MANAGEMENT OF RENEWABLE ENERGY SOURCES UNDER GRID FAULT CONDITIONS

Presentation and development of five current control techniques to performance some output power features. The techniques are the IARC, BPSC, PNSC, AARC, FPNSC. Through the IARC it is possible to performe a constant active and reactive power injecting an unbalanced set of currents that feature higher harmonics than the foundamental. BPSC performs oscillating output powers at the double of the foundamental injecting a set of balanced currents to the grid. PNSC performs a constant active power if the reactive power reference is set to zero. The same consideration can be done for the reactive power: if the active power reference is set to zero the reactive power will be free of oscillations. AARC performs no oscillation for the power reference set to zero and a lower value of peak current respect to PNSC. FPNSC is the more flexible technique between all the techniques: it performs no active power oscillation by modulating the amount of positive and negative sequence of reference currents injected to the grid through the selection of the value of two regulation parameters, k1 and k2. All the techniques are developed to maximize the amount of reactive power injectable to the grid to support the grid during the fault and avoid the protection of the inverter for overcurrent.