondly, the control strategy of SSC is studied from three aspects, and the compensation current is accurately detected based on the instantaneous power reference current detection method. Using dc control method to control the output current, so that SSC can accurately output compensation current. In order to reduce the impact of the negative sequence current generated by the unbalanced load on the voltage of the dc side, balance control method is a dopted for dc side voltage, the active component is added to the reference current to balance the total voltage, and the zero sequence current isadded to the reference current. Thephase-to-phase voltage is balanced by means of sequencecurrent components. Finally,asimulation modelis established in the Matlab/Simulink environment to verify the relevant theoretical analysis and the proposed control strategy, the results show the effectiveness of the designed control strategy.