Droop Control of Inverter Interfaced Distributed Generation

In recent times, interest in renewable energy-based Distributed Generation (DG) is increasing rapidly. These sources are connected to AC bus through inverter interface. During islanded mode, output voltage and frequency of sources should be properly regulated for stable operation and it is done by applying control action on inverter. The paper presents a control strategy for controlling inverter output. It deals with active power-frequency and reactive power-voltage (P-f/Q-V) droop control strategy for voltage and frequency regulation. Droop control can be implemented for communication-less control of inverter-based DG units. The control adjusts voltage and frequency of individual generating unit according to the power flow. P-f droop uses real power(P) of the DG unit to decide the operating frequency and Q-V droop uses reactive power(Q) to decide operating voltage. The simulation is conducted in the MATLAB/Simulink and results are analyzed. Results show that droop control is an effective technique for the control of inverters that are interfaced with distributed generation sources.