Abstract:

In this work, grid-tied series-connected (SC) inverter system is presented in order to improve the efficiency, overcome the redundancy-reliability problems and also to reduce the cost of solar panel. In this system, each photovoltaic (PV) array is interfaced with an inverter and a boost converter to boost up the PV panel output voltage. Maximum Power Point Tracking (MPPT) is used to maximize the solar power. Frequency of series connected-inverters is AC in nature. The output of inverters is connected in series to match with the utility grid voltage. Meanwhile, Synchronous reference frame (D-Q) control is used for the series- connected inverters to control the active power and the reactive power. MATLAB simulation is carried out to analyze the performance. In this work, the internal control method of inverter is implemented. By avoiding external control methods of inverter, larger number of conversion stages could be avoided and further results in reduction of losses. Bipolar SPWM (sinusoidal pulse width modulation) is used to provide switching sequences to the grid-tied inverter to minimize the switching losses. Simulation results shows the effectiveness of designed controller which is used to provide the active power from dc bus to grid. The proposed control strategy provides quality in output current and output voltage i.e they are having less harmonic distortion and voltage and frequency should be within limits

Description:

Photovoltaic generation; Series-connected inverter; MPPT Algorithm; Utility grid; Boost converter; Synchronous D-Q reference frame control.