12. A Master–Slave Control in Grid-Connected Applications

In this chapter, a novel hybrid voltage/current control scheme with low communication burden is introduced for series-type inverters in a decentralized manner. All the inverter units are controlled by their individual local controllers without a real-time central global communication. Among them, a few inverters serve as the Current-Controlled Inverters (CCIs) to regulate the grid current, and the rest inverters work as the Voltage-Controlled Inverters (VCIs). Under this control architecture, five main control targets are achieved: (1) frequency self-synchronization of each VCI inverter based on local current phase-angle signals; (2) fault-tolerant capability of all inverters without one-to-all-failure; (3) high disturbance-rejection-capability to grid variations; (4) adjustable grid power factor (PF); (5) independent power control for inverters with unbalanced power sources.